[ggj] feat: support file header (apache license) for outer class definition

src/main/java/com/google/api/generator/engine/ast/ClassDefinition.java

@@ -23,6 +23,8 @@
 
 @AutoValue
 public abstract class ClassDefinition implements AstNode {
+  // Optional.
+  public abstract ImmutableList<CommentStatement> fileHeader();
   // Required.
   public abstract ScopeNode scope();
   // Required.
@@ -66,6 +68,7 @@ public void accept(AstNodeVisitor visitor) {
 
   public static Builder builder() {
     return new AutoValue_ClassDefinition.Builder()
+        .setFileHeader(Collections.emptyList())
         .setHeaderCommentStatements(Collections.emptyList())
         .setIsNested(false)
         .setIsFinal(false)
@@ -78,8 +81,12 @@ public static Builder builder() {
         .setNestedClasses(Collections.emptyList());
   }
 
+  public abstract Builder toBuilder();
+
   @AutoValue.Builder
   public abstract static class Builder {
+    public abstract Builder setFileHeader(List<CommentStatement> fileHeader);
+
     public abstract Builder setHeaderCommentStatements(
         List<CommentStatement> headerCommentStatements);
 
@@ -129,6 +136,9 @@ public ClassDefinition build() {
         Preconditions.checkState(!classDef.isStatic(), "Outer classes cannot be static");
         Preconditions.checkState(
             !classDef.scope().equals(ScopeNode.PRIVATE), "Outer classes cannot be private");
+      } else {
+        Preconditions.checkState(
+            classDef.fileHeader().isEmpty(), "Nested classes cannot have file header");
       }
 
       // Abstract classes cannot be marked final.

src/main/java/com/google/api/generator/engine/writer/JavaWriterVisitor.java

@@ -679,6 +679,8 @@ public void visit(MethodDefinition methodDefinition) {
   @Override
   public void visit(ClassDefinition classDefinition) {
     if (!classDefinition.isNested()) {
+      statements(classDefinition.fileHeader().stream().collect(Collectors.toList()));
+      newline();
       importWriterVisitor.initialize(
           classDefinition.packageString(), classDefinition.classIdentifier().name());
       buffer.append(String.format("package %s;", classDefinition.packageString()));

src/main/java/com/google/api/generator/gapic/BUILD.bazel

@@ -3,7 +3,7 @@ package(default_visibility = ["//visibility:public"])
 filegroup(
     name = "gapic_files",
     srcs = glob(["*.java"]) + [
-        "//src/test/java/com/google/api/generator/gapic/composer:composer_files",
+        "//src/main/java/com/google/api/generator/gapic/composer:composer_files",
         "//src/main/java/com/google/api/generator/gapic/model:model_files",
         "//src/main/java/com/google/api/generator/gapic/protoparser:protoparser_files",
     ],

src/main/java/com/google/api/generator/gapic/composer/Composer.java

@@ -22,6 +22,8 @@
 import com.google.api.generator.gapic.model.Message;
 import com.google.api.generator.gapic.model.ResourceName;
 import com.google.api.generator.gapic.model.Service;
+import com.google.api.generator.gapic.utils.ApacheLicense;
+import com.google.common.annotations.VisibleForTesting;
 import java.util.ArrayList;
 import java.util.List;
 import java.util.Map;
@@ -36,7 +38,7 @@ public static List<GapicClass> composeServiceClasses(GapicContext context) {
       clazzes.addAll(generateServiceClasses(service, context.messages()));
     }
     clazzes.addAll(generateResourceNameHelperClasses(context.helperResourceNames()));
-    return clazzes;
+    return addApacheLicense(clazzes);
   }
 
   public static List<GapicClass> generateServiceClasses(
@@ -106,4 +108,20 @@ private static GapicClass generateGenericClass(Kind kind, String name, Service s
             .build();
     return GapicClass.create(kind, classDef);
   }
+
+  @VisibleForTesting
+  protected static List<GapicClass> addApacheLicense(List<GapicClass> gapicClassList) {
+    return gapicClassList.stream()
+        .map(
+            gapicClass -> {
+              ClassDefinition classWithHeader =
+                  gapicClass
+                      .classDefinition()
+                      .toBuilder()
+                      .setFileHeader(ApacheLicense.APACHE_LICENSE_COMMENT_STATEMENT)
+                      .build();
+              return GapicClass.create(gapicClass.kind(), classWithHeader);
+            })
+        .collect(Collectors.toList());
+  }
 }

src/main/java/com/google/api/generator/gapic/composer/GrpcServiceStubClassComposer.java

