Changelog

All notable changes to this project will be documented in this file. This project adheres to Semantic Versioning.

Unreleased

API changes

As a part of public API stabilization, data classes are no longer used in the public API. As of that, functions like copy() or componentN() (used for destructuring declarations) are not available anymore. This is a binary incompatible change, breaking backwards compatibility. (#2133)
Align names of Rule classes, file and RULE_ID constants (#2176). Rule class MultilineExpressionWrapping has been renamed to MultilineExpressionWrappingRule. Rule class StatementWrapping has been renamed to StatementWrappingRule. RULE_ID constants below are moved to a different Java class at compile time. Each rule provided by Ktlint is to be accompanied by a RULE_ID constant that can be used in the VisitorModifier.RunAfter. Filenames did not comply with standard that it should end with Rule suffix.

RULE ID	Old Java class name	New Java class name
FUNCTION_EXPRESSION_BODY_RULE_ID	FunctionExpressionBodyKt	FunctionExpressionBodyRuleKt
FUNCTION_LITERAL_RULE_ID	FunctionLiteralKt	FunctionLiteralRuleKt
MULTILINE_EXPRESSION_WRAPPING_RULE_ID	MultilineExpressionWrappingKt	MultilineExpressionWrappingRuleKt
NO_BLANK_LINE_IN_LIST_RULE_ID	NoBlankLineInListKt	NoBlankLineInListRuleKt
NO_EMPTY_FILE_RULE_ID	(not applicable)	NoEmptyFileRuleKt

Custom rule providers

Class "org.jetbrains.kotlin.com.intellij.treeCopyHandler" is no longer registered as extension point for the compiler as this is not supported in Kotlin 1.9. Please test your custom rules. In case of unexpected exceptions during formatting of code, see #2044 for possible remediation.

Added

Add experimental rule class-signature. This rule rewrites the class header to a consistent format. In code style ktlint_official, super types are always wrapped to a separate line. In other code styles, super types are only wrapped in classes having multiple super types. Especially for code style ktlint_official the class headers are rewritten in a more consistent format. See examples in documentation. class-signature #875, #1349
Add experimental rule function-expression-body. This rule rewrites function bodies only contain a return or throw expression to an expression body. #2150
Add new experimental rule statement-wrapping which ensures function, class, or other blocks statement body doesn't start or end at starting or ending braces of the block (#1938). This rule was added in 0.50 release, but was never executed outside the unit tests. The rule is now added to the StandardRuleSetProvider (#2170)
Add experimental rule chain-method-continuation to the ktlint_official code style, but it can be enabled explicitly for the other code styles as well. This rule requires the operators (. or ?.) for chaining method calls, to be aligned with each other. This rule is enabled by (#1953)

Removed

Fixed

Allow to disable ktlint in .editorconfig for a glob (#2100)
Fix wrapping of nested function literals wrapping (#2106)
Do not indent class body for classes having a long super type list in code style ktlint_official as it is inconsistent compared to other class bodies indent #2115
In code style ktlint_official do not indent the closing parenthesis of a PARENTHESIZED expression indent #920
Log message Format was not able to resolve all violations which (theoretically) can be autocorrected in file ... in 3 consecutive runs of format is now only displayed in case a new ktlint rule is actually needed. #2129
Fix wrapping of function signature in case the opening brace of the function body block exceeds the maximum line length. Fix upsert of whitespace into composite nodes. function-signature #2130
Fix spacing around colon in annotations spacing-around-colon (#2093)
Do not wrap a binary expression after an elvis operator in case the max line length is exceeded (#2128)
Fix indent of IS_EXPRESSION, PREFIX_EXPRESSION and POSTFIX_EXPRESSION in case it contains a linebreak indent #2094
Fix false positive regarding property that potentially can contain data which is mutable. property-naming #2140
Add new experimental rule function-literal. This rule enforces the parameter list of a function literal to be formatted consistently. function-literal #2121
Store relative path of file in baseline file #2146
Fix null pointer exception for if-else statement with empty THEN block if-else-bracing #2135
Do not wrap a single line enum class statement-wrapping #2177
Fix alignment of type constraints after where keyword in function signature indent #2175
Fix wrapping of multiline postfix expression multiline-expression-wrapping #2183
Remove registration of class "org.jetbrains.kotlin.com.intellij.treeCopyHandler" as extension point for the compiler as this is not supported in the embedded Kotlin compiler version 1.9. Also remove Ktlint CLI command line flag disable-kotlin-extension-point, and parameter enableKotlinCompilerExtensionPoint from KtLintRuleEngine to disable the kotlin extension point #2061
Do not wrap expression after a spread operator multiline-expression-wrapping #2188

Changed

Change default code style to ktlint_official (#2143)
Update dependency gradle to v8.3 (#2186)
Update dependency org.codehaus.janino:janino to v3.1.10 (#2110)
Update dependency com.google.jimfs:jimfs to v1.3.0 (#2112)
As a part of public API stabilization, configure binary-compatibility-validator plugin for compile-time verification of binary compatibility with previous ktlint versions (#2131)
Update dependency org.junit.jupiter:junit-jupiter to v5.10.0 (#2148)
Build the project with Java 20, run test on Java 8, 11, 17 and 20 (#1888)
Update dependency io.github.oshai:kotlin-logging-jvm to v5.1.0 (#2174)
Update kotlin monorepo to v1.9.0 #2113

[0.50.0] - 2023-06-29

Deprecation of ktlint-enable and ktlint-disable directives

The ktlint-disable and ktlint-enable directives are no longer supported. Ktlint rules can now only be suppressed using the @Suppress or @SuppressWarnings annotations. A new rule, internal:ktlint-suppression, is provided to replace the directives with annotations.

API consumers do not need to provide this rule, but it does no harm when done.

The internal:ktlint-suppression rule can not be disabled via the .editorconfig nor via @Suppress or @SuppressWarnings annotations.

Custom Rule Providers need to prepare for Kotlin 1.9

In Kotlin 1.9 the extension points of the embedded kotlin compiler will change. Ktlint only uses the org.jetbrains.kotlin.com.intellij.treeCopyHandler extension point. This extension is not yet supported in 1.9, neither is it documented (#KT-58704). Without this extension point it might happen that your custom rules will throw exceptions during runtime. See #1981.

In Ktlint, 7 out of 77 rules needed small and sometimes bigger changes to become independent of the extension point org.jetbrains.kotlin.com.intellij.treeCopyHandler. The impact on your custom rules may vary dependent on the way the autocorrect has been implemented. When manipulating ASTNodes there seems to be no impact. When, manipulating PsiElements, some functions consistently result in a runtime exception.

Based on the refactoring of the rules as provided by ktlint-ruleset-standard in Ktlint 0.49.x the suggested refactoring is as follows:

Replace LeafElement.replaceWithText(String) with LeafElement.rawReplaceWithText(String).
Replace PsiElement.addAfter(PsiElement, PsiElement) with AstNode.addChild(AstNode, AstNode). Note that this method inserts the new node (first) argument before the second argument node and as of that is not a simple replacement of the PsiElement.addAfter(PsiElement, PsiElement).
Replace PsiElement.replace(PsiElement) with a sequence of AstNode.addChild(AstNode, AstNode) and AstNode.removeChild(AstNode).

Be aware that your custom rules might use other functions which also throw exceptions when the extension point org.jetbrains.kotlin.com.intellij.treeCopyHandler is no longer supported.

In order to help you to analyse and fix the problems with your custom rules, ktlint temporarily supports to disable the extension point org.jetbrains.kotlin.com.intellij.treeCopyHandler using a flag. This flag is available in the Ktlint CLI and in the KtlintRuleEngine. By default, the extension point is enabled like it was in previous versions of ktlint.

At least you should analyse the problems by running your test suits by running ktlint and disabling the extension point. Next you can start with fixing and releasing the updated rules. All rules in this version of ktlint have already been refactored and are not dependent on the extension point anymore. In Ktlint CLI the flag is to be activated with parameter --disable-kotlin-extension-point. API Consumers that use the KtlintRuleEngine directly, have to set property enableKotlinCompilerExtensionPoint to false.

At this point in time, it is not yet decided what the next steps will be. Ktlint might drop the support of the extension points entirely. Or, if the extension point org.jetbrains.kotlin.com.intellij.treeCopyHandler is fully supported at the time that ktlint will be based on kotlin 1.9 it might be kept. In either case, the flag will be dropped in a next version of ktlint.

Added

Add new experimental rule binary-expression-wrapping. This rule wraps a binary expression in case the max line length is exceeded (#1940)
Add flag to disable extension point org.jetbrains.kotlin.com.intellij.treeCopyHandler to analyse impact on custom rules #1981
Add new experimental rule no-empty-file for all code styles. A kotlin (script) file may not be empty (#1074)
Add new experimental rule statement-wrapping which ensures function, class, or other blocks statement body doesn't start or end at starting or ending braces of the block (#1938). Note, although this rule is added in this release, it is never executed except in unit tests.
Add new experimental rule blank-line-before-declaration. This rule requires a blank line before class, function or property declarations (#1939)
Wrap multiple statements on same line wrapping (#1078)
Add new rule ktlint-suppression to replace the ktlint-disable and ktlint-enable directives with annotations. This rule can not be disabled via the .editorconfig (#1947)
Inform user about using --format option of KtLint CLI when finding a violation that can be autocorrected (#1071)

Removed

Code which was deprecated in 0.49.x is removed. Consult changelog of 0.49.x` released for more information. Summary of removed code:

Fixed

Do not flag a (potential) mutable extension property in case the getter is annotated or prefixed with a modifier property-naming (#2024)
Do not merge an annotated expression body with the function signature even if it fits on a single line (#2043)
Ignore property with name serialVersionUID in property-naming (#2045)
Prevent incorrect reporting of violations in case a nullable function type reference exceeds the maximum line length parameter-list-wrapping (#1324)
Prevent false negative on else branch when body contains only chained calls or binary expression (#2057)
Fix indent when property value is wrapped to next line (#2095)

Changed

Fix Java interoperability issues with RuleId and RuleSetId classes. Those classes were defined as value classes in 0.49.0 and 0.49.1. Although the classes were marked with @JvmInline it seems that it is not possible to uses those classes from Java base API Consumers like Spotless. The classes have now been replaced with data classes (#2041)
Update dependency info.picocli:picocli to v4.7.4
Update dependency org.junit.jupiter:junit-jupiter to v5.9.3
Update Kotlin development version to 1.8.22 and Kotlin version to 1.8.22.
Update dependency io.github.detekt.sarif4k:sarif4k to v0.4.0
Update dependency org.jetbrains.dokka:dokka-gradle-plugin to v1.8.20
Run format up to 3 times in case formatting introduces changes which also can be autocorrected (#2084)

0.49.1 - 2023-05-12

Added

Removed

Fixed

Store path of file containing a lint violation relative to the location of the baseline file itself (#1962)
Print absolute path of file in lint violations when flag "--relative" is not specified in Ktlint CLI (#1963)
Handle parameter --code-style=android_studio in Ktlint CLI identical to deprecated parameter --android (#1982)
Prevent nullpointer exception (NPE) if class without body is followed by multiple blank lines until end of file no-consecutive-blank-lines (#1987)
Allow to 'unset' the .editorconfig property ktlint_function_signature_rule_force_multiline_when_parameter_count_greater_or_equal_than when using ktlint_official code style function-signature (#1977)
Prevent nullpointer exception (NPE) if or operator at start of line is followed by dot qualified expression indent (#1993)
Fix indentation of multiline parameter list in function literal indent (#1976)
Restrict indentation of closing quotes to ktlint_official code style to keep formatting of other code styles consistent with 0.48.x and before indent (#1971)
Extract rule no-single-line-block-comment from comment-wrapping rule. The no-single-line-block-comment rule is added as experimental rule to the ktlint_official code style, but it can be enabled explicitly for the other code styles as well. (#1980)
Clean-up unwanted logging dependencies (#1998)
Fix directory traversal for patterns referring to paths outside of current working directory or any of it child directories (#2002)
Prevent multiple expressions on same line separated by semicolon (#1078)

Changed

Moved class Baseline from ktlint-cli to ktlint-cli-reporter-baseline so that Baseline functionality is reusable for API Consumers.

0.49.0 - 2023-04-21

WARNING: This version of KtLint contains a number of breaking changes in KtLint CLI and KtLint API. If you are using KtLint with custom ruleset jars or custom reporter jars, then those need to be upgraded before you can use them with this version of ktlint. Please contact the maintainers of those jars and ask them to upgrade a.s.a.p.

All rule id's in the output of Ktlint are now prefixed with a rule set. Although KtLint currently supports standard rules to be unqualified, users are encouraged to include the rule set id in all references to rules. This includes following:

The --disabled-rules parameter in KtLint CLI.
The .editorconfig properties used to enable or disable rule and rule sets. Note that properties disabled_rules and ktlint_disabled_rules have been removed in this release. See disabled rules for more information.
The source element in the KtLint CLI baseline.xml file. Regenerating this file, fixes all rule references automatically.
The KtLint disable directives ktlint-enable / ktlint-disable and the @Suppress('ktlint:...') annotations.
The VisitorModifier.RunAfterRule.

Moving experimental rules to standard rule set

The experimental rule set has been merged with standard rule set. The rules which formerly were part of the experimental rule set are still being treated as before. The rules will only be run in case .editorconfig property ktlint_experimental is enabled or in case the rule is explicitly enabled.

