ContributeSubComponent: Support returning Super Type (#83)

Co-authored-by: Rick Busarow <rickbusarow@gmail.com>

CHANGELOG.md

@@ -3,6 +3,9 @@
 **Unreleased**
 --------------
 
+### Deprecated
+- `ClassReference.functions` has been deprecated in favor of `ClassReference.memberFunctions` and `ClassReference.declaredMemberFunctions`
+
 0.4.0
 -----
 

compiler-utils/api/compiler-utils.api

@@ -300,9 +300,11 @@ public abstract class com/squareup/anvil/compiler/internal/reference/ClassRefere
 	public abstract fun getClassId ()Lorg/jetbrains/kotlin/name/ClassId;
 	public abstract fun getConstructors ()Ljava/util/List;
 	public abstract fun getContainingFileAsJavaFile ()Ljava/io/File;
+	public abstract fun getDeclaredMemberFunctions ()Ljava/util/List;
 	public abstract fun getFqName ()Lorg/jetbrains/kotlin/name/FqName;
 	public abstract fun getFunctions ()Ljava/util/List;
 	protected abstract fun getInnerClassesAndObjects ()Ljava/util/List;
+	public final fun getMemberFunctions ()Ljava/util/List;
 	public abstract fun getModule ()Lcom/squareup/anvil/compiler/internal/reference/AnvilModuleDescriptor;
 	public final fun getPackageFqName ()Lorg/jetbrains/kotlin/name/FqName;
 	public abstract fun getProperties ()Ljava/util/List;
@@ -330,6 +332,7 @@ public final class com/squareup/anvil/compiler/internal/reference/ClassReference
 	public final fun getClazz ()Lorg/jetbrains/kotlin/descriptors/ClassDescriptor;
 	public fun getConstructors ()Ljava/util/List;
 	public fun getContainingFileAsJavaFile ()Ljava/io/File;
+	public fun getDeclaredMemberFunctions ()Ljava/util/List;
 	public fun getFqName ()Lorg/jetbrains/kotlin/name/FqName;
 	public fun getFunctions ()Ljava/util/List;
 	public fun getModule ()Lcom/squareup/anvil/compiler/internal/reference/AnvilModuleDescriptor;
@@ -355,6 +358,7 @@ public final class com/squareup/anvil/compiler/internal/reference/ClassReference
 	public final fun getClazz ()Lorg/jetbrains/kotlin/psi/KtClassOrObject;
 	public fun getConstructors ()Ljava/util/List;
 	public fun getContainingFileAsJavaFile ()Ljava/io/File;
+	public fun getDeclaredMemberFunctions ()Ljava/util/List;
 	public fun getFqName ()Lorg/jetbrains/kotlin/name/FqName;
 	public fun getFunctions ()Ljava/util/List;
 	public fun getModule ()Lcom/squareup/anvil/compiler/internal/reference/AnvilModuleDescriptor;

compiler-utils/src/main/java/com/squareup/anvil/compiler/internal/reference/ClassReference.kt

@@ -66,8 +66,30 @@ public sealed class ClassReference : Comparable<ClassReference>, AnnotatedRefere
   public val packageFqName: FqName get() = classId.packageFqName
 
   public abstract val constructors: List<MemberFunctionReference>
+
+  @Deprecated(
+    "renamed to `declaredMemberFunctions`.  " +
+      "Use `memberFunctions` to include inherited functions.",
+    replaceWith = ReplaceWith("declaredMemberFunctions"),
+  )
   public abstract val functions: List<MemberFunctionReference>
+
+  /**
+   * All functions that are declared in this class, including overrides.
+   * This list does not include inherited functions that are not overridden by this class.
+   */
+  public abstract val declaredMemberFunctions: List<MemberFunctionReference>
+
+  /**
+   * All functions declared in this class or any of its super-types.
+   */
+  public val memberFunctions: List<MemberFunctionReference> by lazy(NONE) {
+    declaredMemberFunctions + directSuperTypeReferences()
+      .flatMap { it.asClassReference().memberFunctions }
+  }
+
   public abstract val properties: List<MemberPropertyReference>
+
   public abstract val typeParameters: List<TypeParameterReference>
 
   protected abstract val innerClassesAndObjects: List<ClassReference>
@@ -146,7 +168,13 @@ public sealed class ClassReference : Comparable<ClassReference>, AnnotatedRefere
       clazz.containingFileAsJavaFile()
     }
 