@@ -235,7 +235,8 @@ private static Statement createMethodDescriptorVariableDecl(
     return ExprStatement.withExpr(
         AssignmentExpr.builder()
             .setVariableExpr(
-                methodDescriptorVarExpr.toBuilder()
+                methodDescriptorVarExpr
+                    .toBuilder()
                     .setIsDecl(true)
                     .setScope(ScopeNode.PRIVATE)
                     .setIsStatic(true)
@@ -524,7 +525,9 @@ private static List<MethodDefinition> createConstructorMethods(
     secondCtorExprs.add(
         AssignmentExpr.builder()
             .setVariableExpr(
-                classMemberVarExprs.get("callableFactory").toBuilder()
+                classMemberVarExprs
+                    .get("callableFactory")
+                    .toBuilder()
                     .setExprReferenceExpr(thisExpr)
                     .build())
             .setValueExpr(callableFactoryVarExpr)

src/main/java/com/google/api/generator/gapic/composer/MockServiceImplClassComposer.java

@@ -202,7 +202,8 @@ private static MethodDefinition createSetResponsesMethod(Service service) {
     Expr responseAssignExpr =
         AssignmentExpr.builder()
             .setVariableExpr(
-                responsesVarExpr.toBuilder()
+                responsesVarExpr
+                    .toBuilder()
                     .setExprReferenceExpr(
                         ValueExpr.withValue(ThisObjectValue.withType(getThisClassType(service))))
                     .build())

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

@@ -180,7 +180,9 @@ private static List<Statement> createClassStatements(
     //         "projects/{project}/locations/{location}/autoscalingPolicies/{autoscaling_policy}");
     for (int i = 0; i < patterns.size(); i++) {
       VariableExpr varExpr =
-          templateFinalVarExprs.get(i).toBuilder()
+          templateFinalVarExprs
+              .get(i)
+              .toBuilder()
               .setIsDecl(true)
               .setScope(ScopeNode.PRIVATE)
               .setIsStatic(true)
@@ -202,7 +204,9 @@ private static List<Statement> createClassStatements(
     }
 
     memberVars.add(
-        FIXED_CLASS_VARS.get("fieldValuesMap").toBuilder()
+        FIXED_CLASS_VARS
+            .get("fieldValuesMap")
+            .toBuilder()
             .setIsDecl(true)
             .setScope(ScopeNode.PRIVATE)
             .setIsVolatile(true)
@@ -1244,7 +1248,9 @@ private static ClassDefinition createNestedBuilderClass(
                 .setStaticReferenceType(STATIC_TYPES.get("Objects"))
                 .setMethodName("equals")
                 .setArguments(
-                    FIXED_CLASS_VARS.get("pathTemplate").toBuilder()
+                    FIXED_CLASS_VARS
+                        .get("pathTemplate")
+                        .toBuilder()
                         .setExprReferenceExpr(outerClassVarExpr)
                         .build(),
                     templateFinalVarExpr)
@@ -1272,7 +1278,8 @@ private static ClassDefinition createNestedBuilderClass(
             AssignmentExpr.builder()
                 .setVariableExpr(currClassTokenVarExpr)
                 .setValueExpr(
-                    currClassTokenVarExpr.toBuilder()
+                    currClassTokenVarExpr
+                        .toBuilder()
                         .setExprReferenceExpr(outerClassVarExpr)
                         .build())
                 .build());

src/main/java/com/google/api/generator/gapic/composer/ServiceStubSettingsClassComposer.java