Note that the prefix experimental: has to be removed from all references to this rule. Check references in:

The --disabled-rules parameter in KtLint CLI.
The .editorconfig properties used to enable or disable rule and rule sets. Note that properties disabled_rules and ktlint_disabled_rules have been removed in this release. See disabled rules for more information.
The KtLint disable directives ktlint-enable / ktlint-disable and the @Suppress('ktlint:...') annotations.
The VisitorModifier.RunAfterRule.

Promote experimental rules to non-experimental

The rules below have been promoted to non-experimental rules:

block-comment-initial-star-alignment
class-naming
comment-wrapping
function-return-type-spacing
function-start-of-body-spacing
function-type-reference-spacing
fun-keyword-spacing
kdoc-wrapping
modifier-list-spacing
nullable-type-spacing
spacing-between-function-name-and-opening-parenthesis
unnecessary-parentheses-before-trailing-lambda

Note that this only affects users that have enabled the standard ruleset while having the experimental rules disabled.

API Changes & RuleSet providers & Reporter Providers

This release is intended to be the last release before the 1.0.x release of ktlint. If all goes as planned, the 1.0.x release does not contain any new breaking changes with except of removal of functionality which is deprecated in this release.

This release contains a lot of breaking changes which aims to improve the future maintainability of Ktlint. If you get stuck while migrating, please reach out to us by creating an issue.

Experimental rules

Rules in custom rule sets can now be marked as experimental by implementing the Rule.Experimental interface on the rule. Rules marked with this interface will only be executed by Ktlint if .editorconfig property ktlint_experimental is enabled or if the rule itself has been enabled explicitly.

When using this feature, experimental rules should not be defined in a separate rule set as that would require a distinct rule set id. When moving a rule from an experimental rule set to a non-experimental rule set this would mean that the qualified rule id changes. For users of such rules this means that ktlint directives to suppress the rule and properties in the .editorconfig files have to be changed.

EditorConfig

Field defaultAndroidValue in class EditorConfigProperty has been renamed to androidStudioCodeStyleDefaultValue. New fields ktlintOfficialCodeStyleDefaultValue and intellijIdeaCodeStyleDefaultValue have been added. Read more about this in the section "Ktlint Official code style".

The .editorconfig properties disabled_rules and ktlint_disabled_rules are no longer supported. Specifying those properties in the editorConfigOverride or editorConfigDefaults result in warnings at runtime.

'Ktlint Official` code style and renaming of existing code styles

A new code style ktlint_official is introduced. This code style is work in progress but will become the default code style in the 1.0 release. Please try out the new code style and provide your feedback via the issue tracker.

This ktlint_official code style combines the best elements from the Kotlin Coding conventions and Android's Kotlin styleguide. This code style also provides additional formatting on topics which are not (explicitly) mentioned in those conventions and style guide. But do note that this code style sometimes formats code in a way which is not accepted by the default code formatters in IntelliJ IDEA and Android Studio. The formatters of those editors produce nicely formatted code in the vast majority of cases. But in a number of edge cases, the formatting contains bugs which are waiting to be fixed for several years. The new code style formats code in a way which is compatible with the default formatting of the editors whenever possible. When using this codestyle, it is best to disable (e.g. not use) code formatting in the editor.

The existing code styles have been renamed to make more clear what the basis of the code style is.

The official code style has been renamed to intellij_idea. Code formatted with this code style aims to be compatible with default formatter of IntelliJ IDEA. This code style is based on Kotlin Coding conventions. If .editorconfig property ktlint_code_style has been set to android then do not forget to change the value of that property to intellij_idea. When not set, this is still the default code style of ktlint 0.49. Note that the default code style will be changed to ktlint_official in the 1.0 release.

Code style android has been renamed to android_studio. Code formatted with this code style aims to be compatible with default formatter of Android Studio. This code style is based on Android's Kotlin styleguide. If .editorconfig property ktlint_code_style has been set to android then do not forget to change the value of that property to android_studio.

Package restructuring and class relocation

The internal structure of the Ktlint project has been revised. The Ktlint CLI and KtLint API modules have been decoupled where possible. Modules have been restructured and renamed. See API Overview for more information.

This is the last release that contains module ktlint-core as it had too many responsibilities. All classes in this module are relocated to other modules. Some classes have also been renamed. See tables below for details. Classes that are left behind in the ktlint-core module are deprecated and were kept in this version for backwards compatibility only. The ktlint-core module will be removed in Ktlint 0.50.x.

Classes below have been moved from module ktlint-core to the new module ktlint-rule-engine-core:

Old class/package name in `ktlint-core`	New class/package name in `ktlint-rule-engine-core`
com.pinterest.ktlint.core.api.editorconfig	com.pinterest.ktlint.rule.engine.core.api.editorconfig
com.pinterest.ktlint.core.api.EditorConfigProperties	com.pinterest.ktlint.rule.engine.core.api.EditorConfig
com.pinterest.ktlint.core.api.OptInFeatures	com.pinterest.ktlint.rule.engine.core.api.OptInFeatures
com.pinterest.ktlint.core.ast.ElementType	com.pinterest.ktlint.rule.engine.core.api.ElementType
com.pinterest.ktlint.core.ast.package	com.pinterest.ktlint.rule.engine.core.api.ASTNodeExtension
com.pinterest.ktlint.core.IndentConfig	com.pinterest.ktlint.rule.engine.core.api.IndentConfig
com.pinterest.ktlint.core.Rule	com.pinterest.ktlint.rule.engine.core.api.Rule
com.pinterest.ktlint.core.RuleProvider	com.pinterest.ktlint.rule.engine.core.api.RuleProvider

Classes below have been moved from module ktlint-core to the new module ktlint-rule-engine:

Old class/package name in `ktlint-core`	New class/package name in `ktlint-rule-engine`
com.pinterest.ktlint.core.api.EditorConfigDefaults	com.pinterest.ktlint.rule.engine.api.EditorConfigDefaults
com.pinterest.ktlint.core.api.EditorConfigOverride	com.pinterest.ktlint.rule.engine.api.EditorConfigOverride
com.pinterest.ktlint.core.api.KtLintParseException	com.pinterest.ktlint.rule.engine.api.KtLintParseException
com.pinterest.ktlint.core.api.KtLintRuleException	com.pinterest.ktlint.rule.engine.api.KtLintRuleException
com.pinterest.ktlint.core.KtLint	com.pinterest.ktlint.rule.engine.api.KtLintRuleEngine
com.pinterest.ktlint.core.LintError	com.pinterest.ktlint.rule.engine.api.LintError

Class com.pinterest.ktlint.core.KtLint.Code.CodeFile has been replaced with factory method com.pinterest.ktlint.rule.engine.api.Code.fromFile. Likewise, class com.pinterest.ktlint.core.KtLint.Code.CodeSnippet has been replaced with factory method com.pinterest.ktlint.rule.engine.api.Code.fromSnippet.

Class below has been moved from module ktlint-core to the new module ktlint-cli-ruleset-core:

Old class/package name in `ktlint-core`	New class/package name in `ktlint-cli-ruleset-core`
com.pinterest.ktlint.core.RuleSetProviderV2	com.pinterest.ktlint.cli.ruleset.core.api.RuleSetProviderV3

Class below has been moved from module ktlint-core to the new module ktlint-cli-reporter-core:

Old class/package name in `ktlint-core`	New class/package name in `ktlint-cli-reporter-core`
com.pinterest.ktlint.core.KtlintVersion	com.pinterest.ktlint.cli.reporter.core.api.KtlintVersion

Class below has been moved from module ktlint-core to the new module ktlint-logger:

Old class/package name in `ktlint-core`	New class/package name in `ktlint-logger`
com.pinterest.ktlint.core.KtLintKLoggerInitializer.kt	com.pinterest.ktlint.logger.api.KtLintKLoggerInitializer.kt

Class below has been relocated from module ktlint-core to module ktlint-cli:

Old class/package name in `ktlint-core`	New class/package name in `ktlint-cli`
com.pinterest.ktlint.core.api.Baseline	com.pinterest.ktlint.cli.api.Baseline

Module ktlint-reporter-baseline has been renamed to ktlint-cli-reporter-baseline. Class below has been relocated:

Old class/package name in `ktlint-reporter-baseline`	New class/package name in `ktlint-cli-reporter-baseline`
com.pinterest.ktlint.reporter.baseline	com.pinterest.ktlint.cli.reporter.baseline

Module ktlint-reporter-checkstyle has been renamed to ktlint-cli-reporter-checkstyle. Class below has been relocated:

Old class/package name in `ktlint-reporter-checkstyle`	New class/package name in `ktlint-cli-reporter-checkstyle`
com.pinterest.ktlint.reporter.checkstyle	com.pinterest.ktlint.cli.reporter.checkstyle

Module ktlint-reporter-format has been renamed to ktlint-cli-reporter-format. Class below has been relocated:

Old class/package name in `ktlint-reporter-format`	New class/package name in `ktlint-cli-reporter-format`
com.pinterest.ktlint.reporter.format	com.pinterest.ktlint.cli.reporter.format

Module ktlint-reporter-html has been renamed to ktlint-cli-reporter-html. Class below has been relocated:

Old class/package name in `ktlint-reporter-html`	New class/package name in `ktlint-cli-reporter-html`
com.pinterest.ktlint.reporter.html	com.pinterest.ktlint.cli.reporter.html

Module ktlint-reporter-json has been renamed to ktlint-cli-reporter-json. Class below has been relocated:

Old class/package name in `ktlint-reporter-json`	New class/package name in `ktlint-cli-reporter-json`
com.pinterest.ktlint.reporter.json	com.pinterest.ktlint.cli.reporter.json

Module ktlint-reporter-plain has been renamed to ktlint-cli-reporter-plain. Class below has been relocated:

Old class/package name in `ktlint-reporter-plain`	New class/package name in `ktlint-cli-reporter-plain`
com.pinterest.ktlint.reporter.plain	com.pinterest.ktlint.cli.reporter.plain

Module ktlint-reporter-plain-summary has been renamed to ktlint-cli-reporter-plain-summary. Class below has been relocated:

Old class/package name in `ktlint-reporter-plain-summary`	New class/package name in `ktlint-cli-reporter-plain-summary`
com.pinterest.ktlint.reporter.plain	com.pinterest.ktlint.cli.reporter.plainsummary

Module ktlint-reporter-sarif has been renamed to ktlint-cli-reporter-sarif. Class below has been relocated:

Old class/package name in `ktlint-reporter-sarif`	New class/package name in `ktlint-cli-reporter-sarif`
com.pinterest.ktlint.reporter.sarif	com.pinterest.ktlint.cli.reporter.sarif

Custom Ruleset Provider `RuleSetProviderV2`

Custom rule sets build for older versions of KtLint are no longer supported by this version of KtLint. The com.pinterest.ktlint.core.RuleSetProviderV2 interface has been replaced with RuleSetProviderV3. The accompanying interfaces com.pinterest.ktlint.core.RuleProvider and com.pinterest.ktlint.core.Rule have been replaced with com.pinterest.ktlint.ruleset.core.api.RuleProvider and com.pinterest.ktlint.ruleset.core.api.Rule respectively.

Contrary to RuleSetProviderV2, the RuleSetProviderV3 no longer contains information about the rule set. About information now has to be specified in the new Rule class. This allows custom rule set providers to combine rules originating from different rule sets into a new rule set without loosing information about its origin. The type of the id of the rule set is changed from String to RuleSetId.

Note that due to renaming and relocation of the RuleSetProviderV3 interface the name of the service provider in the custom reporter needs to be changed from resources/META-INF/services/com.pinterest.ktlint.core.RuleSetProviderV2 to resources/META-INF/services/com.pinterest.ktlint.cli.ruleset.core.api.RuleSetProviderV3.

The rule id's in com.pinterest.ktlint.ruleset.core.api.Rule have been changed from type String to RuleId. A RuleId has a value that must adhere the convention "rule-set-id:rule-id". The rule set id standard is reserved for rules which are maintained by the KtLint project. Rules created by custom rule set providers and API Consumers should use a prefix other than standard to mark the origin of rules which are not maintained by the KtLint project.

When wrapping a rule from the ktlint project and modifying its behavior, please change the ruleId and about fields in the wrapped rule, so that it is clear to users whenever they use the original rule provided by KtLint versus a modified version which is not maintained by the KtLint project.

The typealias com.pinterest.ktlint.core.api.EditorConfigProperties has been replaced with com.pinterest.ktlint.rule.engine.core.api.EditorConfig. The interface com.pinterest.ktlint.core.api.UsesEditorConfigProperties has been removed. Instead, the Rule property usesEditorConfigProperties needs to be set. As a result of those changes, the beforeFirstNode function in each rule has to changed to something like below:

 class SomeRule : Rule(
  ruleId = RuleId("some-rule-set:some-rule"),
  usesEditorConfigProperties = setOf(MY_EDITOR_CONFIG_PROPERTY),
) {
  private lateinit var myEditorConfigProperty: MyEditorConfigProperty

  override fun beforeFirstNode(editorConfig: EditorConfig) {
    myEditorConfigProperty = editorConfig[MY_EDITOR_CONFIG_PROPERTY]
  }
  
  ...
}

Fields loadOnlyWhenOtherRuleIsLoaded and runOnlyWhenOtherRuleIsEnabled have been removed from class com.pinterest.ktlint.rule.engine.core.api.Rule.VisitorModifier.RunAfterRule and are replaced with a single field mode. The mode either contains value REGARDLESS_WHETHER_RUN_AFTER_RULE_IS_LOADED_OR_DISABLED or ONLY_WHEN_RUN_AFTER_RULE_IS_LOADED_AND_ENABLED.

