Improve filtering of generated code in the coverage reports

.agents/skills/bump-version/SKILL.md

@@ -24,7 +24,9 @@ under these constraints:
 - Stage only `version.gradle.kts`. Any other modified files are out of scope
   for this skill's commit and must remain unstaged.
 - Use the exact subject `` Bump version -> `<new>` `` (see step 4 of the
-  Checklist) with the actual new version value substituted.
+  Checklist) with the actual new version value substituted. Keep the
+  backticks around the version literal (for example, ``... -> `2.0.0``` ) and
+  do not escape them as ``\````.
 - No `git push`, `git tag`, `git rebase`, `git commit --amend`, or any other
   history-writing operation. Those require a separate authorization
   (`.agents/safety-rules.md` → *Commits and history-writing*).
@@ -81,6 +83,12 @@ create the commit.
    Bump version -> `2.0.0-SNAPSHOT.183`
    ```
 
+   Shell-safe example (no escaped backticks in the commit subject):
+
+   ```bash
+   git commit -m 'Bump version -> `2.0.0-SNAPSHOT.183`' -- version.gradle.kts
+   ```
+
    Use the actual new version in the subject. Do not include unrelated files in
    this commit.
 

buildSrc/src/main/kotlin/io/spine/dependency/local/CoreJvmCompiler.kt

@@ -46,12 +46,12 @@ object CoreJvmCompiler {
     /**
      * The version used in the build classpath.
      */
-    const val dogfoodingVersion = "2.0.0-SNAPSHOT.065"
+    const val dogfoodingVersion = "2.0.0-SNAPSHOT.067"
 
     /**
      * The version to be used for integration tests.
      */
-    const val version = "2.0.0-SNAPSHOT.065"
+    const val version = "2.0.0-SNAPSHOT.067"
 
     /**
      * The ID of the Gradle plugin.

buildSrc/src/main/kotlin/io/spine/dependency/local/Validation.kt

@@ -36,7 +36,7 @@ object Validation {
     /**
      * The version of the Validation library artifacts.
      */
-    const val version = "2.0.0-SNAPSHOT.444"
+    const val version = "2.0.0-SNAPSHOT.445"
 
     /**
      * The last version of Validation compatible with ProtoData.

buildSrc/src/main/kotlin/io/spine/gradle/report/coverage/CodebaseFilter.kt

@@ -1,5 +1,5 @@
 /*
- * Copyright 2025, TeamDev. All rights reserved.
+ * Copyright 2026, TeamDev. All rights reserved.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -35,8 +35,8 @@ import org.gradle.api.file.FileTree
 import org.gradle.api.tasks.SourceSetOutput
 
 /**
- * Serves to distinguish the `.java` and `.class` files built on top of the Protobuf definitions
- * from the human-created production code.
+ * Serves to distinguish the generated `.java` and `.kt` files (and the `.class` files
+ * compiled from them) from the human-created production code.
  *
  * Works on top of the passed [source][srcDirs] and [output][outputDirs] directories, by analyzing
  * the source file names and finding the corresponding compiler output.
@@ -70,26 +70,15 @@ internal class CodebaseFilter(
         return humanProducedTree
     }
 
-    private fun generatedClassNames(): List<String> {
-        val generatedSourceFiles = generatedOnly(srcDirs)
-        val generatedNames = mutableListOf<String>()
-        generatedSourceFiles
+    private fun generatedClassNames(): List<String> =
+        generatedOnly(srcDirs)
             .filter { it.exists() && it.isDirectory }
-            .forEach { folder ->
-                folder.walk()
+            .flatMap { root ->
+                root.walk()
                     .filter { !it.isDirectory }
-                    .forEach { file ->
-                        file.parseName(
-                            File::asJavaClassName,
-                            File::asGrpcClassName,
-                            File::asSpineClassName
-                        )?.let { clsName ->
-                            generatedNames.add(clsName)
-                        }
-                    }
+                    .flatMap { it.classNamesIn(root) }
+                    .toList()
             }
-        return generatedNames
-    }
 
     private fun log(message: String) {
         project.logger.info(message)

buildSrc/src/main/kotlin/io/spine/gradle/report/coverage/FileExtension.kt

@@ -1,5 +1,5 @@
 /*
- * Copyright 2025, TeamDev. All rights reserved.
+ * Copyright 2026, TeamDev. All rights reserved.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -36,6 +36,11 @@ internal enum class FileExtension(val value: String) {
      */
     JAVA_SOURCE(".java"),
 
