Hardcode documentation for the synthetic Enum.entries property (#3071)

4 files changed, 116 insertions, 16 deletions

diff --git a/plugins/base/src/main/resources/dokka/docs/kdoc/EnumEntries.kt.template b/plugins/base/src/main/resources/dokka/docs/kdoc/EnumEntries.kt.template
new file mode 100644
index 00000000..20d16421
--- /dev/null
+++ b/plugins/base/src/main/resources/dokka/docs/kdoc/EnumEntries.kt.template
@@ -0,0 +1,3 @@
+Returns a representation of an immutable list of all enum entries, in the order they're declared.
+
+This method may be used to iterate over the enum entries.
diff --git a/plugins/base/src/test/kotlin/translators/DefaultDescriptorToDocumentableTranslatorTest.kt b/plugins/base/src/test/kotlin/translators/DefaultDescriptorToDocumentableTranslatorTest.kt
index c7e2bc21..9a96ad29 100644
--- a/plugins/base/src/test/kotlin/translators/DefaultDescriptorToDocumentableTranslatorTest.kt
+++ b/plugins/base/src/test/kotlin/translators/DefaultDescriptorToDocumentableTranslatorTest.kt
@@ -918,6 +918,69 @@ val soapXml = node("soap-env:Envelope", soapAttrs,
     }
 
     @Test
+    fun `should have documentation for synthetic Enum entries property`() {
+        testInline(
+            """
+            |/src/main/kotlin/test/KotlinEnum.kt
+            |package test
+            |
+            |enum class KotlinEnum {
+            |    FOO, BAR;
+            |}
+            """.trimIndent(),
+            configuration
+        ) {
+            documentablesMergingStage = { module ->
+                val kotlinEnum = module.packages.find { it.name == "test" }
+                    ?.classlikes
+                    ?.single { it.name == "KotlinEnum" }
+
+                checkNotNull(kotlinEnum)
+
+                val entriesProperty = kotlinEnum.properties.single { it.name == "entries" }
+                val expectedEntriesType = GenericTypeConstructor(
+                    dri = DRI(
+                        packageName = "kotlin.enums",
+                        classNames = "EnumEntries"
+                    ),
+                    projections = listOf(
+                        Invariance(
+                            GenericTypeConstructor(
+                                dri = DRI(
+                                    packageName = "test",
+                                    classNames = "KotlinEnum"
+                                ),
+                                projections = emptyList()
+                            )
+                        )
+                    )
+                )
+                assertEquals(expectedEntriesType, entriesProperty.type)
+
+                val expectedDocumentation = DocumentationNode(listOf(
+                    Description(
+                        CustomDocTag(
+                            children = listOf(
+                                P(listOf(
+                                    Text(
+                                        "Returns a representation of an immutable list of all enum entries, " +
+                                                "in the order they're declared."
+                                    ),
+                                )),
+                                P(listOf(
+                                    Text("This method may be used to iterate over the enum entries.")
+                                ))
+                            ),
+                            name = "MARKDOWN_FILE"
+                        )
+                    )
+                ))
+                assertEquals(expectedDocumentation, entriesProperty.documentation.values.single())
+            }
+        }
+    }
+
+    @Test
     fun `should have documentation for synthetic Enum valueOf functions`() {
         testInline(
             """
diff --git a/subprojects/analysis-kotlin-descriptors/compiler/src/main/kotlin/org/jetbrains/dokka/analysis/kotlin/descriptors/compiler/translator/DefaultDescriptorToDocumentableTranslator.kt b/subprojects/analysis-kotlin-descriptors/compiler/src/main/kotlin/org/jetbrains/dokka/analysis/kotlin/descriptors/compiler/translator/DefaultDescriptorToDocumentableTranslator.kt
index 7633a93f..cb52236e 100644
--- a/subprojects/analysis-kotlin-descriptors/compiler/src/main/kotlin/org/jetbrains/dokka/analysis/kotlin/descriptors/compiler/translator/DefaultDescriptorToDocumentableTranslator.kt
+++ b/subprojects/analysis-kotlin-descriptors/compiler/src/main/kotlin/org/jetbrains/dokka/analysis/kotlin/descriptors/compiler/translator/DefaultDescriptorToDocumentableTranslator.kt
@@ -319,11 +319,13 @@ private class DokkaDescriptorVisitor(
         val descriptorsWithKind = this.unsubstitutedMemberScope.getDescriptorsWithKind()
         val staticScopeForKotlinEnum = (this.staticScope as? StaticScopeForKotlinEnum) ?: return descriptorsWithKind
 
