Initial implementation of IDE integration via editorconfig

CHANGELOG.md

@@ -2,6 +2,20 @@
 All notable changes to this project will be documented in this file.  
 This project adheres to [Semantic Versioning](http://semver.org/).
 
+## Unreleased
+
+### Added
+- Initial implementation IDE integration via '.editorconfig' based on rules default values ([#701](https://github.com/pinterest/ktlint/issues/701))
+
+### Fixed
+- ?
+
+### Changed
+- ?
+
+### Removed
+- ?
+
 ## [0.39.0] - 2020-09-14
 
 ### Added

build.gradle

@@ -68,6 +68,8 @@ allprojects {
     kotlinOptions {
       jvmTarget = '1.8'
       apiVersion = '1.3'
+
+      freeCompilerArgs = ["-Xopt-in=kotlin.RequiresOptIn"]
     }
   }
 }

ktlint-core/build.gradle

@@ -7,7 +7,7 @@ dependencies {
   api deps.kotlin.compiler
 
   implementation deps.kotlin.stdlib
-  implementation deps.ec4j
+  api deps.ec4j
 
   testImplementation deps.junit
   testImplementation deps.assertj

ktlint-core/src/main/kotlin/com/pinterest/ktlint/core/EditorConfig.kt

@@ -13,8 +13,12 @@ interface EditorConfig {
     val indentSize: Int
     val tabWidth: Int
     val maxLineLength: Int
+    @Deprecated(
+        message = "Not used anymore by rules, please use 'insert_final_newline' directly via get()"
+    )
     val insertFinalNewline: Boolean
-    fun get(key: String): String?
+
+    operator fun get(key: String): String?
 
     companion object {
         fun fromMap(map: Map<String, String>): EditorConfig {

ktlint-core/src/main/kotlin/com/pinterest/ktlint/core/KtLint.kt

@@ -1,7 +1,11 @@
 package com.pinterest.ktlint.core
 
+import com.pinterest.ktlint.core.api.EditorConfigProperties
+import com.pinterest.ktlint.core.api.FeatureInAlphaState
 import com.pinterest.ktlint.core.ast.visit
+import com.pinterest.ktlint.core.internal.EditorConfigGenerator
 import com.pinterest.ktlint.core.internal.EditorConfigLoader
+import com.pinterest.ktlint.core.internal.EditorConfigLoader.Companion.convertToRawValues
 import com.pinterest.ktlint.core.internal.LineAndColumn
 import com.pinterest.ktlint.core.internal.SuppressionLocator
 import com.pinterest.ktlint.core.internal.buildPositionInTextLocator
@@ -25,13 +29,18 @@ public object KtLint {
     public val EDITOR_CONFIG_USER_DATA_KEY: Key<EditorConfig> = Key<EditorConfig>("EDITOR_CONFIG")
     public val ANDROID_USER_DATA_KEY: Key<Boolean> = Key<Boolean>("ANDROID")
     public val FILE_PATH_USER_DATA_KEY: Key<String> = Key<String>("FILE_PATH")
+    public val EDITOR_CONFIG_PROPERTIES_USER_DATA_KEY: Key<EditorConfigProperties> =
+        Key<EditorConfigProperties>("EDITOR_CONFIG_PROPERTIES")
     public val DISABLED_RULES: Key<Set<String>> = Key<Set<String>>("DISABLED_RULES")
     private const val UTF8_BOM = "\uFEFF"
     public const val STDIN_FILE: String = "<stdin>"
 
     private val psiFileFactory: PsiFileFactory = initPsiFileFactory()
     private val editorConfigLoader = EditorConfigLoader(FileSystems.getDefault())
 
+    @OptIn(FeatureInAlphaState::class)
+    private val editorConfigGenerator = EditorConfigGenerator(editorConfigLoader)
+
     /**
      * @param fileName path of file to lint/format
      * @param text Contents of file to lint/format
@@ -59,6 +68,12 @@ public object KtLint {
         }
 
         internal val isStdIn: Boolean get() = fileName == STDIN_FILE
+
+        internal val rules: Set<Rule> get() = ruleSets
+            .flatMap {
+                it.rules.toList()
+            }
+            .toSet()
     }
 
