fix: resource name class deduplication

gapic-generator-java/src/main/java/com/google/api/generator/gapic/composer/resourcename/ResourceNameHelperClassComposer.java

@@ -131,7 +131,7 @@ public GapicClass generate(ResourceName resourceName, GapicContext context) {
             .setAnnotations(createClassAnnotations())
             .setScope(ScopeNode.PUBLIC)
             .setName(className)
-            .setImplementsTypes(createImplementsTypes())
+            .setImplementsTypes(createImplementsTypes(className))
             .setStatements(
                 createClassStatements(
                     templateFinalVarExprs,
@@ -160,8 +160,26 @@ private static List<AnnotationNode> createClassAnnotations() {
             .build());
   }
 
-  private static List<TypeNode> createImplementsTypes() {
-    return Arrays.asList(FIXED_TYPESTORE.get("ResourceName"));
+  /**
+   * Builds a list of types to be implemented. If the type has the same name then we use its full
+   * name
+   *
+   * @param implementingClassName class that is implementing the resulting list. Collisions are
+   *     checked
+   * @return
+   */
+  private static List<TypeNode> createImplementsTypes(String implementingClassName) {
+    List<TypeNode> preprocessed = Arrays.asList(FIXED_TYPESTORE.get("ResourceName"));
+    List<TypeNode> result = new ArrayList<>();
+    for (TypeNode typeNode : preprocessed) {
+      if (!typeNode.isPrimitiveType()
+          && typeNode.reference().name().compareTo(implementingClassName) == 0) {
+        result.add(FIXED_TYPESTORE.getWithFullName(typeNode.reference().name()));
+      } else {
+        result.add(typeNode);
+      }
+    }
+    return result;
   }
 
   private static List<VariableExpr> createTemplateClassMembers(

gapic-generator-java/src/main/java/com/google/api/generator/gapic/composer/store/TypeStore.java

@@ -15,16 +15,19 @@
 package com.google.api.generator.gapic.composer.store;
 
 import com.google.api.generator.engine.ast.ConcreteReference;
+import com.google.api.generator.engine.ast.Reference;
 import com.google.api.generator.engine.ast.TypeNode;
 import com.google.api.generator.engine.ast.VaporReference;
 import com.google.api.generator.gapic.model.Message;
+import com.google.common.base.Preconditions;
 import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
 import java.util.stream.Collectors;
 
 public class TypeStore {
   private final Map<String, TypeNode> store = new HashMap<>();
+  private final Map<String, Class<?>> clazzStore = new HashMap<String, Class<?>>();
 
   public TypeStore() {}
 
@@ -33,18 +36,42 @@ public TypeStore(List<Class<?>> concreteClasses) {
   }
 
   private void putConcreteClassses(List<Class<?>> concreteClasses) {
-    store.putAll(
-        concreteClasses.stream()
-            .collect(
-                Collectors.toMap(
-                    Class::getSimpleName,
-                    c -> TypeNode.withReference(ConcreteReference.withClazz(c)))));
+    for (Class<?> clazz : concreteClasses) {
+      store.put(clazz.getSimpleName(), TypeNode.withReference(ConcreteReference.withClazz(clazz)));
+      clazzStore.put(clazz.getSimpleName(), clazz);
+    }
   }
 
   public TypeNode get(String typeName) {
     return store.get(typeName);
   }
 
+  public TypeNode getWithFullName(String typeName) {
+    TypeNode stored = store.get(typeName);
+    Preconditions.checkNotNull(stored);
+    Reference ref;
+    if (stored.reference() instanceof ConcreteReference) {
+      ref =
+          ConcreteReference.builder()
+              .setClazz(clazzStore.get(typeName))
+              .setUseFullName(true)
+              .build();
+    } else if (stored.reference() instanceof VaporReference) {
+      ref =
+          VaporReference.builder()
+              .setUseFullName(true)
+              .setName(typeName)
+              .setPakkage(stored.reference().pakkage())
+              .build();
+    } else {
+      throw new IllegalArgumentException(
+          String.format(
+              "Unexpected reference %s of type %s",
+              typeName, stored.reference().getClass().getSimpleName()));
+    }
+    return TypeNode.withReference(ref);
+  }
+
   public void put(String pakkage, String typeName) {
     store.put(
         typeName,

gapic-generator-java/src/test/java/com/google/api/generator/gapic/composer/resourcename/ResourceNameHelperClassComposerTest.java

@@ -16,6 +16,7 @@
 
 import static com.google.common.truth.Truth.assertThat;
 import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertTrue;
 
 import com.google.api.generator.engine.writer.JavaWriterVisitor;
 import com.google.api.generator.gapic.model.GapicClass;
@@ -34,6 +35,7 @@
 import com.google.protobuf.Descriptors.ServiceDescriptor;
 import com.google.showcase.v1beta1.EchoOuterClass;
 import com.google.showcase.v1beta1.TestingOuterClass;
+import com.google.test.collisions.CollisionsOuterClass;
 import google.cloud.CommonResources;
 import java.nio.file.Path;
 import java.nio.file.Paths;
@@ -50,6 +52,9 @@
 import org.junit.Test;
 
 public class ResourceNameHelperClassComposerTest {
+
+  private final String COLLIDING_RESOURCE_NAME_KEY = "config.googleapis.com/Resource";
+
   private ServiceDescriptor echoService;
   private FileDescriptor echoFileDescriptor;
 
@@ -238,4 +243,29 @@ public void generateResourceNameClass_childSingleton() {
         Paths.get(GoldenFileWriter.getGoldenDir(this.getClass()), "AgentName.golden");
     Assert.assertCodeEquals(goldenFilePath, visitor.write());
   }
+
+  @Test
+  public void generateResourceNameClass_resourceNameCollisionIsAvoided() {
+    ResourceName collidingResourceName =
+        Parser.parseResourceNames(CollisionsOuterClass.getDescriptor())
+            .get(COLLIDING_RESOURCE_NAME_KEY);
+
+    GapicContext irrelevantContext = TestProtoLoader.instance().parseShowcaseEcho();
+    GapicClass clazz =
+        ResourceNameHelperClassComposer.instance()
+            .generate(collidingResourceName, irrelevantContext);
+    JavaWriterVisitor visitor = new JavaWriterVisitor();
+    clazz.classDefinition().accept(visitor);
+    GoldenFileWriter.saveCodegenToFile(
+        this.getClass(), "CollisionResourceName.golden", visitor.write());
+    Path goldenFilePath =
+        Paths.get(GoldenFileWriter.getGoldenDir(this.getClass()), "CollisionResourceName.golden");
+    Assert.assertCodeEquals(goldenFilePath, visitor.write());
+
+    assertEquals(1, clazz.classDefinition().implementsTypes().size());
+    assertTrue(clazz.classDefinition().implementsTypes().get(0).reference().useFullName());
+    assertEquals(
+        clazz.classDefinition().classIdentifier().name(),
+        clazz.classDefinition().implementsTypes().get(0).reference().name());
+  }
 }