-        // synthetic values() and valueOf() functions are not present among average class functions
-        val enumSyntheticFunctions = staticScopeForKotlinEnum.getContributedDescriptors { true }
-            .filterIsInstance<FunctionDescriptor>()
-
-        return descriptorsWithKind.copy(functions = descriptorsWithKind.functions + enumSyntheticFunctions)
+        // synthetic declarations, such as `entries`, `values()` and `valueOf()`,
+        // are not present among real in-code declarationg
+        val contributedDescriptors = staticScopeForKotlinEnum.getContributedDescriptors { true }
+        return descriptorsWithKind.copy(
+            properties = descriptorsWithKind.properties + contributedDescriptors.filterIsInstance<PropertyDescriptor>(),
+            functions = descriptorsWithKind.functions + contributedDescriptors.filterIsInstance<FunctionDescriptor>()
+        )
     }
 
     private suspend fun visitEnumEntryDescriptor(descriptor: ClassDescriptor, parent: DRIWithPlatformInfo): DEnumEntry {
@@ -507,7 +509,7 @@ private class DokkaDescriptorVisitor(
                 getter = getter,
                 setter = setter,
                 visibility = descriptor.getVisibility(implicitAccessors).toSourceSetDependent(),
-                documentation = descriptor.resolveDescriptorData(),
+                documentation = descriptor.getDocumentation(),
                 modifier = descriptor.modifier().toSourceSetDependent(),
                 type = descriptor.returnType!!.toBound(),
                 expectPresentInSet = sourceSet.takeIf { isExpect },
@@ -609,8 +611,8 @@ private class DokkaDescriptorVisitor(
         }
     }
 
-    private fun FunctionDescriptor.getDocumentation(): SourceSetDependent<DocumentationNode> {
-        val isSynthesized = this.kind == CallableMemberDescriptor.Kind.SYNTHESIZED
+    private fun DeclarationDescriptor.getDocumentation(): SourceSetDependent<DocumentationNode> {
+        val isSynthesized = this is CallableMemberDescriptor && this.kind == CallableMemberDescriptor.Kind.SYNTHESIZED
         return if (isSynthesized) {
             syntheticDocProvider.getDocumentation(this)?.toSourceSetDependent() ?: emptyMap()
         } else {
@@ -914,7 +916,7 @@ private class DokkaDescriptorVisitor(
         coroutineScope { parallelMap { visitEnumEntryDescriptor(it, parent) } }
 
     private fun DeclarationDescriptor.resolveDescriptorData(): SourceSetDependent<DocumentationNode> =
-        getDocumentation()?.toSourceSetDependent() ?: emptyMap()
+        resolveDocumentation()?.toSourceSetDependent() ?: emptyMap()
 
 
     private suspend fun toTypeConstructor(kt: KotlinType) =
@@ -1038,7 +1040,7 @@ private class DokkaDescriptorVisitor(
         return effectiveReferencedDescriptors.firstOrNull()?.let { DescriptorToSourceUtils.getSourceFromDescriptor(it) }
     }
 
