Add 'generateEditorConfig' CLI subcommand.

CHANGELOG.md

@@ -6,6 +6,7 @@ This project adheres to [Semantic Versioning](http://semver.org/).
 
 ### Added
 - Initial implementation IDE integration via '.editorconfig' based on rules default values ([#701](https://github.com/pinterest/ktlint/issues/701))
+- CLI subcommand `generateEditorConfig` to generate '.editorconfig' content for Kotlin files ([#701](https://github.com/pinterest/ktlint/issues/701))
 
 ### Fixed
 - ?

ktlint/src/main/kotlin/com/pinterest/ktlint/Main.kt

@@ -11,16 +11,18 @@ import com.pinterest.ktlint.core.RuleExecutionException
 import com.pinterest.ktlint.core.RuleSetProvider
 import com.pinterest.ktlint.internal.ApplyToIDEAGloballySubCommand
 import com.pinterest.ktlint.internal.ApplyToIDEAProjectSubCommand
+import com.pinterest.ktlint.internal.GenerateEditorConfigSubCommand
 import com.pinterest.ktlint.internal.GitPreCommitHookSubCommand
 import com.pinterest.ktlint.internal.GitPrePushHookSubCommand
 import com.pinterest.ktlint.internal.KtlintVersionProvider
 import com.pinterest.ktlint.internal.PrintASTSubCommand
-import com.pinterest.ktlint.internal.expandTilde
 import com.pinterest.ktlint.internal.fileSequence
 import com.pinterest.ktlint.internal.formatFile
 import com.pinterest.ktlint.internal.lintFile
+import com.pinterest.ktlint.internal.loadRulesets
 import com.pinterest.ktlint.internal.location
 import com.pinterest.ktlint.internal.printHelpOrVersionUsage
+import com.pinterest.ktlint.internal.toFilesURIList
 import com.pinterest.ktlint.reporter.plain.internal.Color
 import java.io.File
 import java.io.IOException
@@ -52,6 +54,7 @@ fun main(args: Array<String>) {
         .addSubcommand(PrintASTSubCommand.COMMAND_NAME, PrintASTSubCommand())
         .addSubcommand(ApplyToIDEAGloballySubCommand.COMMAND_NAME, ApplyToIDEAGloballySubCommand())
         .addSubcommand(ApplyToIDEAProjectSubCommand.COMMAND_NAME, ApplyToIDEAProjectSubCommand())
+        .addSubcommand(GenerateEditorConfigSubCommand.COMMAND_NAME, GenerateEditorConfigSubCommand())
     val parseResult = commandLine.parseArgs(*args)
 
     commandLine.printHelpOrVersionUsage()
@@ -73,6 +76,7 @@ fun handleSubCommand(
         is PrintASTSubCommand -> subCommand.run()
         is ApplyToIDEAGloballySubCommand -> subCommand.run()
         is ApplyToIDEAProjectSubCommand -> subCommand.run()
+        is GenerateEditorConfigSubCommand -> subCommand.run()
         else -> commandLine.usage(System.out, CommandLine.Help.Ansi.OFF)
     }
 }
@@ -181,7 +185,7 @@ class KtlintCommandLine {
         names = ["--ruleset", "-R"],
         description = ["A path to a JAR file containing additional ruleset(s)"]
     )
-    private var rulesets = ArrayList<String>()
+    var rulesets = ArrayList<String>()
 
     @Option(
         names = ["--stdin"],
@@ -205,7 +209,7 @@ class KtlintCommandLine {
         names = ["--experimental"],
         description = ["Enabled experimental rules (ktlint-ruleset-experimental)"]
     )
-    private var experimental: Boolean = false
+    var experimental: Boolean = false
 
     @Parameters(hidden = true)
     private var patterns = ArrayList<String>()
@@ -219,7 +223,7 @@ class KtlintCommandLine {
 
         val start = System.currentTimeMillis()
 
-        val ruleSetProviders = loadRulesets(rulesets)
+        val ruleSetProviders = rulesets.loadRulesets(experimental, debug)
         val reporter = loadReporter()
         val userData = listOfNotNull(
             "android" to android.toString(),
@@ -541,26 +545,6 @@ class KtlintCommandLine {
         }
     }
 
-    private fun loadRulesets(externalRulesetsJarPaths: List<String>) = ServiceLoader
-        .load(
-            RuleSetProvider::class.java,
-            URLClassLoader(externalRulesetsJarPaths.toFilesURIList().toTypedArray())
-        )
-        .associateBy {
-            val key = it.get().id
-            // standard should go first
-            if (key == "standard") "\u0000$key" else key
-        }
-        .filterKeys { experimental || it != "experimental" }
-        .toSortedMap()
-        .also {
-            if (debug) {
-                it.forEach { entry ->
-                    println("[DEBUG] Discovered ruleset with \"${entry.key}\" id.")
-                }
-            }
-        }
-
     private fun loadReporters(externalReportersJarPaths: List<String>) = ServiceLoader
         .load(
             ReporterProvider::class.java,
@@ -575,15 +559,6 @@ class KtlintCommandLine {
             }
         }
 
