Integrate Kover (Kotlin#3141)

Author: qwwdfsad

build.gradle

@@ -58,6 +58,7 @@ buildscript {
         classpath "com.moowork.gradle:gradle-node-plugin:$gradle_node_version"
         classpath "org.jetbrains.kotlinx:binary-compatibility-validator:$binary_compatibility_validator_version"
         classpath "ru.vyarus:gradle-animalsniffer-plugin:1.5.3" // Android API check
+        classpath "org.jetbrains.kotlinx:kover:$kover_version"
 
         // JMH plugins
         classpath "com.github.jengelman.gradle.plugins:shadow:5.1.0"
@@ -105,7 +106,8 @@ allprojects {
 }
 
 apply plugin: "binary-compatibility-validator"
-apply plugin: 'base'
+apply plugin: "base"
+apply plugin: "kover-conventions"
 
 apiValidation {
     ignoredProjects += unpublished + ["kotlinx-coroutines-bom"]
@@ -303,7 +305,7 @@ def publishTasks = getTasksByName("publish", true) + getTasksByName("publishNpm"
 
 task deploy(dependsOn: publishTasks)
 
-apply plugin: 'animalsniffer-convention'
+apply plugin: "animalsniffer-conventions"
 
 clean.dependsOn gradle.includedBuilds.collect { it.task(':clean') }
 

buildSrc/build.gradle.kts

@@ -60,4 +60,5 @@ dependencies {
         exclude(group = "org.jetbrains.kotlin", module = "kotlin-stdlib")
     }
     implementation("ru.vyarus:gradle-animalsniffer-plugin:1.5.3") // Android API check
+    implementation("org.jetbrains.kotlinx:kover:${version("kover")}")
 }

buildSrc/src/main/kotlin/animalsniffer-convention.gradle.kts renamed to buildSrc/src/main/kotlin/animalsniffer-conventions.gradle.kts

@@ -0,0 +1,54 @@
+import kotlinx.kover.api.*
+import kotlinx.kover.tasks.*
+
+/*
+ * Copyright 2016-2021 JetBrains s.r.o. Use of this source code is governed by the Apache 2.0 license.
+ */
+apply(plugin = "kover")
+
+val notCovered = sourceless + internal + unpublished
+
+val expectedCoverage = mutableMapOf(
+    // These have lower coverage in general, it can be eventually fixed
+    "kotlinx-coroutines-swing" to 70,
+    "kotlinx-coroutines-android" to 50,
+    "kotlinx-coroutines-javafx" to 39, // JavaFx is not tested on TC because its graphic subsystem cannot be initialized in headless mode
+
+    // TODO figure it out, these probably should be fixed
+    "kotlinx-coroutines-debug" to 84,
+    "kotlinx-coroutines-reactive" to 65,
+    "kotlinx-coroutines-reactor" to 65,
+    "kotlinx-coroutines-rx2" to 78,
+    "kotlinx-coroutines-slf4j" to 81
+)
+
+extensions.configure<KoverExtension> {
+    disabledProjects = notCovered
+    /*
+     * Is explicitly enabled on TC in a separate build step.
+     * Examples:
+     * ./gradlew :p:check -- doesn't verify coverage
+     * ./gradlew :p:check -Pkover.enabled=true -- verifies coverage
+     * ./gradlew :p:koverReport -Pkover.enabled=true -- generates report
+     */
+    isDisabled = !(properties["kover.enabled"]?.toString()?.toBoolean() ?: false)
+}
+
+subprojects {
+    val projectName = name
+    if (projectName in notCovered) return@subprojects
+    tasks.withType<KoverVerificationTask> {
+        rule {
+            bound {
+                /*
+                 * 85 is our baseline that we aim to raise to 90+.
+                 * Missing coverage is typically due to bugs in the agent
+                 * (e.g. signatures deprecated with an error are counted),
+                 * sometimes it's various diagnostic `toString` or `catch` for OOMs/VerificationErrors,
+                 * but some places are definitely worth visiting.
+                 */
+                minValue = expectedCoverage[projectName] ?: 85 // COVERED_LINES_PERCENTAGE
+            }
+        }
+    }
+}

buildSrc/src/main/kotlin/kover-conventions.gradle.kts

@@ -22,7 +22,8 @@ rxjava2_version=2.2.8
 rxjava3_version=3.0.2
 javafx_version=11.0.2
 javafx_plugin_version=0.0.8
-binary_compatibility_validator_version=0.8.0-RC
+binary_compatibility_validator_version=0.8.0
+kover_version=0.5.0-RC2
 blockhound_version=1.0.2.RELEASE
 jna_version=5.9.0
 

gradle.properties

@@ -256,7 +256,7 @@ static void configureJvmForLincheck(task) {
     task.minHeapSize = '1g'
     task.maxHeapSize = '4g' // we may need more space for building an interleaving tree in the model checking mode
     task.jvmArgs = ['--add-opens', 'java.base/jdk.internal.misc=ALL-UNNAMED',   // required for transformation
-                     '--add-exports', 'java.base/jdk.internal.util=ALL-UNNAMED'] // in the model checking mode
+                    '--add-exports', 'java.base/jdk.internal.util=ALL-UNNAMED'] // in the model checking mode
     task.systemProperty 'kotlinx.coroutines.semaphore.segmentSize', '2'
     task.systemProperty 'kotlinx.coroutines.semaphore.maxSpinCycles', '1' // better for the model checking mode
 }
@@ -265,6 +265,28 @@ static void configureJvmForLincheck(task) {
 task moreTest(dependsOn: [jvmStressTest, jvmLincheckTest])
 check.dependsOn moreTest
 
+tasks.jvmLincheckTest {
+    kover {
+        enabled = false // Always disabled, lincheck doesn't really support coverage
+    }
+}
+
+def commonKoverExcludes =
+        ["kotlinx.coroutines.test.*", // Deprecated package for removal
+         "kotlinx.coroutines.debug.*", // Tested by debug module
+         "kotlinx.coroutines.channels.ChannelsKt__DeprecatedKt.*", // Deprecated
+         "kotlinx.coroutines.scheduling.LimitingDispatcher", // Deprecated
+         "kotlinx.coroutines.scheduling.ExperimentalCoroutineDispatcher" // Deprecated
+        ]
+
+tasks.koverHtmlReport {
+    excludes = commonKoverExcludes
+}
+
+tasks.koverVerify {
+    excludes = commonKoverExcludes
+}
+
 task testsJar(type: Jar, dependsOn: jvmTestClasses) {
     classifier = 'tests'
     from compileTestKotlinJvm.destinationDir

kotlinx-coroutines-core/build.gradle

@@ -2,6 +2,8 @@
  * Copyright 2016-2021 JetBrains s.r.o. Use of this source code is governed by the Apache 2.0 license.
  */
 
+import kotlinx.kover.api.*
+
 configurations {
     create("r8")
 }
@@ -103,3 +105,8 @@ open class RunR8 : JavaExec() {
     }
 }
 
+tasks.withType<Test> {
+    extensions.configure<KoverTaskExtension> {
+        excludes = excludes + listOf("com.android.*", "android.*") // Exclude robolectric-generated classes
+    }
+}