-    private fun DeclarationDescriptor.getDocumentation(): DocumentationNode? {
+    private fun DeclarationDescriptor.resolveDocumentation(): DocumentationNode? {
         val find = with(kDocFinder) {
             find(::descriptorToAnyDeclaration)
         }
@@ -1050,7 +1052,7 @@ private class DokkaDescriptorVisitor(
                         try {
                             val kdocLink = with(kDocFinder) {
                                 resolveKDocLink(
-                                    fromDescriptor = this@getDocumentation,
+                                    fromDescriptor = this@resolveDocumentation,
                                     qualifiedName = link,
                                     sourceSet = sourceSet
                                 )
diff --git a/subprojects/analysis-kotlin-descriptors/compiler/src/main/kotlin/org/jetbrains/dokka/analysis/kotlin/descriptors/compiler/translator/SyntheticDescriptorDocumentationProvider.kt b/subprojects/analysis-kotlin-descriptors/compiler/src/main/kotlin/org/jetbrains/dokka/analysis/kotlin/descriptors/compiler/translator/SyntheticDescriptorDocumentationProvider.kt
index 3b21f771..b844ddd8 100644
--- a/subprojects/analysis-kotlin-descriptors/compiler/src/main/kotlin/org/jetbrains/dokka/analysis/kotlin/descriptors/compiler/translator/SyntheticDescriptorDocumentationProvider.kt
+++ b/subprojects/analysis-kotlin-descriptors/compiler/src/main/kotlin/org/jetbrains/dokka/analysis/kotlin/descriptors/compiler/translator/SyntheticDescriptorDocumentationProvider.kt
@@ -6,10 +6,15 @@ import org.jetbrains.dokka.analysis.kotlin.descriptors.compiler.configuration.fr
 import org.jetbrains.dokka.analysis.markdown.jb.MarkdownParser
 import org.jetbrains.dokka.links.DRI
 import org.jetbrains.dokka.model.doc.DocumentationNode
+import org.jetbrains.kotlin.builtins.StandardNames
+import org.jetbrains.kotlin.descriptors.CallableMemberDescriptor
 import org.jetbrains.kotlin.descriptors.DeclarationDescriptor
 import org.jetbrains.kotlin.descriptors.FunctionDescriptor
+import org.jetbrains.kotlin.descriptors.PropertyDescriptor
 import org.jetbrains.kotlin.resolve.DescriptorFactory
+import org.jetbrains.kotlin.resolve.DescriptorUtils
 
+private const val ENUM_ENTRIES_TEMPLATE_PATH = "/dokka/docs/kdoc/EnumEntries.kt.template"
 private const val ENUM_VALUEOF_TEMPLATE_PATH = "/dokka/docs/kdoc/EnumValueOf.kt.template"
 private const val ENUM_VALUES_TEMPLATE_PATH = "/dokka/docs/kdoc/EnumValues.kt.template"
 
@@ -17,14 +22,41 @@ internal class SyntheticDescriptorDocumentationProvider(
     private val kDocFinder: KDocFinder,
     private val sourceSet: DokkaConfiguration.DokkaSourceSet
 ) {
-    fun isDocumented(descriptor: DeclarationDescriptor): Boolean = descriptor is FunctionDescriptor
-            && (DescriptorFactory.isEnumValuesMethod(descriptor) || DescriptorFactory.isEnumValueOfMethod(descriptor))
+    fun isDocumented(descriptor: DeclarationDescriptor): Boolean {
+        return when(descriptor) {
+            is PropertyDescriptor -> descriptor.isEnumEntries()
+            is FunctionDescriptor -> {
+                DescriptorFactory.isEnumValuesMethod(descriptor) || DescriptorFactory.isEnumValueOfMethod(descriptor)
+            }
+            else -> false
+        }
+    }
+
+    private fun PropertyDescriptor.isEnumEntries(): Boolean {
+        return this.name == StandardNames.ENUM_ENTRIES
+                && this.kind == CallableMemberDescriptor.Kind.SYNTHESIZED
+                && DescriptorUtils.isEnumClass(this.containingDeclaration)
+    }
 
     fun getDocumentation(descriptor: DeclarationDescriptor): DocumentationNode? {
-        val function = descriptor as? FunctionDescriptor ?: return null
+        return when(descriptor) {
+            is PropertyDescriptor -> descriptor.getDocumentation()
+            is FunctionDescriptor -> descriptor.getDocumentation()
+            else -> null
+        }
+    }
+
+    private fun PropertyDescriptor.getDocumentation(): DocumentationNode? {
+        return when {
+            this.isEnumEntries() -> loadTemplate(this, ENUM_ENTRIES_TEMPLATE_PATH)
+            else -> null
+        }
+    }
+
+    private fun FunctionDescriptor.getDocumentation(): DocumentationNode? {
         return when {
-            DescriptorFactory.isEnumValuesMethod(function) -> loadTemplate(descriptor, ENUM_VALUES_TEMPLATE_PATH)
-            DescriptorFactory.isEnumValueOfMethod(function) -> loadTemplate(descriptor, ENUM_VALUEOF_TEMPLATE_PATH)
+            DescriptorFactory.isEnumValuesMethod(this) -> loadTemplate(this, ENUM_VALUES_TEMPLATE_PATH)
+            DescriptorFactory.isEnumValueOfMethod(this) -> loadTemplate(this, ENUM_VALUEOF_TEMPLATE_PATH)
             else -> null
         }
     }