     /**
@@ -121,14 +136,21 @@ public object KtLint {
 
         val rootNode = psiFile.node
 
-        // Passed-in userData overrides .editorconfig
-        val mergedUserData = editorConfigLoader.loadPropertiesForFile(
+        val editorConfigProperties = editorConfigLoader.loadPropertiesForFile(
             params.normalizedFilePath,
             params.isStdIn,
             params.editorConfigPath?.let { Paths.get(it) },
+            params.rules,
             params.debug
+        )
+
+        // Passed-in userData overrides .editorconfig
+        val mergedUserData = editorConfigProperties.convertToRawValues(
+            params.normalizedFilePath,
+            params.isStdIn
         ) + params.userData
-        injectUserData(rootNode, mergedUserData)
+
+        injectUserData(rootNode, editorConfigProperties, mergedUserData)
 
         val suppressedRegionLocator = buildSuppressedRegionsLocator(rootNode)
 
@@ -150,7 +172,11 @@ public object KtLint {
             .replaceFirst(UTF8_BOM, "")
     }
 
-    private fun injectUserData(node: ASTNode, userData: Map<String, String>) {
+    private fun injectUserData(
+        node: ASTNode,
+        editorConfigProperties: EditorConfigProperties,
+        userData: Map<String, String>
+    ) {
         val android = userData["android"]?.toBoolean() ?: false
         val editorConfigMap =
             if (android &&
@@ -162,6 +188,7 @@ public object KtLint {
             }
         node.putUserData(FILE_PATH_USER_DATA_KEY, userData["file_path"])
         node.putUserData(EDITOR_CONFIG_USER_DATA_KEY, EditorConfig.fromMap(editorConfigMap - "android" - "file_path"))
+        node.putUserData(EDITOR_CONFIG_PROPERTIES_USER_DATA_KEY, editorConfigProperties)
         node.putUserData(ANDROID_USER_DATA_KEY, android)
         node.putUserData(
             DISABLED_RULES,
@@ -336,6 +363,36 @@ public object KtLint {
         editorConfigLoader.trimMemory()
     }
 
+    /**
+     * Generates Kotlin `.editorconfig` file section content based on [Params.ruleSets].
+     *
+     * Method loads merged `.editorconfig` content from [Params.fileName] path,
+     * and then, by querying rules from [Params.ruleSets] for missing properties default values,
+     * generates Kotlin section (default is `[*.{kt,kts}]`) new content.
+     *
+     * Rule should implement [UsesEditorConfigProperties] interface to support this.
+     *
+     * @return Kotlin section editorconfig content. For example:
+     * ```properties
+     * final-newline=true
+     * indent-size=4
+     * ```
+     */
+    @FeatureInAlphaState
+    public fun generateKotlinEditorConfigSection(
+        params: Params
+    ): String {
+        val filePath = params.normalizedFilePath
+        requireNotNull(filePath) {
+            "Please pass path to existing Kotlin file"
+        }
+        return editorConfigGenerator.generateEditorconfig(
+            filePath,
+            params.rules,
+            params.debug
+        )
+    }
+
     private fun determineLineSeparator(fileContent: String, userData: Map<String, String>): String {
         val eol = userData["end_of_line"]?.trim()?.toLowerCase()
         return when {

ktlint-core/src/main/kotlin/com/pinterest/ktlint/core/api/OptInFeatures.kt

@@ -0,0 +1,17 @@
+package com.pinterest.ktlint.core.api
+
+@RequiresOptIn(
+    message = "This Ktlint feature is highly experimental, and most probably will change in the future releases.",
+    level = RequiresOptIn.Level.ERROR
+)
+@Retention(AnnotationRetention.BINARY)
+@Target(AnnotationTarget.CLASS, AnnotationTarget.FUNCTION)
+public annotation class FeatureInAlphaState
+
+@RequiresOptIn(
+    message = "This Ktlint feature is experimental, and may change in the future releases.",
+    level = RequiresOptIn.Level.WARNING
+)
+@Retention(AnnotationRetention.BINARY)
+@Target(AnnotationTarget.CLASS, AnnotationTarget.FUNCTION)
+public annotation class FeatureInBetaState

ktlint-core/src/main/kotlin/com/pinterest/ktlint/core/api/UsesEditorConfigProperties.kt

