Added ability to specify inclusion filter for source sets

Resolves #714
PR #726

Author: shanshin

Diff for: kover-gradle-plugin/api/kover-gradle-plugin.api

@@ -295,6 +295,7 @@ public abstract interface class kotlinx/kover/gradle/plugin/dsl/KoverVariantCrea
 public abstract interface class kotlinx/kover/gradle/plugin/dsl/KoverVariantSources {
 	public abstract fun getExcludeJava ()Lorg/gradle/api/provider/Property;
 	public abstract fun getExcludedSourceSets ()Lorg/gradle/api/provider/SetProperty;
+	public abstract fun getIncludedSourceSets ()Lorg/gradle/api/provider/SetProperty;
 }
 
 public abstract interface class kotlinx/kover/gradle/plugin/dsl/KoverVerificationRulesConfig {

Diff for: kover-gradle-plugin/docs/index.md

@@ -1120,9 +1120,9 @@ By specifying an empty filter `filters { }`, you can completely disable report f
 
 ### Exclusion of JVM source sets
 
-It is possible to exclude from all reports the code declared in certain source sets.
+Code declarations from `test` source set are excluded by default.
 
-As a side effect, the generation of Kover reports ceases to depend on the compilation tasks of these source sets.
+It is possible to exclude from all reports the code declared in certain source sets.
 
 ```kotlin
 kover {
@@ -1134,6 +1134,35 @@ kover {
 }
 ```
 
+In addition, it is possible to exclude classes from all source sets that are not specified.
+
+```kotlin
+kover {
+    currentProject {
+        sources {
+            includedSourceSets.addAll("main")
+        }
+    }
+}
+```
+
+This way, only classes from the `main` source set will be included in the report, but not from others.
+
+These filters can be combined, the `excludedSourceSets` filter has priority.
+```kotlin
+kover {
+    currentProject {
+        sources {
+            includedSourceSets.addAll("main", "extra")
+            excludedSourceSets.addAll("main")
+        }
+    }
+}
+```
+In this case, only classes from the `extra` source set will be included in the report.
+
+As a side effect of the source set exclusion, the generation of Kover reports ceases to depend on the compilation tasks of excluded source sets.
+
 ### Exclusion of test tasks
 If some task does not test the coverage of application classes, 
 or it is necessary to exclude its coverage from reports, then specify this task in the excluded list.

Diff for: kover-gradle-plugin/src/functionalTest/kotlin/kotlinx/kover/gradle/plugin/test/functional/cases/SourceSetsTests.kt