Custom Reporter Provider `ReporterProvider`

Custom Reporters build for older versions of KtLint are no longer supported by this version of KtLint. The com.pinterest.ktlint.core.ReporterProvider interface has been replaced with com.pinterest.ktlint.cli.reporter.core.api.ReporterProviderV2. The accompanying interface com.pinterest.ktlint.core.Reporter has been replaced with com.pinterest.ktlint.cli.reporter.core.api.ReporterV2.

Note that due to renaming and relocation of the ReporterProviderV2 interface the name of the service provider in the custom reporter needs to be changed from resources/META-INF/services/com.pinterest.ktlint.core.ReporterProvider to resources/META-INF/services/com.pinterest.ktlint.cli.reporter.core.api.ReporterProviderV2.

The biggest change in the ReporterV2 is the replacement of the LintError class with KtlintCliError class. The latter class now contains a status field which more clearly explains the difference between a lint error which can be autocorrected versus a lint error that actually has been autocorrected.

Custom rules provided by API Consumer

API Consumers provide a set of rules directly to the Ktlint Rule Engine. The com.pinterest.ktlint.core.Rule has been replaced with com.pinterest.ktlint.ruleset.core.api.Rule.

The type of the rule id's has been changed from type String to RuleId. A RuleId has a value that must adhere to the convention "rule-set-id:rule-id". Rule set id standard is reserved for rules which are maintained by the KtLint project. Custom rules created by the API Consumer should use a prefix other than standard to clearly mark the origin of rules which are not maintained by the KtLint project.

Also, the field About has been added. This field specifies the name of the maintainer, and the repository url and issue tracker url of the rule. The about information of a rule is printed whenever a rule throws an exception which is caught by the Ktlint Rule Engine.

When wrapping a rule from the ktlint project and modifying its behavior, please change the ruleId and about fields in the wrapped rule, so that it is clear to users whenever they use the original rule provided by KtLint versus a modified version which is not maintained by the KtLint project.

The typealias com.pinterest.ktlint.core.api.EditorConfigProperties has been replaced with com.pinterest.ktlint.rule.engine.core.api.EditorConfig. The interface com.pinterest.ktlint.core.api.UsesEditorConfigProperties has been removed. Instead, the Rule property usesEditorConfigProperties needs to be set. As a result of those changes, the beforeFirstNode function in each rule has to changed to something like below:

 class SomeRule : Rule(
  ruleId = RuleId("some-rule-set:some-rule"),
  usesEditorConfigProperties = setOf(MY_EDITOR_CONFIG_PROPERTY),
) {
  private lateinit var myEditorConfigProperty: MyEditorConfigProperty

  override fun beforeFirstNode(editorConfig: EditorConfig) {
    myEditorConfigProperty = editorConfig[MY_EDITOR_CONFIG_PROPERTY]
  }

  ...
}

Fields loadOnlyWhenOtherRuleIsLoaded and runOnlyWhenOtherRuleIsEnabled have been removed from class com.pinterest.ktlint.rule.engine.core.api.Rule.VisitorModifier.RunAfterRule and are replaced with a single field mode. The mode either contains value REGARDLESS_WHETHER_RUN_AFTER_RULE_IS_LOADED_OR_DISABLED or ONLY_WHEN_RUN_AFTER_RULE_IS_LOADED_AND_ENABLED.

Like before, the API Consumer can still offer a mix of rules originating from ktlint-ruleset-standard as well as custom rules.

`.editorconfig` property `max_line_length` default value

Previously, the default value for .editorconfig property max_line_length was set to -1 in ktlint unless the property was defined explicitly in the .editorconfig or when ktlint_code_style was set to Android. As a result of that rules have to check that max_line_length contains a positive value before checking that the actual line length is exceeding the maximum. Now the value Int.MAX_VALUE (use constant MAX_LINE_LENGTH_PROPERTY_OFF to refer to that value) is used instead.

Psi filename replaces FILE_PATH_USER_DATA_KEY

Constant KtLint.FILE_PATH_USER_DATA_KEY has been removed. The file path is passed correctly to the node with element type FILE and can be retrieved as follows:

if (node.isRoot()) {
  val filePath = (node.psi as? KtFile)?.virtualFilePath
    ...
}

Added

Add new code style ktlint_offical. The code style is work in progress and should be considered a preview. It is intended to become the default code style in the next release. Please try it out and give your feedback. See code styles for more information. The following rules have been added to the ktlint_official code style (the rules can also be run for other code styles when enabled explicitly):
- Add new experimental rule no-empty-first-line-in-class-body. This rule disallows a class to start with a blank line.
- Add new experimental rule if-else-bracing. This rules enforces consistent usage of braces in all branches of a single if, if-else or if-else-if statement.
- Add new experimental rule no-consecutive-comments. This rule disallows consecutive comments except EOL comments (see [examples](See https://pinterest.github.io/ktlint/rules/experimental/#disallow-consecutive-comments)).
- Add new experimental rule try-catch-finally-spacing. This rule enforces consistent spacing in try-catch, try-finally and try-catch-finally statement. This rule can also be run for other code styles, but then it needs to be enabled explicitly.
- Add new experimental rule no-blank-line-in-list. This rule disallows blank lines to be used in super type lists, type argument lists, type constraint lists, type parameter lists, value argument lists, and value parameter lists. (#1224)
- Add new experimental rule multiline-expression-wrapping. This forces a multiline expression as value in an assignment to start on a separate line. (#1217)
- Add new experimental rule string-template-indent. This forces multiline string templates which are post-fixed with .trimIndent() to be formatted consistently. The opening and closing """ are placed on separate lines and the indentation of the content of the template is aligned with the """. (#925)
- Add new experimental rule if-else-wrapping. This enforces that a single line if-statement is kept simple. A single line if-statement may contain no more than one else-branch. The branches a single line if-statement may not be wrapped in a block. (#812)
Wrap the type or value of a function or class parameter in case the maximum line length is exceeded parameter-wrapping (#1846)
Wrap the type or value of a property in case the maximum line length is exceeded property-wrapping (#1846)
Recognize Kotlin Script when linting and formatting code from stdin with KtLint CLI (#1832)

Support Bill of Materials (BOM), now you can integrate Ktlint in your build.gradle like:

dependencies {
    implementation(platform("com.pinterest:ktlint-bom:0.49.0"))
    implementation("com.pinterest:ktlint-core")
    implementation("com.pinterest:ktlint-reporter-html")
    implementation("com.pinterest:ktlint-ruleset-standard")
    ...
}

Add new experimental rule enum-wrapping for all code styles. An enum should either be a single line, or each enum entry should be defined on a separate line. (#1903)

Removed

Remove support of the .editorconfig properties disabled_rules and ktlint_disabled_rules. See disabled rules for more information.
Remove CLI option --print-ast. Use IntelliJ IDEA PsiViewer plugin instead. (#1925)

Fixed

An enumeration class having a primary constructor and in which the list of enum entries is followed by a semicolon then do not remove the semicolon in case it is followed by code element no-semi (#1733)
Do not add the (first line of the) body expression on the same line as the function signature in case the max line length would be exceeded. function-signature.
Do not add the first line of a multiline body expression on the same line as the function signature in case function body expression wrapping property is set to multiline. function-signature.
Disable the standard:filename rule whenever Ktlint CLI is run with option --stdin (#1742)
The parameters of a function literal containing a multiline parameter list are aligned with first parameter whenever the first parameter is on the same line as the start of that function literal (not allowed in ktlint_official code style) indent (#1756)
Do not throw exception when enum class does not contain entries trailing-comma-on-declaration-site (#1711)
Fix continuation indent for a dot qualified array access expression in ktlint_official code style only indent (#1540)
When generating the .editorconfig use value off for the max_line_length property instead of value -1 to denote that lines are not restricted to a maximum length (#1824)
Do not report an "unnecessary semicolon" after adding a trailing comma to an enum class containing a code element after the last enum entry trailing-comma-on-declaration-site (#1786)
A newline before a function return type should not be removed in case that leads to exceeding the maximum line length function-return-type-spacing (#1764)
Wrap annotations on type arguments in same way as with other constructs annotation, wrapping (#1725)
Fix indentation of try-catch-finally when catch or finally starts on a newline indent (#1788)
Fix indentation of a multiline typealias indent (#1788)
Fix false positive when multiple KDOCs exists between a declaration and another annotated declaration spacing-between-declarations-with-annotations (#1802)
Fix false positive when a single line statement containing a block having exactly the maximum line length is preceded by a blank line wrapping (#1808)
Fix false positive when a single line contains multiple dot qualified expressions and/or safe expressions indent (#1830)
Enforce spacing around rangeUntil operator ..< similar to the range operator .. in range-spacing (#1858)
When .editorconfig property ij_kotlin_imports_layout contains a | but no import exists that match any pattern before the first | then do not report a violation nor insert a blank line import-ordering (#1845)
When negate-patterns only are specified in Ktlint CLI then automatically add the default include patterns (**/*.kt and **/*.kts) so that all Kotlin files excluding the files matching the negate-patterns will be processed (#1847)
Do not remove newlines from multiline type parameter lists type-parameter-list-spacing (#1867)
Wrap each type parameter in a multiline type parameter list wrapping (#1867)
Allow value arguments with a multiline expression to be indented on a separate line indent (#1217)
When enabled, the ktlint rule checking is disabled for all code surrounded by the formatter tags (see faq) (#670)
Remove trailing comma if last two enum entries are on the same line and trailing commas are not allowed. trailing-comma-on-declaration-site (#1905)
Wrap annotated function parameters to a separate line in code style ktlint_official only. function-signature, parameter-list-wrapping (#1908)
Wrap annotated projection types in type argument lists to a separate line annotation (#1909)
Add newline after adding trailing comma in parameter list of a function literal trailing-comma-on-declaration-site (#1911)
Wrap annotations before class constructor in code style ktlint_official. annotation (#1916)
Annotations on type projections should be wrapped in same way as other annotations annotation (#1917)
An if-else followed by an elvis operator should not be wrapped in an else-block multiline-if-else (#1904)

Changed

Wrap the parameters of a function literal containing a multiline parameter list (only in ktlint_official code style) parameter-list-wrapping (#1681).
KtLint CLI exits with an error in any of following cases (this list is not exhaustive):
- A custom ruleset jar is to be loaded and that jar contains a deprecated RuleSetProviderV2.
- A custom ruleset jar is to be loaded and that jar does not contain the required RuleSetProviderV3.
- A custom reporter jar is to be loaded and that jar contains a deprecated ReporterProvider.
- A custom reporter jar is to be loaded and that jar does not contain the required ReporterProviderV2.
Disable the default patterns if the option --patterns-from-stdin is specified (#1793)
Update Kotlin development version to 1.8.20 and Kotlin version to 1.8.20.
Revert to matrix build to speed up build, especially for the Windows related build (#1787)
For the new code style ktlint_official, do not allow wildcard imports java.util and kotlinx.android.synthetic by default. Important: .editorconfig property ij_kotlin_packages_to_use_import_on_demand needs to be set to value unset in order to enforce IntelliJ IDEA default formatter to not generate wildcard imports no-wildcard-imports (#1797)
Convert a single line block comment to an EOL comment if not preceded or followed by another code element on the same line comment-wrapping (#1941)
Ignore a block comment inside a single line block comment-wrapping (#1942)

0.48.2 - 2023-01-21

Additional clarification on API Changes in `0.48.0` and `0.48.1`

Starting with Ktlint 0.48.x, rule and rule sets can be enabled/disabled with a separate property per rule (set). Please read deprecation of (ktlint_)disable_rules property for more information.

API Consumers that provide experimental rules to the KtLintRuleEngine, must also enable the experimental rules or instruct their users to do so in the .editorconfig file. From the perspective of the API Consumer it might be confusing or unnecessary to do so as the experimental rule was already provided explicitly.

Ktlint wants to provide the user (e.g. a developer) a uniform and consistent user experience. The .editorconfig becomes more and more central to store configuration for Ktlint. This to ensure that all team members use the exact same configuration when running ktlint regardless whether the Ktlint CLI or an API Consumer is being used.

The .editorconfig is a powerful configuration tool which can be used in very different ways. Most projects use a single .editorconfig file containing one common section for kotlin and kotlin scripts files. For example, the .editorconfig file of the Ktlint project contains following section:

[*.{kt,kts}]
ij_kotlin_imports_layout = *
ij_kotlin_allow_trailing_comma = true
ij_kotlin_allow_trailing_comma_on_call_site = true

Other projects might contain multiple .editorconfig files for different parts of the project directory hierarchy. Or, use a single .editorconfig file containing multiple sections with different globs. Like all other configuration settings in Ktlint, the user should be able to enable and disable the experimental rules. Both for the entire set of experimental rules and for individual experimental rules.

Ktlint allows API Consumers to set default values and override values for the .editorconfig. Specifying a default value means that the user does not need to define the property in the .editorconfig file but if the user specifies the value, it will take precedence. Specifying the override value ensures that this takes precedence on a value specified by the user in the .editorconfig.

