Merge pull request #790 from square/lazily_evaluate_dependency_guard_configs

Support late/lazy configuration creation in dependency guard

Author: RBusarow

buildSrc/src/main/java/dependency-guard.gradle.kts

@@ -1,31 +1,38 @@
 import com.android.build.gradle.TestedExtension
 import com.dropbox.gradle.plugins.dependencyguard.DependencyGuardPluginExtension
 
-val configurationNames = when {
-  // record the root project's *build* classpath
-  project == rootProject -> listOf("classpath")
-  // Android variants and their configurations are added later in the configuration phase,
-  // so we can't look them up now using the `configurations` property.
-  // Instead we can just hard-code "releaseRuntimeClasspath" for any module which has AGP applied.
-  // This is actually pretty robust, since if this configuration ever changes,
-  // dependency-guard will fail when trying to look it up.
-  extensions.findByType<TestedExtension>() != null -> listOf("releaseRuntimeClasspath")
-  // If we got here, we're either in an empty "parent" module without a build plugin
-  // (and no configurations), or we're in a vanilla Kotlin module.  In this case, we can just look
-  // at configuration names.
-  else -> configurations
-    .map { it.name }
-    // anything ending with 'runtimeClasspath' but not 'testRuntimeClasspath'
-    .filter { it.matches("^(?!test)\\w*[rR]untimeClasspath$".toRegex()) }
-}
+// We have to use `afterEvaluate { ... }` because both KMP and AGP create their configurations later
+// in the configuration phase.  If we were to try looking up those configurations eagerly as soon
+// as this convention plugin is applied, there would be nothing there.
+afterEvaluate {
+  val configurationNames = when {
+    // record the root project's *build* classpath
+    project == rootProject -> listOf("classpath")
+
+    // For Android modules, just hard-code `releaseRuntimeClasspath` for the release variant.
+    // This is actually pretty robust, since if this configuration ever changes, dependency-guard
+    // will fail when trying to look it up.
+    extensions.findByType<TestedExtension>() != null -> listOf("releaseRuntimeClasspath")
+
+    // If we got here, we're either in an empty "parent" module without a build plugin
+    // (and no configurations), or we're in a vanilla Kotlin module.  In this case, we can just look
+    // at configuration names.
+    else -> configurations
+      .map { it.name }
+      .filter {
+        it.endsWith("runtimeClasspath", ignoreCase = true) &&
+          !it.endsWith("testRuntimeClasspath", ignoreCase = true)
+      }
+  }
 
-if (configurationNames.isNotEmpty()) {
-  apply(plugin = "com.dropbox.dependency-guard")
+  if (configurationNames.isNotEmpty()) {
+    apply(plugin = "com.dropbox.dependency-guard")
 
-  configure<DependencyGuardPluginExtension> {
-    configurationNames.forEach { configName ->
-      // Tell dependency-guard to check the `configName` configuration's dependencies.
-      configuration(configName)
+    configure<DependencyGuardPluginExtension> {
+      configurationNames.forEach { configName ->
+        // Tell dependency-guard to check the `configName` configuration's dependencies.
+        configuration(configName)
+      }
     }
   }
 }