Validate list of accepted breaking changes

(cherry picked from commit 79e290a)

Author: marcphilipp

gradle/plugins/japicmp/src/main/kotlin/junitbuild.japicmp.gradle.kts

@@ -1,10 +1,13 @@
 import de.undercouch.gradle.tasks.download.Download
 import junitbuild.extensions.javaModuleName
+import junitbuild.japicmp.AcceptedViolationSuppressor
+import junitbuild.japicmp.AcceptedViolationsPostProcessRule
+import junitbuild.japicmp.BreakingSuperClassChangeRule
 import junitbuild.japicmp.InternalApiFilter
 import junitbuild.japicmp.JApiCmpExtension
-import junitbuild.japicmp.UnacceptedIncompatibilityRule
-import junitbuild.japicmp.UnacceptedSuperClassChangeRule
+import junitbuild.japicmp.SourceIncompatibleRule
 import me.champeau.gradle.japicmp.JapicmpTask
+import me.champeau.gradle.japicmp.report.stdrules.BinaryIncompatibleRule
 import me.champeau.gradle.japicmp.report.stdrules.RecordSeenMembersSetup
 
 plugins {
@@ -19,7 +22,7 @@ val extension = extensions.create<JApiCmpExtension>("japicmp").apply {
 		val acceptedBreakingChangesFile = rootProject.layout.projectDirectory.file("gradle/config/japicmp/accepted-breaking-changes.txt")
 		if (acceptedBreakingChangesFile.asFile.exists()) {
 			convention(providers.fileContents(acceptedBreakingChangesFile).asText
-				.map { it.lineSequence().filter { it.startsWith(project.javaModuleName) }.toList() })
+				.map { it.lineSequence().filter { line -> line.startsWith(project.javaModuleName) }.toList() })
 		} else {
 			empty()
 		}
@@ -50,15 +53,18 @@ val checkBackwardCompatibility by tasks.registering(JapicmpTask::class) {
 	newClasspath.from(tasks.jar)
 	onlyModified = true
 	ignoreMissingClasses = true
-	txtOutputFile = layout.buildDirectory.file("reports/japicmp/plain-report.txt")
-	mdOutputFile = layout.buildDirectory.file("reports/japicmp/plain-report.md")
 	htmlOutputFile = layout.buildDirectory.file("reports/japicmp/plain-report.html")
 	addExcludeFilter(InternalApiFilter::class.java)
 	packageExcludes.add("*.shadow.*")
 	inputs.property("acceptedIncompatibilities", extension.acceptedIncompatibilities)
 	richReport {
+		title = "Compatibility report"
+		description = extension.previousVersion.map { "and source compatibility compared against $it" }
 		destinationDir = layout.buildDirectory.dir("reports/japicmp")
 		addSetupRule(RecordSeenMembersSetup::class.java)
+		addRule(BreakingSuperClassChangeRule::class.java)
+		addRule(BinaryIncompatibleRule::class.java)
+		addRule(SourceIncompatibleRule::class.java)
 	}
 }
 
@@ -72,8 +78,8 @@ afterEvaluate {
 	)
 	checkBackwardCompatibility {
 		richReport {
-			addRule(UnacceptedIncompatibilityRule::class.java, params)
-			addRule(UnacceptedSuperClassChangeRule::class.java, params)
+			addViolationTransformer(AcceptedViolationSuppressor::class.java, params)
+			addPostProcessRule(AcceptedViolationsPostProcessRule::class.java, params)
 		}
 	}
 }

gradle/plugins/japicmp/src/main/kotlin/junitbuild/japicmp/AcceptedViolationSuppressor.kt

@@ -0,0 +1,30 @@
+package junitbuild.japicmp
+
+import japicmp.model.JApiClass
+import japicmp.model.JApiImplementedInterface
+import me.champeau.gradle.japicmp.report.Severity.accepted
+import me.champeau.gradle.japicmp.report.Violation
+import me.champeau.gradle.japicmp.report.ViolationTransformer
+import java.util.*
+
+class AcceptedViolationSuppressor(params: Map<String, String>) : ViolationTransformer {
+
+    val acceptedIncompatibilities = params["acceptedIncompatibilities"]!!.split(',').filter { !it.isEmpty() }.toSet()
+
+    override fun transform(type: String?, violation: Violation): Optional<Violation> = when {
+        violation.isRedundant() -> Optional.empty()
+        violation.isAccepted() -> Optional.of(violation.withSeverity(accepted))
+        else -> Optional.of(violation)
+    }
+
+    private fun Violation.isRedundant(): Boolean =
+        // The changes about the interface's methods will be reported already
+        member is JApiImplementedInterface
+                // A member of the class breaks binary or source compatibility and will be reported
+                || (member is JApiClass && member.compatibilityChanges.none { !it.isBinaryCompatible || !it.isSourceCompatible } && !member.isBreakingSuperClassChange())
+
+    private fun Violation.isAccepted(): Boolean =
+        acceptedIncompatibilities.contains(member.fullyQualifiedName)
+                || acceptedIncompatibilities.contains(member.fullyQualifiedClassName)
+
+}

gradle/plugins/japicmp/src/main/kotlin/junitbuild/japicmp/AcceptedViolationsPostProcessRule.kt