From the Ktlint perspective, it is advised that API Consumers provide the default value. See example below, for how to specify the editorConfigDefault property:

KtLintRuleEngine(
    ruleProviders = ruleProviders,
    editorConfigDefaults = EditorConfigDefaults(
        EditorConfig
            .builder()
            .section(
                Section
                    .builder()
                    .glob(Glob("*.{kt,kts}"))
                    .properties(
                        Property
                            .builder()
                            .name("ktlint_experimental")
                            .value("enabled"),
                    ),
            )
            .build()
    )
)

If the user has set property ktlint_experimental explicitly than that value will be used. If the value is not defined, the value provided via editorConfigDefaults will be used.

If you do want to ignore the value of ktlint_experimental as set by the user, than you can set the EditorConfigOverride property. But as said before that is discouraged as the user might not understand why the .editorconfig property is being ignored (provided that the value set is not equal to the value provided by the API Consumer).

Added

Removed

Fixed

Fix with array-syntax annotations on the same line as other annotations annotation (#1765)
Do not enable the experimental rules by default when .editorconfig properties disabled_rules or ktlint_disabled_rules are set. (#1771)
A function signature not having any parameters which exceeds the max-line-length should be ignored by rule function-signature (#1773)
Allow diacritics in names of classes, functions packages, and properties class-naming, function-naming, package-name, property-naming (#1757)
Prevent violation of file-name rule on code snippets (#1768)
Clarify that API Consumers have to enable experimental rules (#1768)
Trim spaces in the .editorconfig property ij_kotlin_imports_layout's entries (#1770)

Changed

0.48.1 - 2023-01-03

Added

Removed

Fixed

An enumeration class having a primary constructor and in which the list of enum entries is followed by a semicolon then do not remove the semicolon in case it is followed by code element no-semi (#1733)
Add API so that KtLint API consumer is able to process a Kotlin script snippet without having to specify a file path (#1738)
Disable the standard:filename rule whenever Ktlint CLI is run with option --stdin (#1742)
Fix initialization of the logger when --log-level is specified. Throw exception when an invalid value is passed. (#1749)
Fix loading of custom rule set JARs.
Rules provided via a custom rule set JAR (Ktlint CLI) or by an API provider are enabled by default. Only rules in the experimental rule set are disabled by default. (#1747)

Changed

Update Kotlin development version to 1.8.0 and Kotlin version to 1.8.0.

0.48.0 - 2022-12-15

Indent rule

The indent rule has been rewritten from scratch. Solving problems in the old algorithm was very difficult. With the new algorithm this becomes a lot easier. Although the new implementation of the rule has been compared against several open source projects containing over 400,000 lines of code, it is still likely that new issues will be discovered. Please report your indentation issues so that these can be fixed as well.

`.editorconfig` property to disable rules

In the previous release (0.47.x), the .editorconfig property disabled_rules was deprecated and replaced with ktlint_disabled_rules. This latter property has now been deprecated as well in favour of a more flexible and better maintainable solution. Rule and rule sets can now be enabled/disabled with a separate property per rule (set). Please read deprecation of (ktlint_)disable_rules property for more information.

The KtLint CLI has not been changed. Although you can still use parameter --experimental to enable KtLint's Experimental rule set, you might want to set .editorconfig property ktlint_experimental = enabled instead.

API Changes & RuleSet providers

If you are not an API consumer or Rule Set provider then you can skip this section.

Class relocations

Classes below have been relocated:

Class com.pinterest.ktlint.core.api.UsesEditorConfigProperties.EditorConfigProperty has been replaced with com.pinterest.ktlint.core.api.editorconfig.EditorConfigProperty.
Class com.pinterest.ktlint.core.KtLintParseException has been replaced with com.pinterest.ktlint.core.api.KtLintParseException.
Class com.pinterest.ktlint.core.RuleExecutionException has been replaced with com.pinterest.ktlint.core.api.KtLintRuleException.
Class com.pinterest.ktlint.reporter.format.internal.Color has been moved to com.pinterest.ktlint.reporter.format.Color.
Class com.pinterest.ktlint.reporter.plain.internal.Color has been moved to com.pinterest.ktlint.reporter.plain.Color.

Invoking `lint` and `format`

This is the last release that supports the ExperimentalParams to invoke the lint and format functions of KtLint. The ExperimentalParams contains a mix of configuration settings which are not dependent on the file/code which is to be processed. Other parameters in that class describe the code/file to be processed but can be configured inconsistently (for example a file with name "foo.kt" could be marked as a Kotlin Script file).

The static object KtLint is deprecated and replaced by class KtLintRuleEngine which is configured with KtLintRuleEngineConfiguration. The instance of the KtLintRuleEngine is intended to be reused for scanning all files in a project and should not be recreated per file.

Both lint and format are simplified and can now be called for a code block or for an entire file.

import java.io.File

// Define a reusable instance of the KtLint Rule Engine
val ktLintRuleEngine = KtLintRuleEngine(
  // Define configuration
)


// Process a collection of files
val files: Set<File> // Collect files in a convenient way
files.forEach(file in files) {
    ktLintRuleEngine.lint(file) {
        // Handle lint violations
    }
}

// or process a code sample for a given filepath
ktLintRuleEngine.lint(
  code = "code to be linted",
  filePath = Path("/path/to/source/file")
) {
  // Handle lint violations
}

Retrieve `.editorconfig`s

The list of .editorconfig files which will be accessed by KtLint when linting or formatting a given path can now be retrieved with the new API KtLint.editorConfigFilePaths(path: Path): List<Path>.

This API can be called with either a file or a directory. It's intended usage is that it is called once with the root directory of a project before actually linting or formatting files of that project. When called with a directory path, all .editorconfig files in the directory or any of its subdirectories (except hidden directories) are returned. In case the given directory does not contain an .editorconfig file or if it does not contain the root=true setting, the parent directories are scanned as well until a root .editorconfig file is found.

Calling this API with a file path results in the .editorconfig files that will be accessed when processing that specific file. In case the directory in which the file resides does not contain an .editorconfig file or if it does not contain the root=true setting, the parent directories are scanned until a root .editorconfig file is found.

Psi filename replaces FILE_PATH_USER_DATA_KEY

Constant KtLint.FILE_PATH_USER_DATA_KEY is deprecated and will be removed in KtLint version 0.49.0. The file name will be passed correctly to the node with element type FILE and can be retrieved as follows:

if (node.isRoot()) {
    val fileName = (node.psi as? KtFile)?.name
    ...
}

Added

Wrap blocks in case the max line length is exceeded or in case the block contains a new line wrapping (#1643)
patterns can be read in from stdin with the --patterns-from-stdin command line options/flags (#1606)
Add basic formatting for context receiver in indent rule and new experimental rule context-receiver-wrapping (#1672)
Add naming rules for classes and objects (class-naming), functions (function-naming) and properties (property-naming) (#44)
Add new built-in reporter plain-summary which prints a summary the number of violation which have been autocorrected or could not be autocorrected, both split by rule.

Fixed

Let a rule process all nodes even in case the rule is suppressed for a node so that the rule can update the internal state (#1644)
Read .editorconfig when running CLI with options --stdin and --editorconfig (#1651)
Do not add a trailing comma in case a multiline function call argument is found but no newline between the arguments trailing-comma-on-call-site (#1642)
Add missing ktlint_disabled_rules to exposed editorConfigProperties (#1671)
Do not add a second trailing comma, if the original trailing comma is followed by a KDOC trailing-comma-on-declaration-site and trailing-comma-on-call-site (#1676)
A function signature preceded by an annotation array should be handled similar as function preceded by a singular annotation function-signature (#1690)
Fix offset of annotation violations
Fix line offset when blank line found between class and primary constructor
Remove needless blank line between class followed by EOL, and primary constructor
Fix offset of unexpected linebreak before assignment
Remove whitespace before redundant semicolon if the semicolon is followed by whitespace

Changed

Update Kotlin development version to 1.8.0-RC and Kotlin version to 1.7.21.
The default value for trailing commas on call site is changed to true unless the android codestyle is enabled. Note that KtLint from a consistency viewpoint enforces the trailing comma on call site while default IntelliJ IDEA formatting only allows the trailing comma but leaves it up to the developer's discretion. (#1670)
The default value for trailing commas on declaration site is changed to true unless the android codestyle is enabled. Note that KtLint from a consistency viewpoint enforces the trailing comma on declaration site while default IntelliJ IDEA formatting only allows the trailing comma but leaves it up to the developer's discretion. (#1669)
CLI options --debug, --trace, --verbose and -v are replaced with --log-level=<level> or the short version `-l=, see CLI log-level. (#1632)
In CLI, disable logging entirely by setting --log-level=none or -l=none (#1652)
Rewrite indent rule. Solving problems in the old algorithm was very difficult. With the new algorithm this becomes a lot easier. Although the new implementation of the rule has been compared against several open source projects containing over 400,000 lines of code, it is still likely that new issues will be discovered. Please report your indentation issues so that these can be fixed as well. (#1682, #1321, #1200, #1562, #1563, #1639)
Add methods "ASTNode.upsertWhitespaceBeforeMe" and "ASTNode.upsertWhitespaceAfterMe" as replacements for "LeafElement.upsertWhitespaceBeforeMe" and "LeafElement.upsertWhitespaceAfterMe". The new methods are more versatile and allow code to be written more readable in most places. (#1687)
Rewrite indent rule. Solving problems in the old algorithm was very difficult. With the new algorithm this becomes a lot easier. Although the new implementation of the rule has been compared against several open source projects containing over 400,000 lines of code, it is still likely that new issues will be discovered. Please report your indentation issues so that these can be fixed as well. (#1682, #1321, #1200, #1562, #1563, #1639, #1688)
Add support for running tests on java 19, remove support for running tests on java 18.
Update io.github.detekt.sarif4k:sarif4k version to 0.2.0 (#1701).

0.47.1 - 2022-09-07

Fixed

Do not add trailing comma in empty parameter/argument list with comments (trailing-comma-on-call-site, trailing-comma-on-declaration-site) (#1602)
Fix class cast exception when specifying a non-string editorconfig setting in the default ".editorconfig" (#1627)
Fix indentation before semi-colon when it is pushed down after inserting a trailing comma (#1609)
Do not show deprecation warning about property "disabled_rules" when using CLi-parameter --disabled-rules (#1599)
Traversing directory hierarchy at Windows (#1600)
Ant-style path pattern support (#1601)
Apply @file:Suppress on all toplevel declarations (#1623)

Changed

Display warning instead of error when no files are matched, and return with exit code 0. (#1624)

0.47.0 - 2022-08-19

API Changes & RuleSet providers

If you are not an API consumer nor a RuleSet provider, then you can safely skip this section. Otherwise, please read below carefully and upgrade your usage of ktlint. In this and coming releases, we are changing and adapting important parts of our API in order to increase maintainability and flexibility for future changes. Please avoid skipping a releases as that will make it harder to migrate.

Rule lifecycle hooks / deprecate RunOnRootOnly visitor modifier

Up until ktlint 0.46 the Rule class provided only one life cycle hook. This "visit" hook was called in a depth-first-approach on all nodes in the file. A rule like the IndentationRule used the RunOnRootOnly visitor modifier to call this lifecycle hook for the root node only in combination with an alternative way of traversing the ASTNodes. Downside of this approach was that suppression of the rule on blocks inside a file was not possible (#631). More generically, this applied to all rules, applying alternative traversals of the AST.

The Rule class now offers new life cycle hooks:

beforeFirstNode: This method is called once before the first node is visited. It can be used to initialize the state of the rule before processing of nodes starts. The ".editorconfig" properties (including overrides) are provided as parameter.
beforeVisitChildNodes: This method is called on a node in AST before visiting its child nodes. This is repeated recursively for the child nodes resulting in a depth first traversal of the AST. This method is the equivalent of the "visit" life cycle hooks. However, note that in KtLint 0.48, the UserData of the rootnode no longer provides access to the ".editorconfig" properties. This method can be used to emit Lint Violations and to autocorrect if applicable.
afterVisitChildNodes: This method is called on a node in AST after all its child nodes have been visited. This method can be used to emit Lint Violations and to autocorrect if applicable.
afterLastNode: This method is called once after the last node in the AST is visited. It can be used for teardown of the state of the rule.

Optionally, a rule can stop the traversal of the remainder of the AST whenever the goal of the rule has been achieved. See KDoc on Rule class for more information.

The "visit" life cycle hook will be removed in Ktlint 0.48. In KtLint 0.47 the "visit" life cycle hook will be called only when hook "beforeVisitChildNodes" is not overridden. It is recommended to migrate to the new lifecycle hooks in KtLint 0.47. Please create an issue, in case you need additional assistence to implement the new life cycle hooks in your rules.

Ruleset providing by Custom Rule Set Provider

The KtLint engine needs a more fine-grained control on the instantiation of new Rule instances. Currently, a new instance of a rule can be created only once per file. However, when formatting files the same rule instance is reused for a second processing iteration in case a Lint violation has been autocorrected. By re-using the same rule instance, state of that rule might leak from the first to the second processing iteration.

Providers of custom rule sets have to migrate the custom rule set JAR file. The current RuleSetProvider interface which is implemented in the custom rule set is deprecated and marked for removal in KtLint 0.48. Custom rule sets using the old RuleSetProvider interface will not be run in KtLint 0.48 or above.

For now, it is advised to implement the new RuleSetProviderV2 interface without removing the old RuleSetProvider interface. In this way, KtLint 0.47 and above use the RuleSetProviderV2 interface and ignore the old RuleSetProvider interface completely. KtLint 0.46 and below only use the old RuleSetProvider interface.