@@ -155,7 +155,8 @@ private static List<Statement> createClassStatements(
 
     // Assign DEFAULT_SERVICE_SCOPES.
     VariableExpr defaultServiceScopesDeclVarExpr =
-        DEFAULT_SERVICE_SCOPES_VAR_EXPR.toBuilder()
+        DEFAULT_SERVICE_SCOPES_VAR_EXPR
+            .toBuilder()
             .setIsDecl(true)
             .setScope(ScopeNode.PRIVATE)
             .setIsStatic(true)

src/main/java/com/google/api/generator/gapic/utils/ApacheLicense.java

@@ -0,0 +1,37 @@
+// Copyright 2020 Google LLC
+//
+// 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.api.generator.gapic.utils;
+
+import com.google.api.generator.engine.ast.BlockComment;
+import com.google.api.generator.engine.ast.CommentStatement;
+import java.util.Arrays;
+import java.util.List;
+
+public class ApacheLicense {
+  private static final String fileHeadeString =
+      "Copyright 2020 Google LLC\n\n"
+          + "Licensed under the Apache License, Version 2.0 (the \"License\");\n"
+          + "you may not use this file except in compliance with the License.\n"
+          + "You may obtain a copy of the License at\n\n"
+          + "     https://www.apache.org/licenses/LICENSE-2.0\n\n"
+          + "Unless required by applicable law or agreed to in writing, software\n"
+          + "distributed under the License is distributed on an \"AS IS\" BASIS,\n"
+          + "WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.\n"
+          + "See the License for the specific language governing permissions and\n"
+          + "limitations under the License.";
+
+  public static final List<CommentStatement> APACHE_LICENSE_COMMENT_STATEMENT =
+      Arrays.asList(CommentStatement.withComment(BlockComment.withComment(fileHeadeString)));
+}

src/main/java/com/google/api/generator/gapic/utils/BUILD.bazel

@@ -11,6 +11,7 @@ java_library(
         ":utils_files",
     ],
     deps = [
+        "//src/main/java/com/google/api/generator/engine/ast",
         "@com_google_guava_guava//jar",
     ],
 )

src/test/java/com/google/api/generator/engine/ast/ClassDefinitionTest.java

@@ -23,7 +23,7 @@
 public class ClassDefinitionTest {
 
   @Test
-  public void validClassDefinition_basicWithComments() {
+  public void validClassDefinition_basicWithCommentsAndHeader() {
     LineComment lineComment = LineComment.withComment("AUTO-GENERATED DOCUMENTATION AND CLASS");
     JavaDocComment javaDocComment =
         JavaDocComment.builder()
@@ -32,6 +32,7 @@ public void validClassDefinition_basicWithComments() {
                 "This class is for advanced usage and reflects the underlying API directly.")
             .build();
     ClassDefinition.builder()
+        .setFileHeader(createFileHeader())
         .setHeaderCommentStatements(
             Arrays.asList(
                 CommentStatement.withComment(lineComment),
@@ -118,6 +119,21 @@ public void validClassDefinition_statementsAndMethods() {
     // No exception thrown, we're good.
   }
 
+  @Test
+  public void invalidClassDefinition_nestedWithFileHeader() {
+    assertThrows(
+        IllegalStateException.class,
+        () -> {
+          ClassDefinition.builder()
+              .setPackageString("com.google.example.library.v1.stub")
+              .setName("LibraryServiceStub")
+              .setIsNested(true)
+              .setScope(ScopeNode.PUBLIC)
+              .setFileHeader(createFileHeader())
+              .build();
+        });
+  }
+
   @Test
   public void invalidClassDefinition_implementsNullType() {
     assertThrows(
@@ -347,4 +363,8 @@ private static ForStatement createForStatement() {
         .setBody(Arrays.asList(ExprStatement.withExpr(createAssignmentExpr())))
         .build();
   }
+  // Create a simple block comment to stand for the Apache License header.
+  private static List<CommentStatement> createFileHeader() {
+    return Arrays.asList(CommentStatement.withComment(BlockComment.withComment("Apache License")));
+  }
 }

src/test/java/com/google/api/generator/engine/writer/JavaWriterVisitorTest.java

@@ -1610,9 +1610,12 @@ public void writeMethodDefinition_templatedReturnTypeAndArguments() {
   }
 
