Mark synthetic methods generated for Java enums as obvious (#2554)

Fixes #2548

3 files changed, 75 insertions, 9 deletions

diff --git a/plugins/base/src/main/kotlin/translators/psi/DefaultPsiToDocumentableTranslator.kt b/plugins/base/src/main/kotlin/translators/psi/DefaultPsiToDocumentableTranslator.kt
index f64eb261..500b0728 100644
--- a/plugins/base/src/main/kotlin/translators/psi/DefaultPsiToDocumentableTranslator.kt
+++ b/plugins/base/src/main/kotlin/translators/psi/DefaultPsiToDocumentableTranslator.kt
@@ -112,9 +112,6 @@ class DefaultPsiToDocumentableTranslator(
         private val PsiClassType.shouldBeIgnored: Boolean
             get() = isClass("java.lang.Enum") || isClass("java.lang.Object")
 
-        private val DRI.isObvious: Boolean
-            get() = packageName == "java.lang" && (classNames == "Object" || classNames == "Enum")
-
         private fun PsiClassType.isClass(qName: String): Boolean {
             val shortName = qName.substringAfterLast('.')
             if (className == shortName) {
@@ -446,7 +443,7 @@ class DefaultPsiToDocumentableTranslator(
                         (psi.annotations.toList()
                             .toListOfAnnotations() + it.toListOfAnnotations()).toSourceSetDependent()
                             .toAnnotations(),
-                        ObviousMember.takeIf { inheritedFrom != null && inheritedFrom.isObvious },
+                        ObviousMember.takeIf { psi.isObvious(inheritedFrom) },
                         psi.throwsList.toDriList().takeIf { it.isNotEmpty() }
                             ?.let { CheckedExceptions(it.toSourceSetDependent()) }
                     )
@@ -454,6 +451,14 @@ class DefaultPsiToDocumentableTranslator(
             )
         }
 
+        private fun PsiMethod.isObvious(inheritedFrom: DRI? = null): Boolean {
+            return this is SyntheticElement || inheritedFrom?.isObvious() == true
+        }
+
+        private fun DRI.isObvious(): Boolean {
+            return packageName == "java.lang" && (classNames == "Object" || classNames == "Enum")
+        }
+
         private fun PsiReferenceList.toDriList() = referenceElements.mapNotNull { it?.resolve()?.let { DRI.from(it) } }
 
         private fun PsiModifierListOwner.additionalExtras() = listOfNotNull(
diff --git a/plugins/base/src/test/kotlin/enums/JavaEnumTest.kt b/plugins/base/src/test/kotlin/enums/JavaEnumTest.kt
new file mode 100644
index 00000000..369fbe79
--- /dev/null
+++ b/plugins/base/src/test/kotlin/enums/JavaEnumTest.kt
@@ -0,0 +1,66 @@
+package enums
+
+import org.jetbrains.dokka.base.testApi.testRunner.BaseAbstractTest
+import org.jetbrains.dokka.model.DEnum
+import org.jetbrains.dokka.model.ObviousMember
+import org.junit.jupiter.api.Test
+import utils.TestOutputWriterPlugin
+import kotlin.test.assertEquals
+import kotlin.test.assertNotNull
+
+class JavaEnumTest : BaseAbstractTest() {
+
+    private val configuration = dokkaConfiguration {
+        sourceSets {
+            sourceSet {
+                sourceRoots = listOf("src/")
+            }
+        }
+    }
+
+    @Test
+    fun `should mark synthetic functions generated for Kotlin as obvious`() {
+        val writerPlugin = TestOutputWriterPlugin()
+        testInline(
+            """
+            |/src/main/java/basic/JavaEnum.java
+            |package testpackage
+            |
+            |public enum JavaEnum {
+            |    ONE, TWO
+            |}
+        """.trimMargin(),
+            configuration,
+            pluginOverrides = listOf(writerPlugin)
+        ) {
+            documentablesCreationStage = { modules ->
+                val pckg = modules.flatMap { it.packages }.single { it.packageName == "testpackage" }
+                val enum = pckg.children.single { it is DEnum } as DEnum
+
+                // there's two with the same name, one inherited from
+                // java.lang.Enum and one is synthetic for Kotlin interop
+                enum.functions.filter { it.name == "valueOf" }.let { valueOfMethods ->
+                    assertEquals(2, valueOfMethods.size)
+
+                    val valueOfFromKotlin = valueOfMethods[0]
+                    assertEquals(
+                        "testpackage/JavaEnum/valueOf/#java.lang.String/PointingToDeclaration/",
+                        valueOfFromKotlin.dri.toString()
+                    )
+                    assertNotNull(valueOfFromKotlin.extra[ObviousMember])
+
+                    val valueOfFromJava = valueOfMethods[1]
+                    assertEquals(
+                        "java.lang/Enum/valueOf/#java.lang.Class<T>#java.lang.String/PointingToDeclaration/",
+                        valueOfFromJava.dri.toString()
+                    )
+                    assertNotNull(valueOfFromJava.extra[ObviousMember])
+                }
+
+                val valuesMethod = enum.functions.single { it.name == "values" }
+                assertEquals("testpackage/JavaEnum/values/#/PointingToDeclaration/", valuesMethod.dri.toString())
+                assertNotNull(valuesMethod.extra[ObviousMember])
+            }
+        }
+    }
+}
diff --git a/plugins/base/src/test/kotlin/model/JavaTest.kt b/plugins/base/src/test/kotlin/model/JavaTest.kt
index 748ef190..0abaf1b1 100644
--- a/plugins/base/src/test/kotlin/model/JavaTest.kt
+++ b/plugins/base/src/test/kotlin/model/JavaTest.kt
@@ -334,11 +334,6 @@ class JavaTest : AbstractModelTest("/src/main/kotlin/java/Test.java", "java") {
             with((this / "java" / "E").cast<DEnum>()) {
                 name equals "E"
                 entries counts 1
-                functions.sortedBy { it.name }.filter { it.name == "valueOf" || it.name == "values" }.map { it.dri } equals listOf(
-                    DRI("java", "E", DRICallable("valueOf", null, listOf(JavaClassReference("java.lang.String"))), PointingToDeclaration),
-                    DRI("java", "E", DRICallable("values", null, emptyList()), PointingToDeclaration),
-                )
-
                 with((this / "Foo").cast<DEnumEntry>()) {
                     name equals "Foo"
                 }