Adding the new interface is straight forward, as can be seen below:

// Current implementation
public class CustomRuleSetProvider : RuleSetProvider {
    override fun get(): RuleSet = RuleSet(
        "custom",
        CustomRule1(),
        CustomRule2(),
    )
}

// New implementation
public class CustomRuleSetProvider :
    RuleSetProviderV2(CUSTOM_RULE_SET_ID),
    RuleSetProvider {
    override fun get(): RuleSet =
        RuleSet(
            CUSTOM_RULE_SET_ID,
            CustomRule1(),
            CustomRule2()
        )

    override fun getRuleProviders(): Set<RuleProvider> =
        setOf(
            RuleProvider { CustomRule1() },
            RuleProvider { CustomRule2() }
        )

    private companion object {
        const val CUSTOM_RULE_SET_ID = custom"
    }
}

Also note that file 'resource/META-INF/services/com.pinterest.ktlint.core.RuleSetProviderV2' needs to be added. In case your custom rule set provider implements both RuleSetProvider and RuleSetProviderV2, the resource directory contains files for both implementation. The content of those files is identical as the interfaces are implemented on the same class.

Once above has been implemented, rules no longer have to clean up their internal state as the KtLint rule engine can request a new instance of the Rule at any time it suspects that the internal state of the Rule is tampered with (e.g. as soon as the Rule instance is used for traversing the AST).

Rule set providing by API Consumer

The KtLint engine needs a more fine-grained control on the instantiation of new Rule instances. Currently, a new instance of a rule can be created only once per file. However, when formatting files the same rule instance is reused for a second processing iteration in case a Lint violation has been autocorrected. By re-using the same rule instance, state of that rule might leak from the first to the second processing iteration.

The ExperimentalParams parameter which is used to invoke "KtLint.lint" and "KtLint.format" contains a new parameter "ruleProviders" which will replace the "ruleSets" parameter in KtLint 0.48. Exactly one of those parameters should be a non-empty set. It is preferred that API consumers migrate to using "ruleProviders".

// Old style using "ruleSets"
KtLint.format(
    KtLint.ExperimentalParams(
        ...
        ruleSets = listOf(
            RuleSet(
                "custom",
                CustomRule1(),
                CustomRule2()
            )
        ),
        ...
    )
)

// New style using "ruleProviders"
KtLint.format(
    KtLint.ExperimentalParams(
        ...
        ruleProviders = setOf(
            RuleProvider { CustomRule1() },
            RuleProvider { CustomRule2() }
        ),
        cb = { _, _ -> }
    )
)

Once above has been implemented, rules no longer have to clean up their internal state as the KtLint rule engine can request a new instance of the Rule at any time it suspects that the internal state of the Rule is tampered with (e.g. as soon as the Rule instance is used for traversing the AST).

Format callback

The callback function provided as parameter to the format function is now called for all errors regardless whether the error has been autocorrected. Existing consumers of the format function should now explicitly check the autocorrected flag in the callback result and handle it appropriately (in most case this will be ignoring the callback results for which autocorrected has value true).

CurrentBaseline

Class com.pinterest.ktlint.core.internal.CurrentBaseline has been replaced with com.pinterest.ktlint.core.api.Baseline.

Noteworthy changes:

Field baselineRules (nullable) is replaced with `lintErrorsPerFile (non-nullable).
Field baselineGenerationNeeded (boolean) is replaced with status (type Baseline.Status).

The utility functions provided via com.pinterest.ktlint.core.internal.CurrentBaseline are moved to the new class. One new method List<LintError>.doesNotContain(lintError: LintError) is added.

.editorconfig property "disabled_rules"

The .editorconfig property disabled_rules (api property DefaultEditorConfigProperties.disabledRulesProperty) has been deprecated and will be removed in a future version. Use ktlint_disabled_rules (api property DefaultEditorConfigProperties.ktlintDisabledRulesProperty) instead as it more clearly identifies that ktlint is the owner of the property. This property is to be renamed in .editorconfig files and ExperimentalParams.editorConfigOverride.

Although, Ktlint 0.47.0 falls back on property disabled_rules whenever ktlint_disabled_rules is not found, this result in a warning message being printed.

Default/alternative .editorconfig

Parameter "ExperimentalParams.editorConfigPath" is deprecated in favor of the new parameter "ExperimentalParams.editorConfigDefaults". When used in the old implementation this resulted in ignoring all ".editorconfig" files on the path to the file. The new implementation uses properties from the "editorConfigDefaults"parameter only when no ".editorconfig" files on the path to the file supplies this property for the filepath.

API consumers can easily create the EditConfigDefaults by calling "EditConfigDefaults.load(path)" or creating it programmatically.

Reload of `.editorconfig` file

Some API Consumers keep a long-running instance of the KtLint engine alive. In case an .editorconfig file is changed, which was already loaded into the internal cache of the KtLint engine this change would not be taken into account by KtLint. One way to deal with this, was to clear the entire KtLint cache after each change in an .editorconfig file.

Now, the API consumer can reload an .editorconfig. If the .editorconfig with given path is actually found in the cached, it will be replaced with the new value directly. If the file is not yet loaded in the cache, loading will be deferred until the file is actually requested again.

Example:

KtLint.reloadEditorConfigFile("/some/path/to/.editorconfig")

Miscellaneous

Several methods for which it is unlikely that they are used by API consumers have been marked for removal from the public API in KtLint 0.48.0. Please create an issue in case you have a valid business case to keep such methods in the public API.

Added

Add format reporter. This reporter prints a one-line-summary of the formatting status per file. (#621).

Fixed

Fix cli argument "--disabled_rules" (#1520).
A file which contains a single top level declaration of type function does not need to be named after the function but only needs to adhere to the PascalCase convention. filename (#1521).
Disable/enable IndentationRule on blocks in middle of file. (indent) #631
Allow usage of letters with diacritics in enum values and filenames (enum-entry-name-case, filename) (#1530).
Fix resolving of Java version when JAVA_TOOL_OPTIONS is set (#1543)
When a glob is specified then ensure that it matches files in the current directory and not only in subdirectories of the current directory (#1533).
Execute ktlint cli on default kotlin extensions only when an (existing) path to a directory is given. (#917).
Invoke callback on format function for all errors including errors that are autocorrected (#1491)
Merge first line of body expression with function signature only when it fits on the same line function-signature (#1527)
Add missing whitespace when else is on same line as true condition multiline-if-else (#1560)
Fix multiline if-statements multiline-if-else (#828)
Prevent class cast exception on ".editorconfig" property ktlint_code_style (#1559)
Handle trailing comma in enums trailing-comma (#1542)
Allow EOL comment after annotation (#1539)
Split rule trailing-comma into trailing-comma-on-call-site and trailing-comma-on-declaration-site (#1555)
Support globs containing directories in the ".editorconfig" supplied via CLI "--editorconfig" (#1551)
Fix indent of when entry with a dot qualified expression instead of simple value when trailing comma is required (#1519)
Fix whitespace between trailing comma and arrow in when entry when trailing comma is required (#1519)
Prevent false positive in parameter list for which the last value parameter is a destructuring declaration followed by a trailing comma wrapping (#1578)

Changed

Print an error message and return with non-zero exit code when no files are found that match with the globs (#629).
Invoke callback on format function for all errors including errors that are autocorrected (#1491)
Improve rule annotation (#1574)
Rename .editorconfig property disabled_rules to ktlint_disabled_rules (#701)
Allow file and directory paths in CLI-parameter "--editorconfig" (#1580)
Update Kotlin development version to 1.7.20-beta and Kotlin version to 1.7.10.
Update release scripting to set version number in mkdocs documentation (#1575).
Update Gradle to 7.5.1 version

Removed

Remove support to generate IntelliJ IDEA configuration files as this no longer fits the scope of the ktlint project (#701)

0.46.1 - 2022-06-21

Minor release to address some regressions introduced in 0.46.0

Fixed

Remove experimental flag -Xuse-k2 as it forces API Consumers to compile their projects with this same flag (#1506).
Account for separating spaces when parsing the disabled rules (#1508).
Do not remove space before a comment in a parameter list (#1509).
A delegate property which starts on the same line as the property declaration should not have an extra indentation indent (#1510)

0.46.0 - 2022-06-18

Promoting experimental rules to standard

The rules below are promoted from the experimental ruleset to the standard ruleset.

annotation
annotation-spacing
argument-list-wrapping
double-colon-spacing
enum-entry-name-case
multiline-if-else
no-empty-first-line-in-method-block
package-name
trailing-comma
spacing-around-angle-brackets
spacing-between-declarations-with-annotations
spacing-between-declarations-with-comments
unary-op-spacing

Note that as a result of moving the rules that the prefix experimental: has to be removed from all references to this rule. Check references in:

The .editorconfig setting disabled_rules.
KtLint disable and enable directives.
The VisitorModifier.RunAfterRule.

If your project did not run with the experimental ruleset enabled before, you might expect new lint violations to be reported. Please note that rules can be disabled via the the .editorconfig in case you do not want the rules to be applied on your project.

API Changes & RuleSet providers

If you are not an API user nor a RuleSet provider, then you can safely skip this section. Otherwise, please read below carefully and upgrade your usage of ktlint. In this and coming releases, we are changing and adapting important parts of our API in order to increase maintainability and flexibility for future changes. Please avoid skipping a releases as that will make it harder to migrate.

Lint and formatting functions

The lint and formatting changes no longer accept parameters of type Params but only ExperimentalParams. Also, the VisitorProvider parameter has been removed. Because of this, your integration with KtLint breaks. Based on feedback with ktlint 0.45.x, we now prefer to break at compile time instead of trying to keep the interface backwards compatible. Please raise an issue, in case you help to convert to the new API.

Use of ".editorconfig" properties & userData

The interface UsesEditorConfigProperties provides method getEditorConfigValue to retrieve a named .editorconfig property for a given ASTNode. When implementing this interface, the value editorConfigProperties needs to be overridden. Previously it was not checked whether a retrieved property was actually recorded in this list. Now, retrieval of unregistered properties results in an exception.

Property Ktlint.DISABLED has been removed. The property value can now be retrieved as follows:

astNode
    .getEditorConfigValue(DefaultEditorConfigProperties.disabledRulesProperty)
    .split(",")

and be supplied via the ExperimentalParams as follows:

ExperimentalParams(
    ...
    editorConfigOverride =  EditorConfigOverride.from(
      DefaultEditorConfigProperties.disabledRulesProperty to "some-rule-id,experimental:some-other-rule-id"
    )
    ...
)

Property Ktlint.ANDROID_USER_DATA_KEY has been removed. The property value can now be retrieved as follows:

astNode
    .getEditorConfigValue(DefaultEditorConfigProperties.codeStyleProperty)

and be supplied via the ExperimentalParams as follows:

ExperimentalParams(
    ...
    editorConfigOverride =  EditorConfigOverride.from(
      DefaultEditorConfigProperties.codeStyleProperty to "android" 
    )
    ...
)

This property defaults to the official Kotlin code style when not set.

Testing KtLint rules

An AssertJ style API for testing KtLint rules (#1444) has been added. Usage of this API is encouraged in favor of using the old RuleExtension API. For more information, see KtLintAssertThat API

Added

Add experimental rule for unexpected spacing between function name and opening parenthesis (spacing-between-function-name-and-opening-parenthesis) (#1341)
Add experimental rule for unexpected spacing in the parameter list (parameter-list-spacing) (#1341)
Add experimental rule for incorrect spacing around the function return type (function-return-type-spacing) (#1341)
Add experimental rule for unexpected spaces in a nullable type (nullable-type-spacing) (#1341)
Do not add a space after the typealias name (type-parameter-list-spacing) (#1435)
Add experimental rule for consistent spacing before the start of the function body (function-start-of-body-spacing) (#1341)
Suppress ktlint rules using @Suppress (more information) (#765)
Add experimental rule for rewriting the function signature (function-signature) (#1341)

Fixed

Move disallowing blank lines in chained method calls from no-consecutive-blank-lines to new rule (no-blank-lines-in-chained-method-calls) (#1248)
Fix check of spacing in the receiver type of an anonymous function (#1440)
Allow comment on same line as super class in class declaration wrapping (#1457)
Respect git hooksPath setting (#1465)
Fix formatting of a property delegate with a dot-qualified-expression indent (#1340)
Keep formatting of for-loop in sync with default IntelliJ formatter (indent) and a newline in the expression in a for-statement should not force to wrap it wrapping (#1350)
Fix indentation of property getter/setter when the property has an initializer on a separate line indent (#1335)
When .editorconfig setting indentSize is set to value tab then return the default tab width as value for indentSize (#1485)
Allow suppressing all rules or a list of specific rules in the entire file with @file:Suppress(...) (#1029)

Changed

Update Kotlin development version to 1.7.0 and Kotlin version to 1.7.0.
Update shadow plugin to 7.1.2 release
Update picocli to 4.6.3 release
A file containing only one (non private) top level declaration (class, interface, object, type alias or function) must be named after that declaration. The name also must comply with the Pascal Case convention. The same applies to a file containing one single top level class declaration and one ore more extension functions for that class. filename (#1004)
Promote experimental rules to standard rules set: annotation, annotation-spacing, argument-list-wrapping, double-colon-spacing, enum-entry-name-case, multiline-if-else, no-empty-first-line-in-method-block, package-name, traling-comma, spacing-around-angle-brackets, spacing-between-declarations-with-annotations, spacing-between-declarations-with-comments, unary-op-spacing (#1481)
The CLI parameter --android can be omitted when the .editorconfig property ktlint_code_style = android is defined

0.45.2 - 2022-04-06

Fixed

Resolve compatibility issues introduced in 0.45.0 and 0.45.1 (#1434). Thanks to mateuszkwiecinski and jeremymailen for your input on this issue.