@@ -0,0 +1,131 @@
+/*
+ * Copyright 2017-2025 JetBrains s.r.o. Use of this source code is governed by the Apache 2.0 license.
+ */
+
+package kotlinx.kover.gradle.plugin.test.functional.cases
+
+import kotlinx.kover.gradle.plugin.test.functional.framework.checker.createCheckerContext
+import kotlinx.kover.gradle.plugin.test.functional.framework.runner.buildFromTemplate
+import kotlinx.kover.gradle.plugin.test.functional.framework.runner.runWithParams
+import org.junit.jupiter.api.Test
+import kotlin.test.assertTrue
+
+internal class SourceSetsTests {
+
+    @Test
+    fun testExclude() {
+        val template = buildFromTemplate("sourcesets-multi")
+
+        template.kover {
+            currentProject {
+                sources.excludedSourceSets.addAll("main", "foo")
+            }
+        }
+
+        val gradleBuild = template.generate()
+        val buildResult = gradleBuild.runWithParams(":koverXmlReport")
+
+        gradleBuild.createCheckerContext(buildResult).xmlReport {
+            assertTrue(buildResult.isSuccessful, "Build should be successful")
+            classCounter("kotlinx.kover.examples.sourcesets.MainClass").assertAbsent()
+            classCounter("kotlinx.kover.examples.sourcesets.FooClass").assertAbsent()
+            classCounter("kotlinx.kover.examples.sourcesets.ExtraClass").assertPresent()
+            classCounter("kotlinx.kover.examples.sourcesets.TestClasses").assertAbsent()
+        }
+    }
+
+    @Test
+    fun testInclude() {
+        val template = buildFromTemplate("sourcesets-multi")
+
+        template.kover {
+            currentProject {
+                sources.includedSourceSets.addAll("extra")
+            }
+        }
+
+        val gradleBuild = template.generate()
+        val buildResult = gradleBuild.runWithParams(":koverXmlReport")
+
+        gradleBuild.createCheckerContext(buildResult).xmlReport {
+            assertTrue(buildResult.isSuccessful, "Build should be successful")
+            classCounter("kotlinx.kover.examples.sourcesets.MainClass").assertAbsent()
+            classCounter("kotlinx.kover.examples.sourcesets.FooClass").assertAbsent()
+            classCounter("kotlinx.kover.examples.sourcesets.ExtraClass").assertPresent()
+            classCounter("kotlinx.kover.examples.sourcesets.TestClasses").assertAbsent()
+        }
+    }
+
+    @Test
+    fun testInclude2() {
+        val template = buildFromTemplate("sourcesets-multi")
+
+        template.kover {
+            currentProject {
+                sources.includedSourceSets.addAll("extra", "foo")
+            }
+        }
+
+        val gradleBuild = template.generate()
+        val buildResult = gradleBuild.runWithParams(":koverXmlReport")
+
+        gradleBuild.createCheckerContext(buildResult).xmlReport {
+            assertTrue(buildResult.isSuccessful, "Build should be successful")
+            classCounter("kotlinx.kover.examples.sourcesets.MainClass").assertAbsent()
+            classCounter("kotlinx.kover.examples.sourcesets.FooClass").assertPresent()
+            classCounter("kotlinx.kover.examples.sourcesets.ExtraClass").assertPresent()
+            classCounter("kotlinx.kover.examples.sourcesets.TestClasses").assertAbsent()
+        }
+    }
+
+    @Test
+    fun testMixed() {
+        val template = buildFromTemplate("sourcesets-multi")
+
+        template.kover {
+            currentProject {
+                sources {
+                    includedSourceSets.addAll("extra", "foo")
+                    excludedSourceSets.add("foo")
+                }
+            }
+        }
+
+        val gradleBuild = template.generate()
+        val buildResult = gradleBuild.runWithParams(":koverXmlReport")
+
+        gradleBuild.createCheckerContext(buildResult).xmlReport {
+            assertTrue(buildResult.isSuccessful, "Build should be successful")
+            classCounter("kotlinx.kover.examples.sourcesets.MainClass").assertAbsent()
+            classCounter("kotlinx.kover.examples.sourcesets.FooClass").assertAbsent()
+            classCounter("kotlinx.kover.examples.sourcesets.ExtraClass").assertPresent()
+            classCounter("kotlinx.kover.examples.sourcesets.TestClasses").assertAbsent()
+        }
+    }
+
+    @Test
+    fun testTestSourceSet() {
+        val template = buildFromTemplate("sourcesets-multi")
+
+        template.kover {
+            currentProject {
+                sources {
+                    includedSourceSets.addAll("test")
+                }
+            }
+        }
+
+        val gradleBuild = template.generate()
+        val buildResult = gradleBuild.runWithParams(":koverXmlReport")
+
+        gradleBuild.createCheckerContext(buildResult).xmlReport {
+            assertTrue(buildResult.isSuccessful, "Build should be successful")
+            classCounter("kotlinx.kover.examples.sourcesets.MainClass").assertAbsent()
+            classCounter("kotlinx.kover.examples.sourcesets.FooClass").assertAbsent()
+            classCounter("kotlinx.kover.examples.sourcesets.ExtraClass").assertAbsent()
+            classCounter("kotlinx.kover.examples.sourcesets.TestClasses").assertPresent()
+        }
+    }
+
+
+}

Diff for: kover-gradle-plugin/src/functionalTest/kotlin/kotlinx/kover/gradle/plugin/test/functional/framework/checker/Checker.kt

@@ -460,6 +460,10 @@ private class CounterImpl(
         assertNull(values, "Counter '$symbol' with type '$type' isn't absent")
     }
 
+    override fun assertPresent() {
+        assertNotNull(values, "Counter for '$symbol' with type '$type' isn't present in report")
+    }
+
     override fun assertFullyMissed() {
         assertNotNull(values, "Counter '$symbol' with type '$type' isn't fully missed because it absent")
         assertTrue(values.missed > 0, "Counter '$symbol' with type '$type' isn't fully missed")

Diff for: kover-gradle-plugin/src/functionalTest/kotlin/kotlinx/kover/gradle/plugin/test/functional/framework/checker/CheckerTypes.kt

