Integrate kover

[qwwdfsad]

PTAL.

You can play with it locally, I guess what you will be interested in is :project:koverReport -Pkover.enabled=true.
The link to the report will be in the console output among the last lines.

The overall plan is the following:

• Merge this PR
• Rebase all active branches
• Enable additional TC build step koverVerify -Pkover.enabled=true for Linux builds. JVM-only, separate build step (to avoid unwanted interference with stress and lincheck tests). I will also make HTML reports the part of the build output.
• File an issue and eventually figure out/fix our inconsistent coverage in other projects.

Alternatively, to simplify local development, we could enable Kover unconditionally and explicitly disable in on TC.
I would prefer such an approach in any project but coroutines where we heavily use/rely on stress tests locally.

[dkhalanskyjb]

On Linux, many tests fail for :kotlinx-coroutines-android:test -Pkover.enabled=true. An example:

kotlinx.coroutines.android.HandlerDispatcherTest > testImmediateDispatcherYield FAILED
    java.lang.RuntimeException: java.lang.IllegalAccessException: class org.robolectric.res.ResourceTableFactory cannot access a member of class android.R$styleable with modifiers "private static transient"
        at org.robolectric.res.ResourceTableFactory.addMissingStyleableAttributes(ResourceTableFactory.java:93)
        at org.robolectric.res.ResourceTableFactory.lambda$newFrameworkResourceTable$0(ResourceTableFactory.java:19)
        at org.robolectric.util.PerfStatsCollector.measure(PerfStatsCollector.java:50)
        at org.robolectric.res.ResourceTableFactory.newFrameworkResourceTable(ResourceTableFactory.java:12)
        at org.robolectric.internal.SdkEnvironment.getSystemResourceTable(SdkEnvironment.java:35)
        at org.robolectric.ApkLoader.getSystemResourceTable(ApkLoader.java:32)
        at org.robolectric.android.internal.ParallelUniverse.injectResourceStuffForLegacy(ParallelUniverse.java:266)
        at org.robolectric.android.internal.ParallelUniverse.setUpApplicationState(ParallelUniverse.java:125)
        at org.robolectric.RobolectricTestRunner.beforeTest(RobolectricTestRunner.java:377)
        at org.robolectric.internal.SandboxTestRunner$2.evaluate(SandboxTestRunner.java:252)
        at org.robolectric.internal.SandboxTestRunner.runChild(SandboxTestRunner.java:130)
        at org.robolectric.internal.SandboxTestRunner.runChild(SandboxTestRunner.java:42)
        at org.junit.runners.ParentRunner$3.run(ParentRunner.java:290)
        at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:71)
        at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:288)
        at org.junit.runners.ParentRunner.access$000(ParentRunner.java:58)
        at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:268)
        at org.robolectric.internal.SandboxTestRunner$1.evaluate(SandboxTestRunner.java:84)
        at org.junit.runners.ParentRunner.run(ParentRunner.java:363)
        at org.gradle.api.internal.tasks.testing.junit.JUnitTestClassExecutor.runTestClass(JUnitTestClassExecutor.java:110)
        at org.gradle.api.internal.tasks.testing.junit.JUnitTestClassExecutor.execute(JUnitTestClassExecutor.java:58)
        at org.gradle.api.internal.tasks.testing.junit.JUnitTestClassExecutor.execute(JUnitTestClassExecutor.java:38)
        at org.gradle.api.internal.tasks.testing.junit.AbstractJUnitTestClassProcessor.processTestClass(AbstractJUnitTestClassProcessor.java:62)
        at org.gradle.api.internal.tasks.testing.SuiteTestClassProcessor.processTestClass(SuiteTestClassProcessor.java:51)
        at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
        at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
        at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
        at java.base/java.lang.reflect.Method.invoke(Method.java:566)
        at org.gradle.internal.dispatch.ReflectionDispatch.dispatch(ReflectionDispatch.java:36)
        at org.gradle.internal.dispatch.ReflectionDispatch.dispatch(ReflectionDispatch.java:24)
        at org.gradle.internal.dispatch.ContextClassLoaderDispatch.dispatch(ContextClassLoaderDispatch.java:33)
        at org.gradle.internal.dispatch.ProxyDispatchAdapter$DispatchingInvocationHandler.invoke(ProxyDispatchAdapter.java:94)
        at com.sun.proxy.$Proxy2.processTestClass(Unknown Source)
        at org.gradle.api.internal.tasks.testing.worker.TestWorker.processTestClass(TestWorker.java:119)
        at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
        at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
        at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
        at java.base/java.lang.reflect.Method.invoke(Method.java:566)
        at org.gradle.internal.dispatch.ReflectionDispatch.dispatch(ReflectionDispatch.java:36)
        at org.gradle.internal.dispatch.ReflectionDispatch.dispatch(ReflectionDispatch.java:24)
        at org.gradle.internal.remote.internal.hub.MessageHubBackedObjectConnection$DispatchWrapper.dispatch(MessageHubBackedObjectConnection.java:182)
        at org.gradle.internal.remote.internal.hub.MessageHubBackedObjectConnection$DispatchWrapper.dispatch(MessageHubBackedObjectConnection.java:164)
        at org.gradle.internal.remote.internal.hub.MessageHub$Handler.run(MessageHub.java:414)
        at org.gradle.internal.concurrent.ExecutorPolicy$CatchAndRecordFailures.onExecute(ExecutorPolicy.java:64)
        at org.gradle.internal.concurrent.ManagedExecutorImpl$1.run(ManagedExecutorImpl.java:48)
        at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1128)
        at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:628)
        at org.gradle.internal.concurrent.ThreadFactoryImpl$ManagedThreadRunnable.run(ThreadFactoryImpl.java:56)
        at java.base/java.lang.Thread.run(Thread.java:834)

        Caused by:
        java.lang.IllegalAccessException: class org.robolectric.res.ResourceTableFactory cannot access a member of class android.R$styleable with modifiers "private static transient"
            at java.base/jdk.internal.reflect.Reflection.newIllegalAccessException(Reflection.java:361)
            at java.base/java.lang.reflect.AccessibleObject.checkAccess(AccessibleObject.java:591)
            at java.base/java.lang.reflect.Field.checkAccess(Field.java:1075)
            at java.base/java.lang.reflect.Field.get(Field.java:416)
            at org.robolectric.res.ResourceTableFactory.addMissingStyleableAttributes(ResourceTableFactory.java:91)
            ... 48 more

kotlinx.coroutines.android.HandlerDispatcherTest > testMainDispatcherToString STANDARD_OUT
    [Robolectric] kotlinx.coroutines.android.HandlerDispatcherTest.testMainDispatcherToString: sdk=28; resources=legacy
    [Robolectric] NOTICE: legacy resources mode is deprecated; see http://robolectric.org/migrating/#migrating-to-40

I didn't check the other subprojects. Will post an update once I do.

[qwwdfsad]

My bad, reverted the corresponding exclude at the last moment, the fix (Kotlin/kotlinx-kover#95) is actually applied only when the Android plugin is applied. Fixed