+    /**
+     * Extension of a Kotlin source file.
+     */
+    KOTLIN_SOURCE(".kt"),
+
     /**
      * Extension of a Java compiled file.
      */

buildSrc/src/main/kotlin/io/spine/gradle/report/coverage/FileExtensions.kt

@@ -1,5 +1,5 @@
 /*
- * Copyright 2025, TeamDev. All rights reserved.
+ * Copyright 2026, TeamDev. All rights reserved.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -20,32 +20,42 @@
  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF TE USE
  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
 package io.spine.gradle.report.coverage
 
 import io.spine.gradle.report.coverage.FileExtension.COMPILED_CLASS
 import io.spine.gradle.report.coverage.FileExtension.JAVA_SOURCE
+import io.spine.gradle.report.coverage.FileExtension.KOTLIN_SOURCE
 import io.spine.gradle.report.coverage.PathMarker.ANONYMOUS_CLASS
 import io.spine.gradle.report.coverage.PathMarker.GENERATED
-import io.spine.gradle.report.coverage.PathMarker.GRPC_SRC_FOLDER
-import io.spine.gradle.report.coverage.PathMarker.JAVA_OUTPUT_FOLDER
-import io.spine.gradle.report.coverage.PathMarker.JAVA_SRC_FOLDER
-import io.spine.gradle.report.coverage.PathMarker.SPINE_JAVA_SRC_FOLDER
+import io.spine.gradle.report.coverage.PathMarker.MAIN_OUTPUT_FOLDER
 import java.io.File
 
 /**
  * This file contains extension methods and properties for `java.io.File`.
  */
 
+/**
+ * The two-part extension used by `protoc-gen-kotlin` for proto-file-scoped Kotlin
+ * helpers (e.g., `FooProtoKt.proto.kt`).
+ */
+private const val PROTO_KOTLIN_SUFFIX = ".proto.kt"
+
+/**
+ * Suffix that the Kotlin compiler appends to the file name when generating the
+ * synthetic file class for top-level declarations.
+ */
+private const val KOTLIN_FILE_CLASS_SUFFIX = "Kt"
+
 /**
  * Parses the name of a class from the absolute path of this file.
  *
  * Treats the fragment between the [precedingMarker] and [extension] as the value to look for.
  * In case the fragment is located and it contains `/` symbols, they are treated
- * as Java package delimiters and are replaced by `.` symbols before returning the value.
+ * as package delimiters and are replaced by `.` symbols before returning the value.
  *
  * If the absolute path of this file has either no [precedingMarker] or no [extension],
  * returns `null`.
@@ -69,58 +79,59 @@ internal fun File.parseClassName(
 }
 
 /**
- * Attempts to parse the file name with either of the specified [parsers],
- * in their respective order.
- *
- * Returns the first non-`null` parsed value.
+ * Attempts to parse the fully-qualified class name from the absolute path of this file,
+ * treating it as a path to a compiled `.class` file produced by either `javac` or `kotlinc`.
  *
- * If none of the parsers returns non-`null` value, returns `null`.
- */
-internal fun File.parseName(vararg parsers: (file: File) -> String?): String? {
-    for (parser in parsers) {
-        val className = parser.invoke(this)
-        if (className != null) {
-            return className
-        }
-    }
-    return null
-}
-
-/**
- * Attempts to parse the Java fully-qualified class name from the absolute path of this file,
- * treating it as a path to a human-produced `.java` file.
- */
-internal fun File.asJavaClassName(): String? =
-    this.parseClassName(JAVA_SRC_FOLDER, JAVA_SOURCE)
-
-/**
- * Attempts to parse the Java fully-qualified class name from the absolute path of this file,
- * treating it as a path to a compiled `.class` file.
- *
- * If the `.class` file corresponds to the anonymous class, only the name of the parent
- * class is returned.
+ * If the `.class` file corresponds to the anonymous or nested class, only the name of the
+ * top-level enclosing class is returned.
  */
 internal fun File.asJavaCompiledClassName(): String? {
-    var className = this.parseClassName(JAVA_OUTPUT_FOLDER, COMPILED_CLASS)
+    var className = this.parseClassName(MAIN_OUTPUT_FOLDER, COMPILED_CLASS)
     if (className != null && className.contains(ANONYMOUS_CLASS.infix)) {
         className = className.split(ANONYMOUS_CLASS.infix)[0]
     }
     return className
 }
 
 /**
- * Attempts to parse the Java fully-qualified class name from the absolute path of this file,
- * treating it as a path to a gRPC-generated `.java` file.
+ * Returns the fully-qualified names of compiled JVM classes that originate from this
+ * source file, assuming [sourceRoot] is the source-set root under which the file was
+ * discovered.
+ *
+ * The shape of the returned list depends on the source file extension:
+ *
+ *  - `.java` — a single FQN derived from the path relative to [sourceRoot].
+ *  - `.kt` — two FQNs: the declared file/class name, and the same name with `Kt`
+ *    appended, which is the synthetic file class that Kotlin emits for top-level
+ *    declarations.
+ *  - `.proto.kt` — the two-part extension is stripped first; otherwise behaves
+ *    like `.kt`. This is the convention used by `protoc-gen-kotlin` for files
+ *    holding proto-file-scoped helpers.
+ *  - Any other extension — an empty list.
+ *
+ * Returns an empty list if this file is not located under [sourceRoot].
  */
-internal fun File.asGrpcClassName(): String? =
-    this.parseClassName(GRPC_SRC_FOLDER, JAVA_SOURCE)
+internal fun File.classNamesIn(sourceRoot: File): List<String> {
+    if (!this.startsWith(sourceRoot)) {
+        return emptyList()
+    }
+    val relative = this.toRelativeString(sourceRoot)
+    return when {
+        relative.endsWith(PROTO_KOTLIN_SUFFIX) -> {
+            val base = relative.removeSuffix(PROTO_KOTLIN_SUFFIX).toFqn()
+            listOf(base, base + KOTLIN_FILE_CLASS_SUFFIX)
+        }
+        relative.endsWith(KOTLIN_SOURCE.value) -> {
+            val base = relative.removeSuffix(KOTLIN_SOURCE.value).toFqn()
+            listOf(base, base + KOTLIN_FILE_CLASS_SUFFIX)
+        }
+        relative.endsWith(JAVA_SOURCE.value) ->
+            listOf(relative.removeSuffix(JAVA_SOURCE.value).toFqn())
+        else -> emptyList()
+    }
+}
 
