Add config generator for custom rules

detekt-generator/src/main/kotlin/io/gitlab/arturbosch/detekt/generator/DetektPrinter.kt

@@ -38,6 +38,12 @@ class DetektPrinter(private val arguments: GeneratorArgs) {
         }
     }
 
+    fun printCustomRuleConfig(pages: List<RuleSetPage>, folder: String) {
+        yamlWriter.write(Paths.get(folder), "config") {
+            ConfigPrinter.printCustomRuleConfig(pages)
+        }
+    }
+
     private fun markdownHeader(ruleSet: String): String {
         check(ruleSet.length > 1) { "Rule set name must be not empty or less than two symbols." }
         return """

detekt-generator/src/main/kotlin/io/gitlab/arturbosch/detekt/generator/Generator.kt

@@ -39,4 +39,34 @@ class Generator(
 
         outPrinter.println("\nGenerated all detekt documentation in $time ms.")
     }
+
+    fun executeCustomRuleConfig() {
+        val parser = KtCompiler()
+        val time = measureTimeMillis {
+            val ktFiles = arguments.inputPath
+                .flatMap { parseAll(parser, it) }
+
+            val folderMap = mutableMapOf<KtFile, String>()
+            ktFiles.forEach { ktFile ->
+                val pathParts = ktFile.name.split("/src/main/kotlin")
+                if (pathParts.count() > 1) {
+                    folderMap[ktFile] = "${pathParts.first()}/src/main/resources/config/"
+                }
+            }
+
+            folderMap
+                .toList()
+                .groupBy { (_, folder) -> folder }
+                .toList()
+                .forEach { (folder, list) ->
+                    val collector = DetektCollector()
+                    list.forEach { (file, _) ->
+                        collector.visit(file)
+                    }
+                    printer.printCustomRuleConfig(collector.items, folder)
+                }
+        }
+
+        outPrinter.println("\nGenerated custom rules config in $time ms.")
+    }
 }

detekt-generator/src/main/kotlin/io/gitlab/arturbosch/detekt/generator/GeneratorArgs.kt

@@ -16,21 +16,21 @@ class GeneratorArgs {
 
     @Parameter(
         names = ["--documentation", "-d"],
-        required = true,
+        required = false,
         description = "Output path for generated documentation."
     )
     private var documentation: String? = null
 
     @Parameter(
         names = ["--config", "-c"],
-        required = true,
+        required = false,
         description = "Output path for generated detekt config."
     )
     private var config: String? = null
 
     @Parameter(
         names = ["--cli-options"],
-        required = true,
+        required = false,
         description = "Output path for generated cli options page."
     )
     private var cliOptions: String? = null
@@ -42,6 +42,14 @@ class GeneratorArgs {
     )
     var help: Boolean = false
 
+    @Parameter(
+        names = ["--generate-custom-rule-config", "-gcrc"],
+        required = false,
+        description = "Generate config for user-defined rules. " +
+            "Path to user rules can be specified with --input option"
+    )
+    var generateCustomRuleConfig: Boolean = false
+
     val inputPath: List<Path> by lazy {
         checkNotNull(input) { "Input parameter was not initialized by jcommander!" }
             .splitToSequence(",", ";")

detekt-generator/src/main/kotlin/io/gitlab/arturbosch/detekt/generator/Main.kt

@@ -17,6 +17,11 @@ fun main(args: Array<String>) {
         exitProcess(0)
     }
 
+    if (options.generateCustomRuleConfig) {
+        Generator(options).executeCustomRuleConfig()
+        return
+    }
+
     require(Files.isDirectory(options.documentationPath)) { "Documentation path must be a directory." }
     require(Files.isDirectory(options.configPath)) { "Config path must be a directory." }
 

detekt-generator/src/main/kotlin/io/gitlab/arturbosch/detekt/generator/printer/defaultconfig/ConfigPrinter.kt

@@ -24,6 +24,13 @@ object ConfigPrinter : DocumentationPrinter<List<RuleSetPage>> {
         }
     }
 
+    fun printCustomRuleConfig(item: List<RuleSetPage>): String {
+        return yaml {
+            item.sortedBy { it.ruleSet.name }
+                .forEach { printRuleSetPage(it) }
+        }
+    }
+
     private fun defaultBuildConfiguration(): String = """
         build:
           maxIssues: 0

detekt-generator/src/test/kotlin/io/gitlab/arturbosch/detekt/generator/printer/GeneratorSpec.kt

@@ -0,0 +1,52 @@
+package io.gitlab.arturbosch.detekt.generator.printer
+
+import org.assertj.core.api.Assertions.assertThat
+import org.junit.jupiter.api.AfterAll
+import org.junit.jupiter.api.BeforeAll
+import org.junit.jupiter.api.Test
+import java.io.File
+import java.nio.file.Files
+import java.nio.file.Paths
+
+class GeneratorSpec {
+    @Test
+    fun `config files generated successfully`() {
+        assertThat(File("$folder1$configPath")).exists()
+        assertThat(File("$folder2$configPath")).exists()
+    }
+
+    @Test
+    fun `config files have proper content`() {
+        assertThat(File("$folder1$configPath").readText())
+            .contains("complexity:")
+            .doesNotContain("coroutines:")
+
+        assertThat(File("$folder2$configPath").readText())
+            .contains("coroutines:")
+            .doesNotContain("complexity:")
+    }
+
+    companion object {
+        private const val folder1 = "../detekt-rules-complexity"
+        private const val folder2 = "../detekt-rules-coroutines"
+        private const val configPath = "/src/main/resources/config/config.yml"
+
+        @JvmStatic
+        @BeforeAll
+        fun init() {
+            val args = arrayOf(
+                "--generate-custom-rule-config",
+                "--input",
+                "$folder1, $folder2",
+            )
+            io.gitlab.arturbosch.detekt.generator.main(args)
+        }
+
+        @JvmStatic
+        @AfterAll
+        fun tearDown() {
+            Files.deleteIfExists(Paths.get(folder1, configPath))
+            Files.deleteIfExists(Paths.get(folder2, configPath))
+        }
+    }
+}