From 0b2210e8a159975b62b92f794e3898833563aba6 Mon Sep 17 00:00:00 2001
From: Laimonas Turauskas <laimiux@gmail.com>
Date: Thu, 18 Jul 2019 15:00:24 -0700
Subject: [PATCH] Adding module generic support.

---
 integration-tests/upstream/build.gradle       | 18 +++----
 .../reflect/ReflectiveModuleParser.java       | 50 ++++++++++++++++++-
 2 files changed, 57 insertions(+), 11 deletions(-)

diff --git a/integration-tests/upstream/build.gradle b/integration-tests/upstream/build.gradle
index bb7b80bd..cdc7e8ef 100644
--- a/integration-tests/upstream/build.gradle
+++ b/integration-tests/upstream/build.gradle
@@ -43,15 +43,15 @@ test.filter {
   excludeTest 'dagger.functional.BasicTest', null
 
   // TODO reflect bug! Generics don't work well.
-  excludeTest 'dagger.functional.GenericTest', 'complexGenerics'
-  excludeTest 'dagger.functional.GenericTest', 'genericModules'
-  excludeTest 'dagger.functional.GenericTest', 'membersInjections'
-  excludeTest 'dagger.functional.GenericTest', 'noDepsGenerics'
-  excludeTest 'dagger.functional.GenericTest', 'packagePrivateTypeParameterDependencies'
-  excludeTest 'dagger.functional.GenericTest', 'publicSubclassWithPackagePrivateTypeParameterOfSuperclass'
-  excludeTest 'dagger.functional.GenericTest', 'testGenericComponentCreate'
-  excludeTest 'dagger.functional.GenericTest', 'testGenericDoubleReferences'
-  excludeTest 'dagger.functional.GenericTest', 'testGenericSimpleReferences'
+//  excludeTest 'dagger.functional.GenericTest', 'complexGenerics'
+//  excludeTest 'dagger.functional.GenericTest', 'genericModules'
+//  excludeTest 'dagger.functional.GenericTest', 'membersInjections'
+//  excludeTest 'dagger.functional.GenericTest', 'noDepsGenerics'
+//  excludeTest 'dagger.functional.GenericTest', 'packagePrivateTypeParameterDependencies'
+//  excludeTest 'dagger.functional.GenericTest', 'publicSubclassWithPackagePrivateTypeParameterOfSuperclass'
+//  excludeTest 'dagger.functional.GenericTest', 'testGenericComponentCreate'
+//  excludeTest 'dagger.functional.GenericTest', 'testGenericDoubleReferences'
+//  excludeTest 'dagger.functional.GenericTest', 'testGenericSimpleReferences'
   excludeTest 'dagger.functional.binds.BindsTest', 'bindDelegates'
   excludeTest 'dagger.functional.binds.BindsTest', 'bindWithScope'
 
diff --git a/reflect/src/main/java/dagger/reflect/ReflectiveModuleParser.java b/reflect/src/main/java/dagger/reflect/ReflectiveModuleParser.java
index a7fa7d2b..1ec29c54 100644
--- a/reflect/src/main/java/dagger/reflect/ReflectiveModuleParser.java
+++ b/reflect/src/main/java/dagger/reflect/ReflectiveModuleParser.java
@@ -22,7 +22,10 @@
 import java.lang.annotation.Annotation;
 import java.lang.reflect.Method;
 import java.lang.reflect.Modifier;
+import java.lang.reflect.ParameterizedType;
 import java.lang.reflect.Type;
+import java.lang.reflect.TypeVariable;
+import java.util.ArrayList;
 import java.util.Map;
 import java.util.Optional;
 import java.util.Set;
@@ -30,9 +33,11 @@
 
 final class ReflectiveModuleParser {
   static void parse(Class<?> moduleClass, @Nullable Object instance, Scope.Builder scopeBuilder) {
-    for (Class<?> target : Reflection.getDistinctTypeHierarchy(moduleClass)) {
+    Set<Class<?>> hierarchy = Reflection.getDistinctTypeHierarchy(moduleClass);
+    for (Class<?> target : hierarchy) {
       for (Method method : target.getDeclaredMethods()) {
         Type returnType = method.getGenericReturnType();
+
         Annotation[] annotations = method.getAnnotations();
         Annotation qualifier = findQualifier(annotations);
 
@@ -85,7 +90,8 @@ static void parse(Class<?> moduleClass, @Nullable Object instance, Scope.Builder
 
           if (method.getAnnotation(Provides.class) != null) {
             ensureNotPrivate(method);
-            Key key = Key.of(qualifier, returnType);
+
+            Key key = Key.of(qualifier, resolveType(hierarchy, target, returnType));
             Binding binding = new UnlinkedProvidesBinding(instance, method);
             addBinding(scopeBuilder, key, binding, annotations);
           }
@@ -94,6 +100,46 @@ static void parse(Class<?> moduleClass, @Nullable Object instance, Scope.Builder
     }
   }
 
+  private static Type resolveType(Set<Class<?>> moduleClass, Class<?> target, Type type) {
+      if (type instanceof ParameterizedType) {
+        ParameterizedType parameterizedType = (ParameterizedType) type;
+
+        Type[] typeArguments = new Type[parameterizedType.getActualTypeArguments().length];
+
+        int index = 0;
+        for (Type typeArgument : parameterizedType.getActualTypeArguments()) {
+          if (typeArgument instanceof TypeVariable) {
+            for (Class<?> possibility : moduleClass) {
+              if (target != possibility && target.isAssignableFrom(possibility)) {
+                ParameterizedType genericSuperclass = ((ParameterizedType) possibility.getGenericSuperclass());
+                if (genericSuperclass.getRawType() == target) {
+                  int typeIndex = 0;
+                  TypeVariable<? extends Class<?>>[] typeParameters = target.getTypeParameters();
+                  for (int i = 0; i < typeParameters.length; i++) {
+                    if (typeArgument == typeParameters[i]) {
+                      typeIndex = i;
+                    }
+                  }
+
+                  typeArguments[index] = genericSuperclass.getActualTypeArguments()[typeIndex];
+
+                }
+              }
+            }
+          } else {
+            typeArguments[index] = typeArgument;
+          }
+
+
+          index += 1;
+        }
+
+        return new ParameterizedTypeImpl(parameterizedType.getOwnerType(), parameterizedType.getRawType(), typeArguments);
+      }
+
+      return type;
+  }
+
   private static void addBinding(
       Scope.Builder scopeBuilder, Key key, Binding binding, Annotation[] annotations) {
     Annotation scope = findScope(annotations);