   @Test
-  public void writeClassDefinition_basic() {
+  public void writeClassDefinition_basicWithFileHeader() {
+    List<CommentStatement> fileHeader =
+        Arrays.asList(CommentStatement.withComment(BlockComment.withComment("Apache License")));
     ClassDefinition classDef =
         ClassDefinition.builder()
+            .setFileHeader(fileHeader)
             .setPackageString("com.google.example.library.v1.stub")
             .setName("LibraryServiceStub")
             .setScope(ScopeNode.PUBLIC)
@@ -1622,7 +1625,10 @@ public void writeClassDefinition_basic() {
     assertEquals(
         writerVisitor.write(),
         String.format(
-            createLines(3),
+            createLines(6),
+            "/*\n",
+            " * Apache License\n",
+            " */\n\n",
             "package com.google.example.library.v1.stub;\n",
             "\n",
             "public class LibraryServiceStub {}\n"));

src/test/java/com/google/api/generator/gapic/composer/BUILD.bazel

@@ -1,6 +1,7 @@
 package(default_visibility = ["//visibility:public"])
 
 TESTS = [
+    "ComposerTest",
     "GrpcServiceCallableFactoryClassComposerTest",
     "GrpcServiceStubClassComposerTest",
     "MockServiceClassComposerTest",

src/test/java/com/google/api/generator/gapic/composer/ComposerTest.java

@@ -0,0 +1,62 @@
+// Copyright 2020 Google LLC
+//
+// 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.api.generator.gapic.composer;
+
+import static junit.framework.Assert.assertEquals;
+
+import com.google.api.generator.engine.ast.ClassDefinition;
+import com.google.api.generator.engine.ast.ScopeNode;
+import com.google.api.generator.engine.writer.JavaWriterVisitor;
+import com.google.api.generator.gapic.model.GapicClass;
+import com.google.api.generator.gapic.model.GapicClass.Kind;
+import java.util.Arrays;
+import java.util.List;
+import org.junit.Test;
+
+public class ComposerTest {
+  @Test
+  public void gapicClass_addApacheLicense() {
+    ClassDefinition classDef =
+        ClassDefinition.builder()
+            .setPackageString("com.google.showcase.v1beta1.stub")
+            .setName("EchoStubSettings")
+            .setScope(ScopeNode.PUBLIC)
+            .build();
+    List<GapicClass> gapicClassWithHeaderList =
+        Composer.addApacheLicense(Arrays.asList(GapicClass.create(Kind.TEST, classDef)));
+    JavaWriterVisitor visitor = new JavaWriterVisitor();
+    gapicClassWithHeaderList.get(0).classDefinition().accept(visitor);
+    assertEquals(visitor.write(), EXPECTED_CLASS_STRING);
+  }
+
+  private static final String EXPECTED_CLASS_STRING =
+      "/*\n"
+          + " * Copyright 2020 Google LLC\n"
+          + " *\n"
+          + " * Licensed under the Apache License, Version 2.0 (the \"License\");\n"
+          + " * you may not use this file except in compliance with the License.\n"
+          + " * You may obtain a copy of the License at\n"
+          + " *\n"
+          + " *      https://www.apache.org/licenses/LICENSE-2.0\n"
+          + " *\n"
+          + " * Unless required by applicable law or agreed to in writing, software\n"
+          + " * distributed under the License is distributed on an \"AS IS\" BASIS,\n"
+          + " * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.\n"
+          + " * See the License for the specific language governing permissions and\n"
+          + " * limitations under the License.\n"
+          + " */\n\n"
+          + "package com.google.showcase.v1beta1.stub;\n\n"
+          + "public class EchoStubSettings {}\n";
+}