@@ -73,6 +73,8 @@ internal interface ProjectAnalysisData {
 internal interface Counter {
     fun assertAbsent()
 
+    fun assertPresent()
+
     fun assertFullyMissed()
 
     fun assertCovered()

Diff for: kover-gradle-plugin/src/functionalTest/kotlin/kotlinx/kover/gradle/plugin/test/functional/framework/runner/BuildsRunner.kt

@@ -4,9 +4,14 @@
 
 package kotlinx.kover.gradle.plugin.test.functional.framework.runner
 
+import kotlinx.kover.gradle.plugin.dsl.KoverProjectExtension
+import kotlinx.kover.gradle.plugin.test.functional.framework.common.BuildSlice
+import kotlinx.kover.gradle.plugin.test.functional.framework.common.ScriptLanguage
 import kotlinx.kover.gradle.plugin.test.functional.framework.common.isDebugEnabled
 import kotlinx.kover.gradle.plugin.test.functional.framework.common.logInfo
 import kotlinx.kover.gradle.plugin.test.functional.framework.common.uri
+import kotlinx.kover.gradle.plugin.test.functional.framework.configurator.ProjectScope
+import kotlinx.kover.gradle.plugin.test.functional.framework.mirroring.printGradleDsl
 import kotlinx.kover.gradle.plugin.test.functional.framework.starter.*
 import kotlinx.kover.gradle.plugin.test.functional.framework.starter.buildSrc
 import kotlinx.kover.gradle.plugin.test.functional.framework.starter.patchSettingsFile
@@ -31,6 +36,8 @@ internal interface BuildSource {
 
     fun from(rootProjectDir: File)
 
+    fun kover(config: KoverProjectExtension.(ProjectScope) -> Unit)
+
     fun generate(): GradleBuild
 }
 
@@ -54,6 +61,8 @@ private class BuildSourceImpl(val snapshotRepos: List<String>, val koverVersion:
 
     private var copy: Boolean = false
 
+    private val koverBlocks: MutableList<(ScriptLanguage, String) -> String> = mutableListOf()
+
     override var buildName: String = "default"
 
     override var buildType: String = "default"
@@ -70,6 +79,12 @@ private class BuildSourceImpl(val snapshotRepos: List<String>, val koverVersion:
         copy = false
     }
 
+    override fun kover(config: KoverProjectExtension.(ProjectScope) -> Unit) {
+        koverBlocks += { language, gradle ->
+            printGradleDsl<KoverProjectExtension, ProjectScope>(language, gradle, "kover", config)
+        }
+    }
+
     override fun generate(): GradleBuild {
         val actualDir = dir ?: throw Exception("No source was specified for the build")
         val targetDir = if (copy) {
@@ -88,6 +103,9 @@ private class BuildSourceImpl(val snapshotRepos: List<String>, val koverVersion:
         val buildSrcScript = targetDir.buildSrc?.build
         buildSrcScript?.patchKoverDependency(koverVersion)
 
+        val buildScript = targetDir.build
+        buildScript.addKoverBlocks(koverBlocks)
+
         return GradleBuildImpl(targetDir, copy, buildName, buildType)
     }
 }

Diff for: kover-gradle-plugin/src/functionalTest/kotlin/kotlinx/kover/gradle/plugin/test/functional/framework/starter/Commons.kt

@@ -20,6 +20,7 @@ import java.lang.reflect.Method
 
 private const val DIR_PARAM = "build-directory"
 private const val CHECKER_PARAM = "checker-context"
+private const val GRADLE_WITH_ASSIGN_OPERATOR_VERSION = "8.12"
 
 internal class RunCommand(val buildSource: BuildSource, val gradleArgs: List<String>)
 
@@ -183,3 +184,17 @@ internal fun File.patchKoverDependency(koverVersion: String) {
         }
     }
 }
+
+internal fun File.addKoverBlocks(koverBlocks: MutableList<(ScriptLanguage, String) -> String>) {
+    if (koverBlocks.isEmpty()) return
+
+    val language = if (name.endsWith(".kts")) ScriptLanguage.KTS else ScriptLanguage.GROOVY
+
+    val builder = StringBuilder()
+    koverBlocks.forEach { block ->
+        builder.appendLine()
+        builder.append(block(language, GRADLE_WITH_ASSIGN_OPERATOR_VERSION))
+        builder.appendLine()
+    }
+    appendText(builder.toString())
+}