-    private fun List<String>.toFilesURIList() = map {
-        val jarFile = File(expandTilde(it))
-        if (!jarFile.exists()) {
-            println("Error: $it does not exist")
-            exitProcess(1)
-        }
-        jarFile.toURI().toURL()
-    }
-
     private data class LintErrorWithCorrectionInfo(
         val err: LintError,
         val corrected: Boolean

ktlint/src/main/kotlin/com/pinterest/ktlint/internal/FileUtils.kt

@@ -7,6 +7,7 @@ import com.pinterest.ktlint.core.RuleSet
 import java.io.File
 import java.nio.file.Path
 import java.nio.file.Paths
+import kotlin.system.exitProcess
 
 internal val workDir: String = File(".").canonicalPath
 
@@ -28,9 +29,18 @@ internal fun List<String>.fileSequence(): Sequence<File> {
         .map(Path::toFile)
 }
 
+internal fun List<String>.toFilesURIList() = map {
+    val jarFile = File(expandTilde(it))
+    if (!jarFile.exists()) {
+        println("Error: $it does not exist")
+        exitProcess(1)
+    }
+    jarFile.toURI().toURL()
+}
+
 // a complete solution would be to implement https://www.gnu.org/software/bash/manual/html_node/Tilde-Expansion.html
 // this implementation takes care only of the most commonly used case (~/)
-internal fun expandTilde(path: String): String = path.replaceFirst(Regex("^~"), System.getProperty("user.home"))
+private fun expandTilde(path: String): String = path.replaceFirst(Regex("^~"), System.getProperty("user.home"))
 
 internal fun File.location(
     relative: Boolean

ktlint/src/main/kotlin/com/pinterest/ktlint/internal/GenerateEditorConfigSubCommand.kt

@@ -0,0 +1,58 @@
+package com.pinterest.ktlint.internal
+
+import com.pinterest.ktlint.KtlintCommandLine
+import com.pinterest.ktlint.core.KtLint
+import com.pinterest.ktlint.core.api.FeatureInAlphaState
+import picocli.CommandLine
+
+@CommandLine.Command(
+    description = [
+        "EXPERIMENTAL!!! Generate kotlin style section for '.editorconfig' file.",
+        "Add output content into '.editorconfig' file"
+    ],
+    mixinStandardHelpOptions = true,
+    versionProvider = KtlintVersionProvider::class
+)
+class GenerateEditorConfigSubCommand : Runnable {
+    @CommandLine.ParentCommand
+    private lateinit var ktlintCommand: KtlintCommandLine
+
+    @CommandLine.Spec
+    private lateinit var commandSpec: CommandLine.Model.CommandSpec
+
+    @OptIn(FeatureInAlphaState::class)
+    override fun run() {
+        commandSpec.commandLine().printHelpOrVersionUsage()
+
+        // For now we are using CLI invocation dir as path to load existing '.editorconfig'
+        val generatedEditorConfig = KtLint.generateKotlinEditorConfigSection(
+            KtLint.Params(
+                fileName = "./test.kt",
+                text = "",
+                ruleSets = ktlintCommand.rulesets
+                    .loadRulesets(
+                        ktlintCommand.experimental,
+                        ktlintCommand.debug
+                    )
+                    .map { it.value.get() },
+                debug = ktlintCommand.debug,
+                cb = { _, _ -> Unit }
+            )
+        )
+
+        if (generatedEditorConfig.isNotBlank()) {
+            println(
+                """
+                [*.{kt,kts}]
+                $generatedEditorConfig
+                """.trimIndent()
+            )
+        } else {
+            println("Nothing to add to .editorconfig file")
+        }
+    }
+
+    companion object {
+        internal const val COMMAND_NAME = "generateEditorConfig"
+    }
+}

ktlint/src/main/kotlin/com/pinterest/ktlint/internal/RuleSetsLoader.kt

@@ -0,0 +1,33 @@
+package com.pinterest.ktlint.internal
+
+import com.pinterest.ktlint.core.RuleSetProvider
+import java.net.URLClassLoader
+import java.util.ServiceLoader
+
+/**
+ * Load given list of paths to rulesets jars into map of ruleset providers.
+ *
+ * @return map of ruleset ids to ruleset providers
+ */
+internal fun List<String>.loadRulesets(
+    loadExperimental: Boolean,
+    debug: Boolean
+) = ServiceLoader
+    .load(
+        RuleSetProvider::class.java,
+        URLClassLoader(this.toFilesURIList().toTypedArray())
+    )
+    .associateBy {
+        val key = it.get().id
+        // standard should go first
+        if (key == "standard") "\u0000$key" else key
+    }
+    .filterKeys { loadExperimental || it != "experimental" }
+    .toSortedMap()
+    .also {
+        if (debug) {
+            it.forEach { entry ->
+                println("[DEBUG] Discovered ruleset with \"${entry.key}\" id.")
+            }
+        }
+    }