-    override val functions: List<MemberFunctionReference.Psi> by lazy(NONE) {
+    @Deprecated(
+      "renamed to `declaredMemberFunctions`.  Use `memberFunctions` to include inherited functions.",
+      replaceWith = ReplaceWith("declaredMemberFunctions"),
+    )
+    override val functions: List<MemberFunctionReference.Psi> get() = declaredMemberFunctions
+
+    override val declaredMemberFunctions: List<MemberFunctionReference.Psi> by lazy(NONE) {
       clazz
         .children
         .filterIsInstance<KtClassBody>()
@@ -263,9 +291,14 @@ public sealed class ClassReference : Comparable<ClassReference>, AnnotatedRefere
         )
     }
 
-    override val functions: List<MemberFunctionReference.Descriptor> by lazy(NONE) {
+    @Deprecated(
+      "renamed to `declaredMemberFunctions`.  Use `memberFunctions` to include inherited functions.",
+      replaceWith = ReplaceWith("declaredMemberFunctions"),
+    )
+    override val functions: List<MemberFunctionReference.Descriptor> get() = declaredMemberFunctions
+    override val declaredMemberFunctions: List<MemberFunctionReference.Descriptor> by lazy(NONE) {
       clazz.unsubstitutedMemberScope
-        .getContributedDescriptors(kindFilter = DescriptorKindFilter.FUNCTIONS)
+        .getDescriptorsFiltered(kindFilter = DescriptorKindFilter.FUNCTIONS)
         .filterIsInstance<FunctionDescriptor>()
         .filterNot { it is ConstructorDescriptor }
         .map { it.toFunctionReference(this) }
@@ -279,10 +312,8 @@ public sealed class ClassReference : Comparable<ClassReference>, AnnotatedRefere
       clazz.unsubstitutedMemberScope
         .getDescriptorsFiltered(kindFilter = DescriptorKindFilter.VARIABLES)
         .filterIsInstance<PropertyDescriptor>()
-        .filter {
-          // Remove inherited properties that aren't overridden in this class.
-          it.kind == DECLARATION
-        }
+        // Remove inherited properties that aren't overridden in this class.
+        .filter { it.kind == DECLARATION }
         .map { it.toPropertyReference(this) }
     }
 

compiler/src/main/java/com/squareup/anvil/compiler/codegen/ContributesSubcomponentCodeGen.kt

@@ -207,9 +207,13 @@ internal object ContributesSubcomponentCodeGen : AnvilApplicabilityChecker {
         .filter { it.isAbstract }
         .toList()
 
-      if (functions.size != 1 || functions[0].returnType?.resolve()
-          ?.resolveKSClassDeclaration() != this
-      ) {
+      val returnType = functions.singleOrNull()?.returnType?.resolve()?.resolveKSClassDeclaration()
+      if (returnType != this) {
+
+        val isReturnSuperType = returnType != null && this.superTypes
+          .any { type -> type.resolve().resolveKSClassDeclaration() == returnType }
+        if (isReturnSuperType) return
+
         throw KspAnvilException(
           node = factory,
           message = "A factory must have exactly one abstract function returning the " +
@@ -325,7 +329,7 @@ internal object ContributesSubcomponentCodeGen : AnvilApplicabilityChecker {
         )
       }
 
-      val functions = componentInterface.functions
+      val functions = componentInterface.memberFunctions
         .filter { it.returnType().asClassReference() == this }
 
       if (functions.size >= 2) {
@@ -378,7 +382,7 @@ internal object ContributesSubcomponentCodeGen : AnvilApplicabilityChecker {
         )
       }
 
-      val functions = factory.functions
+      val functions = factory.memberFunctions
         .let { functions ->
           if (factory.isInterface()) {
             functions
@@ -387,7 +391,13 @@ internal object ContributesSubcomponentCodeGen : AnvilApplicabilityChecker {
           }
         }
 
-      if (functions.size != 1 || functions[0].returnType().asClassReference() != this) {
+      val returnType = functions.singleOrNull()?.returnType()?.asClassReference()
+      if (returnType != this) {
+
+        val isReturnSuperType = returnType != null && this.directSuperTypeReferences()
+          .any { it.asClassReference() == returnType }
+        if (isReturnSuperType) return
+
         throw AnvilCompilationExceptionClassReference(
           classReference = factory,
           message = "A factory must have exactly one abstract function returning the " +

compiler/src/main/java/com/squareup/anvil/compiler/codegen/ContributesSubcomponentHandlerGenerator.kt

@@ -294,7 +294,7 @@ internal class ContributesSubcomponentHandlerGenerator(
       )
     }
 