@@ -0,0 +1,32 @@
+package junitbuild.japicmp
+
+import me.champeau.gradle.japicmp.report.PostProcessViolationsRule
+import me.champeau.gradle.japicmp.report.Severity.accepted
+import me.champeau.gradle.japicmp.report.ViolationCheckContextWithViolations
+
+class AcceptedViolationsPostProcessRule(params: Map<String, String>) : PostProcessViolationsRule {
+
+    val acceptedViolations = params["acceptedIncompatibilities"]!!.split(',').filter { !it.isEmpty() }.toSet()
+
+    override fun execute(context: ViolationCheckContextWithViolations) {
+
+        val actualViolations = context.violations.asSequence()
+            .flatMap { it.value.asSequence() }
+            .filter { it.severity == accepted }
+            .map { it.member }
+            .flatMap {
+                sequenceOf(
+                    it.fullyQualifiedClassName,
+                    it.fullyQualifiedName
+                )
+            }
+            .toSet()
+
+        val diff = acceptedViolations - actualViolations
+
+        require(diff.isEmpty()) {
+            "The following elements are listed as 'accepted' but are not actually violations:\n- ${diff.joinToString("\n- ")}"
+        }
+    }
+
+}

gradle/plugins/japicmp/src/main/kotlin/junitbuild/japicmp/BreakingSuperClassChangeRule.kt

@@ -0,0 +1,16 @@
+package junitbuild.japicmp
+
+import japicmp.model.JApiCompatibility
+import me.champeau.gradle.japicmp.report.Violation
+import me.champeau.gradle.japicmp.report.stdrules.AbstractRecordingSeenMembers
+
+// Required due to https://github.com/melix/japicmp-gradle-plugin/issues/56
+class BreakingSuperClassChangeRule : AbstractRecordingSeenMembers() {
+
+    override fun maybeAddViolation(element: JApiCompatibility): Violation? {
+        return when {
+            element.isBreakingSuperClassChange() -> Violation.error(element, "Is not binary compatible due to super class change")
+            else -> null
+        }
+    }
+}

gradle/plugins/japicmp/src/main/kotlin/junitbuild/japicmp/JApiCompatibilityExtensions.kt

@@ -0,0 +1,31 @@
+package junitbuild.japicmp
+
+import japicmp.model.JApiBehavior
+import japicmp.model.JApiClass
+import japicmp.model.JApiCompatibility
+import japicmp.model.JApiField
+
+internal val JApiCompatibility.fullyQualifiedName: String
+    get() = when (this) {
+        is JApiClass -> fullyQualifiedClassName
+        is JApiBehavior -> "${fullyQualifiedClassName}#${name}"
+        is JApiField -> "${fullyQualifiedClassName}#${name}"
+        else -> throw IllegalArgumentException("Could not determine fully-qualified name for $this")
+    }
+
+internal val JApiCompatibility.fullyQualifiedClassName: String
+    get() = when (this) {
+        is JApiClass -> fullyQualifiedName
+        is JApiBehavior -> getjApiClass().fullyQualifiedName
+        is JApiField -> getjApiClass().fullyQualifiedName
+        else -> throw IllegalArgumentException("Could not determine fully-qualified class name for $this")
+    }
+
+internal fun JApiCompatibility.isBreakingSuperClassChange(): Boolean {
+    if (this !is JApiClass || superclass.isBinaryCompatible || superclass.compatibilityChanges.isEmpty()) {
+        return false
+    }
+    // breaking change would otherwise be reported
+    return oldClass.isPresent && newClass.isPresent
+
+}

gradle/plugins/japicmp/src/main/kotlin/junitbuild/japicmp/SeveritySource.kt

@@ -0,0 +1,13 @@
+package junitbuild.japicmp
+
+import japicmp.model.JApiCompatibility
+import me.champeau.gradle.japicmp.report.Violation
+import me.champeau.gradle.japicmp.report.stdrules.AbstractRecordingSeenMembers
+
+class SourceIncompatibleRule : AbstractRecordingSeenMembers() {
+
+    override fun maybeAddViolation(member: JApiCompatibility): Violation? = when {
+        !member.isSourceCompatible -> Violation.error(member, "Is not source compatible")
+        else -> null
+    }
+}

gradle/plugins/japicmp/src/main/kotlin/junitbuild/japicmp/SourceIncompatibleRule.kt

@@ -12,3 +12,7 @@ dependencies {
 	osgiVerification(projects.junitJupiterEngine)
 	osgiVerification(projects.junitPlatformLauncher)
 }
+
+japicmp {
+	acceptedIncompatibilities.empty()
+}