@@ -0,0 +1,52 @@
+package com.pinterest.ktlint.core.api
+
+import org.ec4j.core.model.Property
+import org.ec4j.core.model.PropertyType
+
+/**
+ * Indicates [com.pinterest.ktlint.core.Rule] uses properties loaded from `.editorconfig` file.
+ *
+ * This properties could be:
+ * - universal `.editorconfig` properties defined
+ * [here](https://github.com/editorconfig/editorconfig/wiki/EditorConfig-Properties#current-universal-properties)
+ * - universal IntelliJ IDEA properties defined
+ * [here](https://github.com/JetBrains/intellij-community/blob/master/platform/lang-api/src/com/intellij/psi/codeStyle/CommonCodeStyleSettings.java)
+ * - Kotlin specific properties defined
+ * [here](https://github.com/JetBrains/kotlin/blob/master/idea/formatter/src/org/jetbrains/kotlin/idea/core/formatter/KotlinCodeStyleSettings.java)
+ *
+ * In the best case rule should only use one property.
+ *
+ * See [com.pinterest.ktlint.core.KtLint.generateKotlinEditorConfigSection] documentation how to generate
+ * `.editorconfig` based on [com.pinterest.ktlint.core.Rule]s with this interface implementations.
+ */
+@FeatureInAlphaState
+public interface UsesEditorConfigProperties {
+
+    /**
+     * Provide a list of code style editorconfig properties, that rule uses in linting.
+     */
+    public val editorConfigProperties: List<EditorConfigProperty<*>>
+
+    /**
+     * Get the value of [EditorConfigProperty] based on loaded [EditorConfigProperties] content.
+     */
+    public fun <T> EditorConfigProperties.getEditorConfigValue(property: EditorConfigProperty<T>): T {
+        return get(property.type.name)?.getValueAs() ?: property.defaultValue
+    }
+
+    /**
+     * Supported `.editorconfig` property.
+     *
+     * @param type type of property. Could be one of default ones (see [PropertyType.STANDARD_TYPES]) or custom one.
+     * @param defaultValue default value for property if it does not exist in loaded properties.
+     */
+    public data class EditorConfigProperty<T>(
+        public val type: PropertyType<T>,
+        public val defaultValue: T
+    )
+}
+
+/**
+ * Loaded [Property]s from `.editorconfig` files.
+ */
+public typealias EditorConfigProperties = Map<String, Property>

ktlint-core/src/main/kotlin/com/pinterest/ktlint/core/internal/EditorConfigGenerator.kt

@@ -0,0 +1,58 @@
+package com.pinterest.ktlint.core.internal
+
+import com.pinterest.ktlint.core.Rule
+import com.pinterest.ktlint.core.api.FeatureInAlphaState
+import com.pinterest.ktlint.core.api.UsesEditorConfigProperties
+import java.nio.file.Path
+import org.ec4j.core.model.Property
+
+/**
+ * Generates Kotlin section content for `.editorconfig` file.
+ *
+ * Rule should implement [UsesEditorConfigProperties] interface to support this.
+ */
+@FeatureInAlphaState
+internal class EditorConfigGenerator(
+    private val editorConfigLoader: EditorConfigLoader
+) {
+    /**
+     * Method loads merged `.editorconfig` content using [com.pinterest.ktlint.core.KtLint.Params.fileName] path,
+     * and then, by querying rules from [com.pinterest.ktlint.core.KtLint.Params.ruleSets]
+     * generates Kotlin section (default is `[*.{kt,kts}]`) content including expected default values.
+     *
+     * @return Kotlin section editorconfig content. For example:
+     * ```properties
+     * final-newline = true
+     * indent-size = 4
+     * ```
+     */
+    fun generateEditorconfig(
+        filePath: Path,
+        rules: Set<Rule>,
+        debug: Boolean = false
+    ): String {
+        val editorConfig: Map<String, Property> = editorConfigLoader.loadPropertiesForFile(
+            filePath = filePath,
+            rules = rules,
+            debug = debug
+        )
+
+        return rules
+            .fold(mutableMapOf<String, String?>()) { acc, rule ->
+                if (rule is UsesEditorConfigProperties) {
+                    if (debug) println("Checking properties for '${rule.id}' rule")
+                    rule.editorConfigProperties.forEach { prop ->
+                        if (debug) println("Setting '${prop.type.name}' property value")
+                        acc[prop.type.name] = with(rule) { editorConfig.getEditorConfigValue(prop).toString() }
+                    }
+                }
+
+                acc
+            }
+            .filterValues { it != null }
+            .map {
+                "${it.key} = ${it.value}"
+            }
+            .joinToString(separator = System.lineSeparator())
+    }
+}