-    val functions = componentInterface.functions
+    val functions = componentInterface.memberFunctions
       .filter { it.isAbstract() && it.visibility() == PUBLIC }
       .filter {
         val returnType = it.returnType().asClassReference()
@@ -333,9 +333,14 @@ internal class ContributesSubcomponentHandlerGenerator(
           )
         }
 
-        val createComponentFunctions = factory.functions
+        val createComponentFunctions = factory.memberFunctions
           .filter { it.isAbstract() }
-          .filter { it.returnType().asClassReference().fqName == contributionFqName }
+          .filter {
+            val returnType = it.returnType().asClassReference()
+            returnType.fqName == contributionFqName ||
+              contribution.clazz.directSuperTypeReferences()
+                .any { type -> type.asClassReference() == returnType }
+          }
 
         if (createComponentFunctions.size != 1) {
           throw AnvilCompilationExceptionClassReference(

compiler/src/main/java/com/squareup/anvil/compiler/codegen/KspContributesSubcomponentHandlerSymbolProcessor.kt

@@ -405,9 +405,14 @@ internal class KspContributesSubcomponentHandlerSymbolProcessor(
               } else {
                 function.asMemberOf(implementingType).returnTypeOrNull()
               }
-            returnTypeToCheck
-              ?.resolveKSClassDeclaration()
-              ?.toClassName() == contributionClassName
+
+            if (returnTypeToCheck != null) {
+              val returnTypeClassName = returnTypeToCheck.resolveKSClassDeclaration()?.toClassName()
+              returnTypeClassName == contributionClassName ||
+                returnTypeToCheck.isAssignableFrom(contribution.clazz.asType(emptyList()))
+            } else {
+              false
+            }
           }
           .toList()
 

compiler/src/main/java/com/squareup/anvil/compiler/codegen/dagger/AssistedFactoryCodeGen.kt

@@ -445,7 +445,7 @@ internal object AssistedFactoryCodeGen : AnvilApplicabilityChecker {
       val assistedFunctions = allSuperTypeClassReferences(includeSelf = true)
         .distinctBy { it.fqName }
         .flatMap { clazz ->
-          clazz.functions
+          clazz.declaredMemberFunctions
             .filter {
               it.isAbstract() &&
                 (it.visibility() == Visibility.PUBLIC || it.visibility() == Visibility.PROTECTED)

compiler/src/main/java/com/squareup/anvil/compiler/codegen/dagger/BindsMethodValidator.kt

@@ -179,7 +179,7 @@ internal object BindsMethodValidator : AnvilApplicabilityChecker {
         .forEach { clazz ->
           (clazz.companionObjects() + clazz)
             .asSequence()
-            .flatMap { it.functions }
+            .flatMap { it.declaredMemberFunctions }
             .filter { it.isAnnotatedWith(daggerBindsFqName) }
             .also { functions ->
               assertNoDuplicateFunctions(clazz, functions)

compiler/src/main/java/com/squareup/anvil/compiler/codegen/dagger/ProvidesMethodFactoryCodeGen.kt

@@ -264,7 +264,7 @@ internal object ProvidesMethodFactoryCodeGen : AnvilApplicabilityChecker {
           .asSequence()
 
         val functions = types
-          .flatMap { it.functions }
+          .flatMap { it.declaredMemberFunctions }
           .filter { it.isAnnotatedWith(daggerProvidesFqName) }
           .onEach { function ->
             checkFunctionIsNotAbstract(clazz, function)

compiler/src/test/java/com/squareup/anvil/compiler/codegen/ContributesSubcomponentGeneratorTest.kt

@@ -110,7 +110,7 @@ class ContributesSubcomponentGeneratorTest(
     }
   }
 
-  @Test fun `there is a hint for contributed subcomponents with an interace factory`() {
+  @Test fun `there is a hint for contributed subcomponents with an interface factory`() {
     compile(
       """
       package com.squareup.test
@@ -493,6 +493,84 @@ class ContributesSubcomponentGeneratorTest(
     }
   }
 