-/**
- * Attempts to parse the Java fully-qualified class name from the absolute path of this file,
- * treating it as a path to a Spine-generated `.java` file.
- */
-internal fun File.asSpineClassName(): String? =
-    this.parseClassName(SPINE_JAVA_SRC_FOLDER, JAVA_SOURCE)
+private fun String.toFqn(): String = this.replace(File.separatorChar, '.')
 
 /**
  * Tells whether this file is a part of the generated sources, and not produced by a human.

buildSrc/src/main/kotlin/io/spine/gradle/report/coverage/JacocoConfig.kt

@@ -38,6 +38,7 @@ import java.io.File
 import java.util.*
 import org.gradle.api.Project
 import org.gradle.api.file.ConfigurableFileCollection
+import org.gradle.api.file.SourceDirectorySet
 import org.gradle.api.plugins.BasePlugin
 import org.gradle.api.tasks.Copy
 import org.gradle.api.tasks.SourceSetContainer
@@ -150,13 +151,13 @@ class JacocoConfig(
         copyReports: TaskProvider<Copy>
     ): TaskProvider<JacocoReport> {
         val allSourceSets = Projects(projects).sourceSets()
-        val mainJavaSrcDirs = allSourceSets.mainJavaSrcDirs()
+        val mainSrcDirs = allSourceSets.mainSrcDirs()
         val humanProducedSourceFolders =
-            FileFilter.producedByHuman(mainJavaSrcDirs)
+            FileFilter.producedByHuman(mainSrcDirs)
 
         val filter = CodebaseFilter(
             rootProject,
-            mainJavaSrcDirs,
+            mainSrcDirs,
             allSourceSets.mainOutputs()
         )
         val humanProducedCompiledFiles = filter.humanProducedCompiledFiles()
@@ -228,12 +229,26 @@ private class SourceSets(
 ) {
 
     /**
-     * Returns all Java source folders corresponding to the `main` source set type.
+     * Returns the union of Java and Kotlin source folders corresponding to the `main`
+     * source set across all underlying [SourceSetContainer]s.
+     *
+     * Kotlin source directories are registered as a separate [SourceDirectorySet]
+     * extension on the source set, not exposed via [allJava][org.gradle.api.tasks.SourceSet.getAllJava].
+     * They are surfaced explicitly here so that generated Kotlin code (for example,
+     * the output of `protoc-gen-kotlin`) is visible to the coverage filter alongside
+     * the Java sources.
      */
-    fun mainJavaSrcDirs(): Set<File> {
+    fun mainSrcDirs(): Set<File> {
         return sourceSets
             .asSequence()
-            .flatMap { it["main"].allJava.srcDirs }
+            .flatMap { container ->
+                val main = container["main"]
+                val javaDirs = main.allJava.srcDirs
+                val kotlinDirs = (main.extensions.findByName("kotlin") as? SourceDirectorySet)
+                    ?.srcDirs
+                    ?: emptySet()
+                javaDirs + kotlinDirs
+            }
             .toSet()
     }
 

buildSrc/src/main/kotlin/io/spine/gradle/report/coverage/PathMarker.kt

@@ -1,5 +1,5 @@
 /*
- * Copyright 2025, TeamDev. All rights reserved.
+ * Copyright 2026, TeamDev. All rights reserved.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -36,26 +36,11 @@ internal enum class PathMarker(val infix: String) {
      */
     GENERATED("generated"),
 
-    /**
-     * Files produced by humans and written in Java.
-     */
-    JAVA_SRC_FOLDER("/java/"),
-
-    /**
-     * Java source files generated by Spine framework.
-     */
-    SPINE_JAVA_SRC_FOLDER("main/spine/"),
-
-    /**
-     * Java source files generated by gRPC plugin.
-     */
-    GRPC_SRC_FOLDER("/main/grpc/"),
-
     /**
      * Among compiler output folders, highlights those containing the compilation result
-     * of human-produced Java files.
+     * for the `main` source set, whether produced by `javac` or `kotlinc`.
      */
-    JAVA_OUTPUT_FOLDER("/main/"),
+    MAIN_OUTPUT_FOLDER("/main/"),
 
     /**
      * Anonymous class.