Changed

Set Kotlin development version to 1.6.20 and Kotlin version to 1.6.20.

0.45.1 - 2022-03-21

Minor release to fix a breaking issue with ktlint API consumers

Fixed

Remove logback dependency from ktlint-core module (#1421)

0.45.0 - 2022-03-18

API Changes & RuleSet providers

If you are not an API user nor a RuleSet provider, then you can safely skip this section. Otherwise, please read below carefully and upgrade your usage of ktlint. In this and coming releases, we are changing and adapting important parts of our API in order to increase maintainability and flexibility for future changes. Please avoid skipping a releases as that will make it harder to migrate.

Retrieving ".editorconfig" property value

This section is applicable when providing rules that depend on one or more values of ".editorconfig" properties. Property values should no longer be retrieved via EditConfig or directly via userData[EDITOR_CONFIG_USER_DATA_KEY]. Property values should now only be retrieved using method ASTNode.getEditorConfigValue(editorConfigProperty) of interface UsesEditorConfigProperties which is provided in this release. Starting from next release after the current release, the EditConfig and/or userData[EDITOR_CONFIG_USER_DATA_KEY] may be removed without further notice which will break your API or rule. To prevent disruption of your end user, you should migrate a.s.a.p.

Added

Add experimental rule for unexpected spaces in a type reference before a function identifier (function-type-reference-spacing) (#1341)
Add experimental rule for incorrect spacing after a type parameter list (type-parameter-list-spacing) (#1366)
Add experimental rule to detect discouraged comment locations (discouraged-comment-location) (#1365)
Add rule to check spacing after fun keyword (fun-keyword-spacing) (#1362)
Add experimental rules for unnecessary spacing between modifiers in and after the last modifier in a modifier list (#1361)
New experimental rule for aligning the initial stars in a block comment when present (experimental:block-comment-initial-star-alignment (#297)
Respect .editorconfig property ij_kotlin_packages_to_use_import_on_demand (no-wildcard-imports) (#1272)
Add new experimental rules for wrapping of block comment (comment-wrapping) (#1403)
Add new experimental rules for wrapping of KDoc comment (kdoc-wrapping) (#1403)
Add experimental rule for incorrect spacing after a type parameter list (type-parameter-list-spacing) (#1366)
Expand check task to run tests on JDK 17 - "testOnJdk17"

Fixed

Fix lint message to "Unnecessary long whitespace" (no-multi-spaces) (#1394)
Do not remove trailing comma after a parameter of type array in an annotation (experimental:trailing-comma) (#1379)
Do not delete blank lines in KDoc (no-trailing-spaces) (#1376)
Do not indent raw string literals that are not followed by either trimIndent() or trimMargin() (indent) (#1375)
Revert remove unnecessary wildcard imports as introduced in Ktlint 0.43.0 (no-unused-imports) (#1277), (#1393), (#1256)
(Possibly) resolve memory leak (#1216)
Initialize loglevel in Main class after parsing the CLI parameters (#1412)

Changed

Print the rule id always in the PlainReporter (#1121)
All wrapping logic is moved from the indent rule to the new rule wrapping (as part of the standard ruleset). In case you currently have disabled the indent rule, you may want to reconsider whether this is still necessary or that you also want to disable the new wrapping rule to keep the status quo. Both rules can be run independent of each other. (#835)

0.44.0 - 2022-02-15

Please welcome paul-dingemans as an official maintainer of ktlint!

Added

Use Gradle JVM toolchain with language version 8 to compile the project
Basic tests for CLI (#540)
Add experimental rule for unnecessary parentheses in function call followed by lambda (#1068)

Fixed

Fix indentation of function literal (#1247)
Fix false positive in rule spacing-between-declarations-with-annotations (#1281)
Do not remove imports for same class when different alias is used (#1243)
Fix NoSuchElementException for property accessor (trailing-comma) (#1280)
Fix ClassCastException using ktlintFormat on class with KDoc (no-trailing-spaces) (#1270)
Do not remove trailing comma in annotation (#1297)
Do not remove import which is used as markdown link in KDoc only (no-unused-imports) (#1282)
Fix indentation of secondary constructor (indent) (#1222)
Custom gradle tasks with custom ruleset results in warning (#1269)
Fix alignment of arrow when trailing comma is missing in when entry (trailing-comma) (#1312)
Fix indent of delegated super type entry (indent) (#1210)
Improve indentation of closing quotes of a multiline raw string literal (indent) (#1262)
Trailing space should not lead to delete of indent of next line (no-trailing-spaces) (#1334)
Force a single line function type inside a nullable type to a separate line when the max line length is exceeded (parameter-list-wrapping) (#1255)
A single line function with a parameter having a lambda as default argument does not throw error (indent) (#1330)
Fix executable jar on Java 16+ (#1195)
Fix false positive unused import after autocorrecting a trailing comma (#1367)
Fix false positive indentation (parameter-list-wrapping, argument-list-wrapping) (#897, #1045, #1119, #1255, #1267, #1319, #1320, #1337
Force a single line function type inside a nullable type to a separate line when the max line length is exceeded (parameter-list-wrapping) (#1255)

Changed

Update Kotlin version to 1.6.0 release
Add separate tasks to run tests on JDK 11 - "testOnJdk11"
Update Dokka to 1.6.0 release
Apply ktlint experimental rules on the ktlint code base itself.
Update shadow plugin to 7.1.1 release
Add Kotlin-logging backed by logback as logging framework (#589)
Update Gradle to 7.4 version

0.43.2 - 2021-12-01

Fixed

KtLint CLI 0.43 doesn't work with JDK 1.8 (#1271)

0.43.0 - 2021-11-02

Added

New trailing-comma rule (#709) (prior art by paul-dingemans)

Fixed

Fix false positive with lambda argument and call chain (indent) (#1202)
Fix trailing spaces not formatted inside block comments (no-trailing-spaces) (#1197)
Do not check for .idea folder presence when using applyToIDEA globally (#1186)
Remove spaces before primary constructor (paren-spacing) (#1207)
Fix false positive for delegated properties with a lambda argument (indent) (#1210)
(REVERTED in Ktlint 0.45.0) Remove unnecessary wildcard imports (no-unused-imports) (#1256)
Fix indentation of KDoc comment when using tab indentation style (indent) (#850)

Changed

Support absolute paths for globs (#1131)
Fix regression from 0.41 with argument list wrapping after dot qualified expression (argument-list-wrapping)(#1159)
Update Gradle to 7.2 version
Update Gradle shadow plugin to 7.1 version
Update Kotlin version to 1.5.31 version. Default Kotlin API version was changed to 1.4!

0.42.1 - 2021-08-06

Dot release to fix regressions in indent rule introduced in 0.42.0 release. Thanks to t-kameyama for the fixes!

Fixed

Fix false positive with delegated properties (indent) (#1189)
Fix false positive with lambda argument in super type entry (indent) (#1188)

0.42.0 - 2021-07-29

Thank you to the following contributors for this release:

abbenyyyyyy
carloscsanz
chao2zhang
ganadist
insiderser
paul-dingemans
rciovati
t-kameyama

Added

SARIF output support (#1102)

Fixed

Remove needless blank lines in dot qualified expression (#1077)
Fix false positives for SpacingBetweenDeclarationsWithAnnotationsRule (#1125)
Fix false positive with eol comment (annotation-spacing) (#1124)
Fix KtLint dependency variant selection (#1114)
Fix false positive with 'by lazy {}' (indent) (#1162)
Fix false positive with value argument list has lambda (indent) (#764)
Fix false positive in lambda in dot qualified expression (argument-list-wrapping) (#1112)
Fix false positive with multiline expression with elvis operator in assignment (indent) (#1165)
Ignore backticks in imports for ordering purposes (import-ordering) (#1106)
Fix false positive with elvis operator and comment (chain-wrapping) (#1055)
Fix false negative in when conditions (chain-wrapping) (#1130)
Fix the Html reporter Chinese garbled (#1140)
Performance regression introduced in 0.41.0 (#1135)

Changed

Updated to dokka 1.4.32 (#1148)
Updated Kotlin to 1.5.20 version

0.41.0 - 2021-03-16

Note: This release contains breaking changes to globs passed to ktlint via the command line. See (#999) and the README.

Thank you to t-kameyama and paul-dingemans for your contributions to this release!

Added

New ktlint_ignore_back_ticked_identifier EditorConfig option for max-line-length rule to ignore long method names inside backticks (primarily used in tests) (#1007)
Allow to add/replace loaded .editorconfig values via ExperimentalParams#editorConfigOverride (#1016)
ReporterProvider, LintError, RuleSetProvider now implement Serializable interface

Fixed

Incorrect indentation with multiple interfaces (#1003)
Empty line before primary constructor is not reported and formatted-out (#1004)
Fix '.editorconfig' generation for "import-ordering" rule (#1011)
Fix "filename" rule will not work when '.editorconfig' file is not found (#997)
EditorConfig generation for import-ordering (#1011)
Internal error (no-unused-imports) (#996)
Fix false positive when argument list is after multiline dot-qualified expression (argument-list-wrapping) (#893)
Fix indentation for function types after a newline (indent) (#918)
Don't remove the equals sign for a default argument (no-line-break-before-assignment) (#1039)
Fix internal error in no-unused-imports (#1040)
Fix false positives when declaration has tail comments (spacing-between-declarations-with-comments) (#1053)
Fix false positive after else keyword (argument-list-wrapping) (#1047)
Fix formatting with comments (colon-spacing) (#1057)
Fix IndexOutOfBoundsException in argument-list-wrapping-rule formatting file with many corrections (#1081)
Fix formatting in arguments (multiline-if-else) (#1079)
Fix experimental:annotation-spacing-rule autocorrection with comments
Migrate from klob dependency and fix negated globs passed to CLI are no longer worked (#999) Breaking: absolute paths globs will no longer work, check updated README

Changed

Update Gradle shadow plugin to 6.1.0 version
Align with Kotlin plugin on how alias pattern is represented for imports layout rule (#753)
Align with Kotlin plugin on how subpackages are represented (#753)
Deprecated custom kotlin_imports_layout EditorConfig property. Please use ij_kotlin_imports_layout to ensure that the Kotlin IDE plugin and ktlint use same imports layout (#753)
Deprecated idea and ascii shortcuts as the ij_kotlin_imports_layout property does not support those. Please check README on how to achieve those with patterns (#753)
Update Gradle to 6.8.3 version
Update Kotlin to 1.4.31 version. Fixes #1063.

0.40.0 - 2020-12-04

Special thanks to t-kameyama for the huge number of bugfixes in this release!

Added

Initial implementation IDE integration via '.editorconfig' based on rules default values (#701)
CLI subcommand generateEditorConfig to generate '.editorconfig' content for Kotlin files (#701)
A new capability to generate baseline and run ktlint against it with --baseline cli option (#707)

Fixed

Do not report when semicolon is before annotation/comment/kdoc and lambda (#825)
Fix false positive when import directive has backticks and alias (#910)
@receiver annotations with parameters are not required to be on a separate line (#885)
Fix false positive "File annotations should be separated from file contents with a blank line" in kts files (#914)
Fix false positive Missing newline after "->" when when entry has a nested if/else block (#901)
Allow an inline block comment in argument-list-wrapping (#926)
Fix false positive for line-breaks inside lambdas in argument-list-wrapping (#861) (#870)
Fix wrong indentation inside an if-condition in argument-list-wrapping (#854) (#864)
Fix false positive for method after string template in argument-list-wrapping (#842) (#859)
Fix false positive when a comment is not between declarations in spacing-between-declarations-with-comments(#865)
Fix formatting with comments (multiline-if-else) (#944)
Do not insert unnecessary spacings inside multiline if-else condition (indent) (#871) (#900)
Correctly indent primary constructor parameters when class has multiline type parameter (parameter-list-wrapping) (#921) (#938)
Correctly indent property delegates (indent) (#939)
Fix false positive for semicolon between empty enum entry and member (no-semicolons) (#957)
Fix wrong indentation for class delegates (indent) (#960) (#963) (#877)
Fix wrong indentation in named arguments (indent) (#964)
Fix wrong indentation when a function has multiline type arguments (parameter-list-wrapping) (#965)
Fix false positive for spacing-between-declarations-with-annotations (#970)
Fix ParseException when an assigment contains comments (no-line-break-before-assignment) (#956)
Fix false positive when right brace is after a try-catch block (spacing-around-keyword) (#978)
Fix false positive for control flow with empty body (no-semicolons) (#955)
Fix incorrect indentation for multi-line call expressions in conditions (indent) (#959)
Fix false positive for trailing comma before right parentheses|bracket|angle (spacing-around-comma) (#975)
Fix ktlint CLI could skip checking some of explicetly passed files (#942)

Changed

'import-ordering' now supports `.editorconfig' default value generation (#701)
Update Gradle to 6.7.1 version

0.39.0 - 2020-09-14

Added

Add new applyToIDEA location for IDEA 2020.1.x and above on MacOs
Debug output: print loaded .editorconfig content
Extract argument-list-wrapping rule into experimental ruleset
Split annotation-spacing into separate experimental rule

Fixed

Do not enforce raw strings opening quote to be on a separate line (#711)
False negative with multiline type parameter list in function signature for parameter-list-wrapping(#680)
Alternative .editorconfig path is ignored on stdin input (#869)
False positive with semicolons before annotations/comments/kdoc (#825)
Do not report when string-template expression is a keyword (#883)
False positive for subclass imports in no-unused-imports (#845)
False positive for static java function imports in no-unused-imports (#872)
Missing signature for KtLint CLI artifact published to Github release (#895)
Crash in annotation rule (#868)
False-positive unused import violation (#902)

Changed

Ktlint object internal code cleanup
Deprecate some of public methods in Ktlint object that should not be exposed as public api
Update Kotlin to 1.4.10 version
Make RuleSet class open so it can be inherited

0.38.1 - 2020-08-24

Minor release to support projects using mixed 1.3/1.4 Kotlin versions (e.g. Gradle plugins)

Changed

Compile with apiLevel = 1.3

0.38.0 - 2020-08-21

New release with Kotlin 1.4.0 support and several enhancements and bugfixes.