+  @Test fun `a factory function may be defined in a super interface`() {
+    compile(
+      """
+        package com.squareup.test
+        
+        import com.squareup.anvil.annotations.ContributesSubcomponent
+        import com.squareup.anvil.annotations.ContributesSubcomponent.Factory
+        import com.squareup.anvil.annotations.ContributesTo
+        import com.squareup.anvil.annotations.MergeComponent
+        
+        @ContributesSubcomponent(Any::class, parentScope = Unit::class)
+        interface SubcomponentInterface {
+          @ContributesTo(Unit::class)
+          interface AnyParentComponent {
+            fun createFactory(): ComponentFactory
+          }
+      
+          interface Creator {
+            fun createComponent(): SubcomponentInterface
+          }
+      
+          @Factory
+          interface ComponentFactory : Creator
+        }
+        
+        @MergeComponent(Unit::class)
+        interface ComponentInterface
+      """,
+      mode = mode,
+    ) {
+      assertThat(subcomponentInterface.hintSubcomponent?.java).isEqualTo(subcomponentInterface)
+      assertThat(subcomponentInterface.hintSubcomponentParentScope).isEqualTo(Unit::class)
+
+      assertThat(subcomponentInterface.componentFactoryInterface.methods.map { it.name })
+        .containsExactly("createComponent")
+    }
+  }
+
+  @Test fun `a factory function may returns the component super type`() {
+    compile(
+      """
+        package com.squareup.test
+
+        import com.squareup.anvil.annotations.ContributesSubcomponent
+        import com.squareup.anvil.annotations.ContributesSubcomponent.Factory
+        import com.squareup.anvil.annotations.ContributesTo
+        import com.squareup.anvil.annotations.MergeComponent
+
+        interface BaseSubcomponentInterface {
+            interface Factory {
+                fun createComponent(): BaseSubcomponentInterface
+            }
+        }
+
+        @ContributesSubcomponent(Any::class, parentScope = Unit::class)
+        interface SubcomponentInterface : BaseSubcomponentInterface {
+          @Factory
+          interface ComponentFactory: BaseSubcomponentInterface.Factory
+
+          @ContributesTo(Unit::class)
+          interface ParentComponent {
+            fun createFactory(): ComponentFactory
+          }
+        }
+
+        @MergeComponent(Unit::class)
+        interface ComponentInterface
+      """,
+      mode = mode,
+    ) {
+      assertThat(subcomponentInterface.hintSubcomponent?.java).isEqualTo(subcomponentInterface)
+      assertThat(subcomponentInterface.hintSubcomponentParentScope).isEqualTo(Unit::class)
+
+      assertThat(subcomponentInterface.componentFactoryInterface.methods.map { it.name })
+        .containsExactly("createComponent")
+    }
+  }
+
   @Test
   fun `using Dagger's @Subcomponent_Factory is an error`() {
     compile(
@@ -616,6 +694,9 @@ class ContributesSubcomponentGeneratorTest(
   private val Class<*>.parentComponentInterface: Class<*>
     get() = classLoader.loadClass("$canonicalName\$AnyParentComponent")
 
+  private val Class<*>.componentFactoryInterface: Class<*>
+    get() = classLoader.loadClass("$canonicalName\$ComponentFactory")
+
   private val JvmCompilationResult.subcomponentInterface1: Class<*>
     get() = classLoader.loadClass("com.squareup.test.SubcomponentInterface1")
 

compiler/src/test/java/com/squareup/anvil/compiler/internal/reference/ClassReferenceTest.kt

@@ -201,9 +201,13 @@ class ClassReferenceTest {
               assertThat(psiRef.isGenericClass()).isFalse()
               assertThat(descriptorRef.isGenericClass()).isFalse()
 
-              assertThat(psiRef.functions.single().returnType().isGenericType()).isFalse()
               assertThat(
-                descriptorRef.functions.single { it.name == "string" }
+                psiRef.declaredMemberFunctions.single()
+                  .returnType()
+                  .isGenericType(),
+              ).isFalse()
+              assertThat(
+                descriptorRef.declaredMemberFunctions.single { it.name == "string" }
                   .returnType()
                   .isGenericType(),
               ).isFalse()
@@ -223,17 +227,25 @@ class ClassReferenceTest {
               ).isTrue()
             }
             "SomeClass3" -> {
-              assertThat(psiRef.functions.single().returnType().isGenericType()).isTrue()
               assertThat(
-                descriptorRef.functions.single { it.name == "list" }
+                psiRef.declaredMemberFunctions.single()
+                  .returnType()
+                  .isGenericType(),
+              ).isTrue()
+              assertThat(
+                descriptorRef.declaredMemberFunctions.single { it.name == "list" }
                   .returnType()
                   .isGenericType(),
               ).isTrue()
             }
             "SomeClass4" -> {
-              assertThat(psiRef.functions.single().returnType().isGenericType()).isTrue()
               assertThat(
-                descriptorRef.functions.single { it.name == "list" }
+                psiRef.declaredMemberFunctions.single()
+                  .returnType()
+                  .isGenericType(),
+              ).isTrue()
+              assertThat(
+                descriptorRef.declaredMemberFunctions.single { it.name == "list" }
                   .returnType()
                   .isGenericType(),
               ).isTrue()