Ban @module(subcomponents) from DaggerAdapter until we properly suppo…

…rt it

Supporting it correctly requires a fair amount of thought - Guice and Dagger scopes are different, multibindings are different, and implementing subcomponent factories+builders would be non-trivial. (We could possibly take advantage of child injectors to help?) Anyway, there's more to considered before traversing down this path.

-------------
Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=246354857

extensions/dagger-adapter/src/com/google/inject/daggeradapter/DaggerAdapter.java

@@ -25,6 +25,7 @@
 import com.google.inject.spi.ModuleAnnotatedMethodScanner;
 import java.lang.annotation.Annotation;
 import java.lang.reflect.Method;
+import java.util.Arrays;
 
 /**
  * A utility to adapt classes annotated with {@link @dagger.Module} such that their
@@ -88,7 +89,10 @@ private DaggerCompatibilityModule(ImmutableList<Object> daggerModuleObjects) {
 
     @Override
     public void configure(Binder binder) {
+      binder = binder.skipSources(getClass());
       for (Object module : daggerModuleObjects) {
+        validateNoSubcomponents(binder, module);
+
         binder.install(ProviderMethodsModule.forModule(module, DaggerMethodScanner.INSTANCE));
         checkUnsupportedDaggerAnnotations(module, binder);
       }
@@ -116,6 +120,17 @@ private static Iterable<Method> allDeclaredMethods(Class<?> clazz) {
       return methods.build();
     }
 
+    private void validateNoSubcomponents(Binder binder, Object module) {
+      Class<?> moduleClass = module instanceof Class ? (Class<?>) module : module.getClass();
+      dagger.Module moduleAnnotation = moduleClass.getAnnotation(dagger.Module.class);
+      if (moduleAnnotation.subcomponents().length > 0) {
+        binder.addError(
+            "Subcomponents cannot be configured for modules used with DaggerAdapter. %s specifies:"
+                + " %s",
+            moduleClass, Arrays.toString(moduleAnnotation.subcomponents()));
+      }
+    }
+
     @Override
     public String toString() {
       return MoreObjects.toStringHelper(this).add("modules", daggerModuleObjects).toString();

extensions/dagger-adapter/test/com/google/inject/daggeradapter/ModuleSubcomponentsTest.java

@@ -0,0 +1,53 @@
+/*
+ * Copyright (C) 2019 Google Inc.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package com.google.inject.daggeradapter;
+
+import static com.google.common.truth.Truth.assertThat;
+
+import com.google.inject.CreationException;
+import com.google.inject.Guice;
+import dagger.Module;
+import dagger.Subcomponent;
+import junit.framework.TestCase;
+
+/** Tests for {@code @Module(subcomponents = Foo.class)} */
+
+public class ModuleSubcomponentsTest extends TestCase {
+
+  @Module(subcomponents = TestSubcomponent.class)
+  static class ModuleWithSubcomponents {}
+
+  @Subcomponent
+  interface TestSubcomponent {
+    @Subcomponent.Builder
+    interface Builder {
+      TestSubcomponent build();
+    }
+  }
+
+  public void testModuleSubcomponentsNotSupported() {
+    try {
+      Guice.createInjector(DaggerAdapter.from(ModuleWithSubcomponents.class));
+      fail();
+    } catch (CreationException expected) {
+      assertThat(expected)
+          .hasMessageThat()
+          .contains("Subcomponents cannot be configured for modules used with DaggerAdapter");
+      assertThat(expected).hasMessageThat().contains("ModuleWithSubcomponents specifies: ");
+      assertThat(expected).hasMessageThat().contains("TestSubcomponent");
+    }
+  }
+}