Added

Experimental SpacingAroundAngleBracketsRule (#769)
Checksum generation for executable Jar (#695)
Enable Gradle dependency verification
parameter-list-wrapping rule now also considers function arguments while wrapping (#620)
Publish snapshots built against kotlin development versions
Initial support for tab-based indentation (#128)

Fixed

Safe-called wrapped trailing lambdas indented correctly (#776)
provideDelegate imports are not marked as unused anymore (#669)
Set continuation indent to 4 in IDE integration codestyle (#775)
No empty lines between annotation and annotated target (#688)
Unused imports reported correctly (#526) (#405)
No false empty lines inserted in multiline if-else block (#793)
No-wildcard-imports properly handles custom infix function with asterisk (#799)
Do not require else to be in the same line of a right brace if the right brace is not part of the if statement (#756)
Brace-less if-else bodies starting with parens indented correctly (#829)
If-condition with multiline call expression inside indented correctly (#796)

Changed

Update Gradle to 6.6 version
Update ec4j to 0.2.2 version. Now it should report path to .editorconfig file on failed parsing and allow empty .editorconfig files.
Update Kotlin to 1.4.0 version (#830)

0.37.2 - 2020-06-16

Minor release to fix further bugs in ImportOrderingRule.

Fixed

Imports with aliases no longer removed (#766)

0.37.1 - 2020-06-08

Minor release to fix some bugs in the 0.37.0 release.

Fixed

Invalid path exception error on Windows machines when loading properties from .editorconfig (#761)
Imports with as no longer removed (#766)
The contents of raw strings are no longer modified by the indent rule (#682)

0.37.0 - 2020-06-02

Thank you to Tapchicoma and romtsn for all their hard work on this release!

Added

Gradle wrapper validation (#684)
Experimental SpacingAroundDoubleColon rule (#722]
Experimental SpacingBetweenDeclarationsWithCommentsRule and SpacingBetweenDeclarationsWithAnnotationsRule. Fixes ([#721]pinterest#721)
kotlin_imports_layout config for .editorconfig file so that import ordering is configurable. Fixes (#527)

Changed

Kotlin was updated to 1.3.70 version
Loading properties from .editorconfig was fully delegated to ec4j library. This fixes ability to override properties for specific files/directories (#742)
Promote experimental "indent" rule to standard one, old standard "indent" rule is removed
Functions to calculate line/column are now public so they can be used by 3rd party tools (#725)
AnnotationRule now handles file annotations as well (#714)

Fixed

Ignore keywords in KDoc comments (#671)
Allow multiple spaces in KDoc comments (#706)
Trailing comment no longer reported as incorrect indentation (#710]
Annotated function types no longer reported as an error (#737)
FinalNewlineRule no longer reports error for empty files (#723)
EOL comments will no longer cause AnnotationRule to report an error (#736)
Formatter will no longer break class declaration with trailing comment (#728)
Formatting for single line if/else statements (#174)
Exception in NoLineBreakBeforeAssignmentRule (#693)

Removed

Removed Maven; builds all run under Gradle (#445)
Old standard IndentRule

0.36.0 - 2019-12-03

Added

HTML reporter (#641)
Experimental rule to lint enum entry names (#638)
@Suppress("RemoveCurlyBracesFromTemplate") now respected (#263)

Upgraded

Gradle version to 5.6.2 (#616)
Kotlin to 1.3.60 (#658)

Fixed

.git directory now discovered instead of hardcoded (#623)
Several bugs with the experimental annotation rule (#628) (#642) (#654) (#624)
Allow newline after lambda return type (#643)
Allow empty first line in a function that returns an anonymous object (#655)
Indentation with lambda argument (#627)
ktlint can now lint UTF-8 files with BOM (#630
Indentation with newline before return type (#663)
Build/tests on Windows (#640)
Allow whitespace after ( followed by a comment (#664)

0.35.0 - 2019-10-12

Added

Support for specifying color for output via --color-name command line flag. (#585)
Support for custom rulesets and providers on Java 9+ (#573)

Deprecated

--apply-to-idea flag; use applyToIDEA subcommand instead (#554)
--apply-to-idea-project flag; use applyToIDEAProject subcommand instead (#593)
0.0.0-SNAPSHOT builds; snapshot builds are now versioned, e.g. 0.35.0-SNAPSHOT (#588)
- Note: When using the new snapshot builds, you may need to add an explicit dependency on kotlin-compiler-embeddable to your ruleset project.

Removed

Support for loading 3rd party rulesets via Maven (#566)

Upgraded

Kotlin version to 1.3.50 (#565) (#611)

Fixed

Bugs with spacing in experimental AnnotationRule (#552) (#601
Brackets would be removed from empty companion object (#600)
Bugs with experimental IndentationRule (#597) (#599)
Erroneous space between } and ] (#596)
Spacing around multiplication sign in lambdas (#598)
--version output with gradle-built JAR (#613)

0.34.2 - 2019-07-22

Minor bugfix release for 0.34.0. (Note: 0.34.1 deprecated/deleted due to regression in disabled_flags .editorconfig support.)

Added

Support for globally disabling rules via --disabled_rules command line flag. (#534)

Fixed

Regression with --stdin flag for printAST command (#528)
Regressions with NoUnusedImports rule (#531, #526)
- Note: this re-introduces #405
Indentation for enums with multi-line initializers (#518)

0.34.0 - 2019-07-15

Added

Support for Kotlin 1.3.41
Support for globally disabling rules via custom disabled_rules property in .editorconfig (#503)
experimental:no-empty-first-line-in-method-block (#474)
Unit tests for ruleset providers

Upgraded

AssertJ from 3.9.0 to 3.12.2 (#520)

Enabled

Final newline by default (#446)
no-wildcard-import (Re-enabled after temporarily disabling in 0.33.0)
experimental:annotation (#509)
experimental:multiline-if-else (no autocorrection)
experimental:package-name (currently only disallows underscores in package names)

Deprecated

MavenDependencyResolver. Scheduled to be removed in 0.35.0 (#468)
--install-git-pre-commit-hook flag; use installGitPreCommitHook subcommand instead (#487)
--print-ast flag; use printAST subcommand instead (#500)

Removed

Support for --ruleset-repository and --ruleset-update flags

Fixed

import-ordering will now refuse to format import lists that contain top-level comments (#408)
no-unused-imports reporting false negatives or false positives in some cases (#405) and (#506)
experimental:indent incorrectly formatting a lambda's closing brace (#479)

0.33.0 - 2019-05-28

Added

Support for Kotlin 1.3.31

Disabled

No wildcard imports rule (#48). Developers wishing to still enforce this rule should add the code into a custom ruleset.

Fixed

Spec file parsing is now platform-agnostic (#365)
Unnecessary newline after -> in some cases (#403)
SpacingAroundCommaRule will no longer move code into comments
Made newlines after = less aggressive (#368) (#380)
Erroneous newline when parameter comments are used (#433)

0.32.0 - 2019-04-22

Added

experimental/import-ordering rule (#189). Use ktlint --experimental to enabled.
Support for Kotlin 1.3.30
Build now compatible with jitpack
ktlint now part of Homebrew core (shyiko/ktlint tap deprecated)

Fixed

Incorrectly flagging a missing newline for functions with no parameters (#327).
Semicolons now allowed in KDocs (#362).
Spaces now disallowed after super (#369).
Annotations in function parameters now checked for indentation (#374]

Changed

Code now lives in com.pinterest package
groupId now com.pinterest
Custom ruleset META-INF.services file must be renamed to com.pinterest.ktlint.core.RuleSetProvider

0.31.0 - 2019-03-10

Added

dot-spacing rule (#293).
experimental/indent rule (#338).
Use ktlint --experimental to enable.

Fixed

Spacing check around < & > operators.

Changed

no-multi-spaces rule (horizontal alignment of comments is no longer allowed) (#269).
colon-spacing rule (: must not appear at the beginning of the line).
package-name rule (disabled until #208 is resolved).
--print-ast to output com.pinterest.ktlint.core.ast.ElementType.* as node.elementType, e.g.

$ echo 'fun f() {}' | ./ktlint/target/ktlint --print-ast --color --stdin
1: ~.psi.KtFile (FILE)
1:   ~.psi.KtPackageDirective (PACKAGE_DIRECTIVE) ""
1:   ~.psi.KtImportList (IMPORT_LIST) ""
1:   ~.psi.KtScript (SCRIPT)
1:     ~.psi.KtBlockExpression (BLOCK)
1:       ~.psi.KtNamedFunction (FUN)
1:         ~.c.i.p.impl.source.tree.LeafPsiElement (FUN_KEYWORD) "fun"
1:         ~.c.i.p.impl.source.tree.PsiWhiteSpaceImpl (WHITE_SPACE) " "
1:         ~.c.i.p.impl.source.tree.LeafPsiElement (IDENTIFIER) "f"
1:         ~.psi.KtParameterList (VALUE_PARAMETER_LIST)
1:           ~.c.i.p.impl.source.tree.LeafPsiElement (LPAR) "("
1:           ~.c.i.p.impl.source.tree.LeafPsiElement (RPAR) ")"
1:         ~.c.i.p.impl.source.tree.PsiWhiteSpaceImpl (WHITE_SPACE) " "
1:         ~.psi.KtBlockExpression (BLOCK)
1:           ~.c.i.p.impl.source.tree.LeafPsiElement (LBRACE) "{"
1:           ~.c.i.p.impl.source.tree.LeafPsiElement (RBRACE) "}"
1:       ~.c.i.p.impl.source.tree.PsiWhiteSpaceImpl (WHITE_SPACE) "\n"

   format: <line_number:> <node.psi::class> (<node.elementType>) "<node.text>"
   legend: ~ = org.jetbrains.kotlin, c.i.p = com.intellij.psi

kotlin-compiler version to 1.3.21 (from 1.3.20).

Removed

Dependency on JCenter (#349).

0.30.0 - 2019-02-03

Fixed

Missing newline before ")" (#327).

Changed

kotlin-compiler version to 1.3.20 (from 1.2.71) (#331).

Security

--ruleset/--reporter switched to HTTPS (#332).

0.29.0 - 2018-10-02

Fixed

no-semi rule to preserve semicolon after companion object; (see #281 for details).
"line number off by one" when end_of_line=CRLF is used (#286).

Changed

package-name rule not to check file location (until #280 can be properly addressed).
comment-spacing rule not to flag //region & //endregion comments (#278).
kotlin-compiler version to 1.2.71 (from 1.2.51).

0.28.0 - 2018-09-05

Fixed

ktlint hanging in case of unhandled exception in a reporter (#277).

Changed

package-name rule (directories containing . in their names are no longer considered to be invalid) (#276).

0.27.0 - 2018-08-06

Changed

ktlint output (report location is now printed only if there are style violations) (#267).

0.26.0 - 2018-07-30

Changed

max-line-length rule (multi-line strings are no longer checked) (#262).

0.25.1 - 2018-07-25

Fixed

json reporter \ and control characters escaping (#256).

0.25.0 - 2018-07-25

Added

package-name rule (#246).
--editorconfig=path/to/.editorconfig (#250).
Support for end_of_line=native (.editorconfig) (#225).
tab -> space * indent_size auto-correction (--format/-F).

Fixed

"Unnecessary semicolon" false positive (#255).
(cannot be auto-corrected) reporting.
OOM in --debug mode while trying to print root=true <- root=false .editorconfig chain.

Changed

kotlin-compiler version to 1.2.51 (from 1.2.50).

0.24.0 - 2018-06-22

Added

paren-spacing rule (#223).
Report location output (#218, #224).
An indication that some lint errors cannot be auto-corrected (#219).
Git hook to automatically check files for style violations on push (an alternative to existing ktlint --install-git-pre-commit-hook)
(execute ktlint --install-git-pre-push-hook to install) (#229).
Support for end_of_line=crlf (.editorconfig) (#225).

Fixed

.editorconfig path resolution
(you no longer need to be inside project directory for .editorconfig to be loaded) (#207).
NPE in case of I/O error (klob@0.2.1).

Changed

comment-spacing rule to exclude //noinspection (#212).
kotlin-compiler version to 1.2.50 (from 1.2.41) (#226).

0.23.1 - 2018-05-04

Fixed

ClassCastException: cannot be cast to LeafPsiElement (#205).

0.23.0 - 2018-05-02

Added

comment-spacing (#198),
filename (#194) rules.
parameter-list-wrapping left parenthesis placement check (#201).
parameter-list-wrapping auto-correction when max_line_length is exceeded (#200).

Fixed

"Unused import" false positive (x.y.zNNN import inside x.y.z package) (#204).

