Ensure Kotlin compilation task reruns when detekt config changes

detekt · Sep 12, 2020 · a1f64cf · a1f64cf
1 parent 5217b9b
commit a1f64cf
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diff --git a/src/main/kotlin/io/github/detekt/compiler/plugin/DetektCommandLineProcessor.kt b/src/main/kotlin/io/github/detekt/compiler/plugin/DetektCommandLineProcessor.kt
@@ -17,6 +17,12 @@ class DetektCommandLineProcessor : CommandLineProcessor {
             "Comma separated paths to detekt config files.",
             false
         ),
+        CliOption(
+            Options.configDigest,
+            "<digest>",
+            "A digest calculated from the content of the config files. Used for Gradle incremental task invalidation.",
+            false
+        ),
         CliOption(
             Options.baseline,
             "<path>",

diff --git a/src/main/kotlin/io/github/detekt/compiler/plugin/Keys.kt b/src/main/kotlin/io/github/detekt/compiler/plugin/Keys.kt
@@ -7,6 +7,7 @@ object Options {
     const val isEnabled: String = "isEnabled"
     const val debug: String = "debug"
     const val config = "config"
+    const val configDigest: String = "configDigest"
     const val baseline: String = "baseline"
     const val useDefaultConfig: String = "useDefaultConfig"
 }

diff --git a/src/main/kotlin/io/github/detekt/gradle/DetektKotlinCompilerPlugin.kt b/src/main/kotlin/io/github/detekt/gradle/DetektKotlinCompilerPlugin.kt
@@ -3,11 +3,15 @@ package io.github.detekt.gradle
 import io.github.detekt.compiler.plugin.Options
 import io.github.detekt.gradle.extensions.DetektExtension
 import org.gradle.api.Project
+import org.gradle.api.file.ConfigurableFileCollection
 import org.gradle.api.provider.Provider
 import org.jetbrains.kotlin.gradle.plugin.KotlinCompilation
 import org.jetbrains.kotlin.gradle.plugin.KotlinCompilerPluginSupportPlugin
 import org.jetbrains.kotlin.gradle.plugin.SubpluginArtifact
 import org.jetbrains.kotlin.gradle.plugin.SubpluginOption
+import java.io.File
+import java.security.MessageDigest
+import java.util.Base64
 
 class DetektKotlinCompilerPlugin : KotlinCompilerPluginSupportPlugin {
 
@@ -24,6 +28,7 @@ class DetektKotlinCompilerPlugin : KotlinCompilerPluginSupportPlugin {
 
         val options = project.objects.listProperty(SubpluginOption::class.java).apply {
             add(SubpluginOption(Options.debug, extension.debug.toString()))
+            add(SubpluginOption(Options.configDigest, extension.config.toDigest()))
             add(SubpluginOption(Options.isEnabled, extension.isEnabled.toString()))
             add(SubpluginOption(Options.useDefaultConfig, extension.buildUponDefaultConfig.toString()))
         }
@@ -36,6 +41,17 @@ class DetektKotlinCompilerPlugin : KotlinCompilerPluginSupportPlugin {
         return options
     }
 
+    private fun ConfigurableFileCollection.toDigest(): String {
+        val concatenatedConfig = this
+            .filter { it.isFile }
+            .map(File::readBytes)
+            .fold(byteArrayOf()) { acc, file -> acc + file }
+
+        return Base64.getEncoder().encodeToString(
+            MessageDigest.getInstance("SHA-256").digest(concatenatedConfig)
+        )
+    }
+
     override fun getCompilerPluginId(): String = DETEKT_COMPILER_PLUGIN
 
     override fun getPluginArtifact(): SubpluginArtifact =