Diff for: kover-gradle-plugin/src/functionalTest/templates/builds/sourcesets-multi/build.gradle.kts

@@ -0,0 +1,11 @@
+plugins {
+    kotlin("jvm") version "2.1.0"
+    id("org.jetbrains.kotlinx.kover") version "0.7.0"
+}
+
+sourceSets.create("extra")
+sourceSets.create("foo")
+
+dependencies {
+    testImplementation(kotlin("test"))
+}

Diff for: kover-gradle-plugin/src/functionalTest/templates/builds/sourcesets-multi/settings.gradle.kts

@@ -0,0 +1,8 @@
+pluginManagement {
+    repositories {
+        gradlePluginPortal()
+        mavenCentral()
+    }
+}
+rootProject.name = "example-source-multi"
+

Diff for: kover-gradle-plugin/src/functionalTest/templates/builds/sourcesets-multi/src/extra/kotlin/ExtraClass.kt

@@ -0,0 +1,7 @@
+package kotlinx.kover.examples.sourcesets
+
+class ExtraClass {
+    fun function() {
+        println("Example")
+    }
+}

Diff for: kover-gradle-plugin/src/functionalTest/templates/builds/sourcesets-multi/src/foo/kotlin/FooClass.kt

@@ -0,0 +1,7 @@
+package kotlinx.kover.examples.sourcesets
+
+class FooClass {
+    fun function() {
+        println("Example")
+    }
+}

Diff for: kover-gradle-plugin/src/functionalTest/templates/builds/sourcesets-multi/src/main/kotlin/MainClass.kt

@@ -0,0 +1,7 @@
+package kotlinx.kover.examples.sourcesets
+
+class MainClass {
+    fun function() {
+        println("Example")
+    }
+}

Diff for: kover-gradle-plugin/src/functionalTest/templates/builds/sourcesets-multi/src/test/kotlin/TestClasses.kt

@@ -0,0 +1,10 @@
+package kotlinx.kover.examples.sourcesets
+
+import kotlin.test.Test
+
+class TestClasses {
+    @Test
+    fun test() {
+        // no-tests
+    }
+}

Diff for: kover-gradle-plugin/src/main/kotlin/kotlinx/kover/gradle/plugin/appliers/KoverMerge.kt

@@ -97,6 +97,7 @@ private fun KoverVariantSources.wrap(project: Project): KoverMergingVariantSourc
     return object : KoverMergingVariantSources {
         override val excludeJava: Property<Boolean> = this@wrap.excludeJava
         override val excludedSourceSets: SetProperty<String> = this@wrap.excludedSourceSets
+        override val includedSourceSets: SetProperty<String> = this@wrap.includedSourceSets
         override val project: Project = project
     }
 }

Diff for: kover-gradle-plugin/src/main/kotlin/kotlinx/kover/gradle/plugin/appliers/artifacts/JvmVariantArtifacts.kt

@@ -10,6 +10,7 @@ import kotlinx.kover.gradle.plugin.commons.VariantOriginAttr
 import kotlinx.kover.gradle.plugin.dsl.internal.KoverVariantConfigImpl
 import kotlinx.kover.gradle.plugin.appliers.origin.JvmVariantOrigin
 import kotlinx.kover.gradle.plugin.commons.JVM_VARIANT_NAME
+import kotlinx.kover.gradle.plugin.dsl.KoverVariantSources
 import kotlinx.kover.gradle.plugin.dsl.internal.KoverProjectExtensionImpl
 import kotlinx.kover.gradle.plugin.tools.CoverageTool
 import org.gradle.api.Project
@@ -48,9 +49,25 @@ internal class JvmVariantArtifacts(
         }
 
         fromOrigin(variantOrigin) { compilationName ->
-            compilationName !in variantConfig.sources.excludedSourceSets.get()
-                    && compilationName != "test"
+            !compilationIsExcluded(compilationName, variantConfig.sources)
         }
     }
 
+    private fun compilationIsExcluded(compilationName: String, variant: KoverVariantSources): Boolean {
+        if (compilationName in variant.excludedSourceSets.get()) {
+            return true
+        }
+
+        val included = variant.includedSourceSets.get()
+
+        if (included.isEmpty() && compilationName == "test") {
+            return true
+        }
+        if (included.isNotEmpty() && compilationName !in included) {
+            return true
+        }
+
+        return false
+    }
+
 }