Changed

kotlin-compiler version to 1.2.41 (from 1.2.40).

0.22.0 - 2018-04-22

Added

--apply-to-idea-project (as an alternative to (global) --apply-to-idea) (#178).
Check to verify that annotations are placed before the modifiers (#183).
Access to PsiFile location information (#194).

Fixed

--format commenting out operators (chain-wrapping rule) (#193).

Changed

indent rule (continuation_indent_size is now ignored) (#171).
NOTE: if you have a custom continuation_indent_size (and gcd(indent_size, continuation_indent_size) == 1) ktlint won't check the indentation.
--apply-to-idea to inherit "Predefined style / Kotlin style guide" (Kotlin plugin 1.2.20+).
kotlin-compiler version to 1.2.40 (from 1.2.30).

0.21.0 - 2018-03-29

Changed

indent rule to ignore where <type constraint list> clause (#180).

0.20.0 - 2018-03-20

Added

Ability to load 3rd party reporters from the command-line (e.g. --reporter=<name>,artifact=<group_id>:<artifact_id>:<version>) (#176).
--ruleset/--reporter dependency tree validation.

Fixed

Handling of spaces in --reporter=...,output=<path_to_a_file> (#177).
+, -, *, /, %, &&, || wrapping (#168).

Changed

comma-spacing rule to be more strict (#173).
no-line-break-after-else rule to allow multi-line if/else without curly braces.

0.19.0 - 2018-03-04

Changed

Lambda formatting: if lambda is assigned a label, there should be no space between the label and the opening curly brace (#167).

0.18.0 - 2018-03-01

Added

Java 9 support (#152).

Changed

kotlin-compiler version to 1.2.30 (from 1.2.20).

0.17.1 - 2018-02-28

Fixed

Internal Error (parameter-list-wrapping) when indent_size=unset (#165).

0.17.0 - 2018-02-28

Fixed

+/- wrapping inside catch block, after else and if (..) (#160).
Multi-line parameter declaration indentation (#161).
Expected indentation reported by indent rule.

Changed

Error code returned by ktlint --format/-F when some of the errors cannot be auto-corrected (previously it was 0 instead of expected 1) (#162).

0.16.1 - 2018-02-27

Fixed

Handling of negative number condition in when block (#160).

0.16.0 - 2018-02-27

Added

parameter-list-wrapping rule (#130).
+, -, *, /, %, &&, || wrapping check (now part of chain-wrapping rule).

Fixed

Unused componentN import (where N > 5) false positive (#142).
max-line-length error suppression (#158).

Changed

modifier-order rule to match official Kotlin Coding Conventions (#146)
(override modifier should be placed before suspend/tailrec, not after)

0.15.1 - 2018-02-14

Fixed

Race condition when multiple rules try to modify AST node that gets detached as a result of mutation (#154).

0.15.0 - 2018-01-18

Added

no-line-break-after-else rule (#125).

Changed

kotlin-compiler version to 1.2.20 (from 1.2.0).

0.14.0 - 2017-11-30

Changed

continuation_indent_size to 4 when --android profile is used (android/kotlin-guides#37).

Fixed

Maven integration (#117).

0.13.0 - 2017-11-28

Added

no-line-break-before-assignment (#105),
chain-wrapping (#23) (when wrapping chained calls ., ?. and ?: should be placed on the next line),
range-spacing (no spaces around range (..) operator) rules.
--print-ast CLI option which can be used to dump AST of the file
(see README / Creating a ruleset / AST for more details)
--color CLI option for colored output (where supported, e.g. --print-ast, default (plain) reporter, etc)

Changed

.editorconfig property resolution.
An explicit [*.{kt,kts}] is not required anymore (ktlint looks for sections containing *.kt (or *.kts) and will fallback to [*] whenever property cannot be found elsewhere).
Also, a search for .editorconfig will no longer stop on first (closest) .editorconfig (unless it contains root=true).
max-line-length rule to assume max_line_length=100 when ktlint --android ... is used
(per Android Kotlin Style Guide).
kotlin-compiler version to 1.2.0 (from 1.1.51).

Fixed

no-empty-class-body auto-correction at the end of file (#109).
max-line-length rule when applied to KDoc (#112)
(previously KDoc was subject to max-line-length even though regular comments were not).
Spacing around = in @annotation|s (op-spacing).
Spacing around generic type parameters of functions (e.g. fun <T>f(): T {} -> fun <T> f(): T {}).
no-consecutive-blank-lines not triggering at the end of file (when exactly 2 blank lines are present) (#108)
indent continuation_indent_size % indent_size != 0 case (#76)
indent rule skipping first parameter indentation check.
final-newline rule in the context of kotlin script.
Git hook (previously files containing space character (among others) in their names were ignored)
Exit code when file cannot be linted due to the invalid syntax or internal error.

0.12.1 - 2017-11-13

Fixed

A conflict between org.eclipse.aether:aether-*:1.1.0 and org.eclipse.aether:aether-*:1.0.0.v20140518 (#100).

0.12.0 - 2017-11-10

Added

--android (-a) CLI option (turns on Android Kotlin Style Guide compatibility)
(right now it's used only by ktlint --apply-to-idea).

Changed

ktlint --apply-to-idea to account for indent_size & continuation_indent_size in .editorconfig (if any).

Removed

ktlint-intellij-idea-integration binary (deprecated in 0.9.0).

Fixed

"Unused import" false positive (component1..component5).

0.11.1 - 2017-10-26

Fixed

--reporter's output handling (previously parent directory was expected to exist) (#97).

0.11.0 - 2017-10-25

Added

no-blank-line-before-rbrace rule (#65).

Fixed

Redundant space inserted between } and :: (curly-spacing).

0.10.2 - 2017-10-25 [YANKED]

This release contains changes that were meant for 0.11.0 and so it was retagged as such.

0.10.1 - 2017-10-22

Fixed

Redundant space inserted between } and [key]/(...) (curly-spacing) (#91).

0.10.0 - 2017-10-10

Added

Git hook to automatically check files for style violations on commit
(execute ktlint --install-git-pre-commit-hook to install).
Ability to specify multiple reporters
(output can be controlled with --reporter=<name>,output=<path/to/file>) (#71).
Support for indent_size=unset (.editorconfig) (#70).

Fixed

( { formatting
(previously both ( { and ({ were accepted as correct, while only ({ should be) (curly-spacing rule) (#80).
if\nfn {}\nelse formatting (curly-spacing rule).
max_line_length=off & max_line_length=unset handling (.editorconfig).

Changed

kotlin-compiler version to 1.1.51 (from 1.1.3-2).
ktlint --apply-to-idea to include OPTIMIZE_IMPORTS_ON_THE_FLY=true.

0.9.2 - 2017-09-01

Fixed

: Unit = formatting (: Unit is no longer dropped when = is used) (#77).

0.9.1 - 2017-07-30

Fixed

${super.toString()} linting (string-template rule) (#69).

0.9.0 - 2017-07-23

Added

Reporter API.
ktlint comes with 3 built-in reporters: plain (default; ?group_by_file can be appended to enable grouping by file (shown below)), json and checkstyle.

$ ktlint --reporter=plain?group_by_file
path/to/file.kt
  1:10 Unused import.
  2:10 Unnecessary "Unit" return type.
path/to/another-file.kt
  1:10 Unnecessary semicolon.

string-template,
no-empty-class-body,
max-line-length (#47),
final-newline (activated only if insert_final_newline is set in .editorconfig (under [*.{kt,kts}])) rules.
--limit CLI option (e.g. use --limit=10 to limit the number of errors to display).
--relative CLI flag which makes ktlint output file paths relative to working directory (e.g. dir/file.kt instead of /home/269/project/dir/file.kt).

Changed

BREAKING: JDK version to 1.8 (as a result of upgrading kotlin-compiler to 1.1.3-2 (from 1.1.0)).
File matching (offloaded to klob).

Deprecated

--ruleset-repository and --ruleset-update CLI arguments in favour of --repository and --repository-update respectively (--ruleset-* will be removed in 1.0.0).
ktlint-intellij-idea-integration binary
(Intellij IDEA integration task is now included in ktlint (as ktlint --apply-to-idea)).

0.8.3 - 2017-06-19

Fixed

"Missing spacing after ";"" at the end of package declaration (#59).
"Unused import" false positive (setValue) (#55).
get/setter spacing (#56).

0.8.2 - 2017-06-06

Fixed

"Unused import" false positive (getValue) (#54).

0.8.1 - 2017-05-30

Fixed

ktlint --stdin (#51).

0.8.0 - 2017-05-30

Added

.editorconfig support (right now only indent_size is honored and only if it's set in [*{kt,kts}] section).
Support for vertically aligned comments (see NoMultipleSpacesRuleTest.kt).

Fixed

ktlint-ruleset-standard ("no-unit-return" & "modifier-order" where not included).

0.7.1 - 2017-05-29

Fixed

Triggering of "Unused import" when element is referenced in KDoc(s) only (#46).

0.7.0 - 2017-05-28

Added

no-unit-return rule.
modifier-order rule (#42).
else/catch/finally on the same line as } check (now part of "keyword-spacing" rule).
ktlint-intellij-idea-integration binary for easy Intellij IDEA config injection.

0.6.2 - 2017-05-22

Fixed

Unused "iterator" extension function import false positive (#40).

0.6.1 - 2017-03-06

Fixed

Detection of unnecessary "same package" imports (no-unused-imports).
FileNotFoundException while scanning FS (#36).

0.6.0 - 2017-03-01

Changed

kotlin-compiler version to 1.1.0 (from 1.1-M04).

0.5.1 - 2017-02-28

Fixed

Unnecessary spacing around angle brackets in case of super<T> (#34).

0.5.0 - 2017-02-20

Fixed

Redundant space inserted between } and !! (curly-spacing).

Changed

indent rule to allow "Method declaration parameters -> Align when multiline" (as this option is (unfortunately) "on" by default in Intellij IDEA) (#26).

0.4.0 - 2017-02-01

Fixed

NPE in case of "Permission denied" (while scanning the file system).

Changed

kotlin-compiler version to 1.1-M04 (from 1.0.6).

0.3.1 - 2017-01-25

Fixed

Unused infix function call import false positive (#25).

0.3.0 - 2017-01-11

Added

*.kts (script) support.

Changed

kotlin-compiler version to 1.0.6 (from 1.0.3).

0.2.2 - 2016-10-11

Fixed

no-wildcard-imports rule (kotlinx.android.synthetic excluded from check) (#16).

0.2.1 - 2016-09-13

Fixed

curly-spacing false negative in case of }?..

0.2.0 - 2016-09-05

Added

Support for 3rd party "ruleset"s.

Changed

ktlint -F output (it now includes lint errors that cannot be fixed automatically).

Fixed

ktlint -F --debug error count.
Glob implementation (previously it was prone to catastrophic backtracking).
Redundant semicolon false positive in case of enum (#12).
Unused operator import false positive (#13).

0.1.2 - 2016-08-05

Fixed

"in-use" escaped imports detection (#7) (no-unused-imports).

0.1.1 - 2016-08-01

Fixed

Incorrect spacing around curly braces (curly-spacing).

Files

CHANGELOG.md

Latest commit

History

CHANGELOG.md

File metadata and controls

Changelog

Unreleased

API changes

Custom rule providers

Added

Removed

Fixed

Changed

[0.50.0] - 2023-06-29

Deprecation of ktlint-enable and ktlint-disable directives

Custom Rule Providers need to prepare for Kotlin 1.9

Added

Removed

Fixed

Changed

0.49.1 - 2023-05-12

Added

Removed

Fixed

Changed

0.49.0 - 2023-04-21

Moving experimental rules to standard rule set

Promote experimental rules to non-experimental

API Changes & RuleSet providers & Reporter Providers

Experimental rules

EditorConfig

'Ktlint Official` code style and renaming of existing code styles

Package restructuring and class relocation

Custom Ruleset Provider RuleSetProviderV2

Custom Reporter Provider ReporterProvider

Custom rules provided by API Consumer

.editorconfig property max_line_length default value

Psi filename replaces FILE_PATH_USER_DATA_KEY

Added

Removed

Fixed

Changed

0.48.2 - 2023-01-21

Additional clarification on API Changes in 0.48.0 and 0.48.1

Added

Removed

Fixed

Changed

0.48.1 - 2023-01-03

Added

Removed

Fixed

Changed

0.48.0 - 2022-12-15

Indent rule

.editorconfig property to disable rules

API Changes & RuleSet providers

Class relocations

Invoking lint and format

Retrieve .editorconfigs

Psi filename replaces FILE_PATH_USER_DATA_KEY

Added

Fixed

Changed

0.47.1 - 2022-09-07

Fixed

Changed

0.47.0 - 2022-08-19

API Changes & RuleSet providers

Rule lifecycle hooks / deprecate RunOnRootOnly visitor modifier

Ruleset providing by Custom Rule Set Provider

Rule set providing by API Consumer

Format callback

CurrentBaseline

.editorconfig property "disabled_rules"

Default/alternative .editorconfig

Reload of .editorconfig file

Miscellaneous

Added

Custom Ruleset Provider `RuleSetProviderV2`

Custom Reporter Provider `ReporterProvider`

`.editorconfig` property `max_line_length` default value

Additional clarification on API Changes in `0.48.0` and `0.48.1`

`.editorconfig` property to disable rules

Invoking `lint` and `format`

Retrieve `.editorconfig`s

Reload of `.editorconfig` file