feat: add parsing for language_settings in gapic.yaml (#554)

src/main/java/com/google/api/generator/gapic/model/GapicLanguageSettings.java

@@ -0,0 +1,53 @@
+// 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.model;
+
+import com.google.auto.value.AutoValue;
+import com.google.common.collect.ImmutableMap;
+import java.util.Collections;
+import java.util.Map;
+
+/** Represents the LRO retry settings in a gapic.yaml file. */
+@AutoValue
+public abstract class GapicLanguageSettings {
+  // The Java package mapping.
+  public abstract String pakkage();
+
+  // Private.
+  abstract ImmutableMap<String, String> protoServiceToJavaClass();
+
+  public String getJavaFullName(String protoPackage, String protoRpcName) {
+    String protoFullName = String.format("%s.%s", protoPackage, protoRpcName);
+    String finalProtoRpcName = protoRpcName;
+    if (protoServiceToJavaClass().containsKey(protoFullName)) {
+      finalProtoRpcName = protoServiceToJavaClass().get(protoFullName);
+    }
+    return String.format("%s.%s", pakkage(), finalProtoRpcName);
+  }
+
+  public static Builder builder() {
+    return new AutoValue_GapicLanguageSettings.Builder()
+        .setProtoServiceToJavaClass(Collections.emptyMap());
+  }
+
+  @AutoValue.Builder
+  public abstract static class Builder {
+    public abstract Builder setPakkage(String pakkage);
+
+    public abstract Builder setProtoServiceToJavaClass(Map<String, String> protoServiceToJavaClass);
+
+    public abstract GapicLanguageSettings build();
+  }
+}

src/main/java/com/google/api/generator/gapic/protoparser/GapicLanguageSettingsParser.java

@@ -0,0 +1,92 @@
+// 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.protoparser;
+
+import com.google.api.generator.gapic.model.GapicLanguageSettings;
+import com.google.common.annotations.VisibleForTesting;
+import com.google.common.base.Strings;
+import java.io.File;
+import java.io.IOException;
+import java.nio.file.Files;
+import java.nio.file.Paths;
+import java.util.Map;
+import java.util.Optional;
+import org.yaml.snakeyaml.Yaml;
+import org.yaml.snakeyaml.constructor.SafeConstructor;
+
+public class GapicLanguageSettingsParser {
+  private static final String YAML_KEY_LANGUAGE_SETTINGS = "language_settings";
+  private static final String YAML_KEY_JAVA = "java";
+  private static final String YAML_KEY_PACKAGE_NAME = "package_name";
+  private static final String YAML_KEY_INTERFACE_NAMES = "interface_names";
+
+  public static Optional<GapicLanguageSettings> parse(Optional<String> gapicYamlConfigFilePathOpt) {
+    return gapicYamlConfigFilePathOpt.isPresent()
+        ? parse(gapicYamlConfigFilePathOpt.get())
+        : Optional.empty();
+  }
+
+  @VisibleForTesting
+  static Optional<GapicLanguageSettings> parse(String gapicYamlConfigFilePath) {
+    if (Strings.isNullOrEmpty(gapicYamlConfigFilePath)
+        || !(new File(gapicYamlConfigFilePath)).exists()) {
+      return Optional.empty();
+    }
+
+    String fileContents = null;
+
+    try {
+      fileContents = new String(Files.readAllBytes(Paths.get(gapicYamlConfigFilePath)));
+    } catch (IOException e) {
+      return Optional.empty();
+    }
+
+    Yaml yaml = new Yaml(new SafeConstructor());
+    Map<String, Object> yamlMap = yaml.load(fileContents);
+    return parseFromMap(yamlMap);
+  }
+
+  private static Optional<GapicLanguageSettings> parseFromMap(Map<String, Object> yamlMap) {
+    if (!yamlMap.containsKey(YAML_KEY_LANGUAGE_SETTINGS)) {
+      return Optional.empty();
+    }
+
+    Map<String, Object> languageYamlConfig =
+        (Map<String, Object>) yamlMap.get(YAML_KEY_LANGUAGE_SETTINGS);
+    if (!languageYamlConfig.containsKey(YAML_KEY_JAVA)) {
+      return Optional.empty();
+    }
+
+    Map<String, Object> javaYamlConfig =
+        (Map<String, Object>) languageYamlConfig.get(YAML_KEY_JAVA);
+    if (!javaYamlConfig.containsKey(YAML_KEY_PACKAGE_NAME)) {
+      return Optional.empty();
+    }
+
+    GapicLanguageSettings.Builder gapicLanguageSettingsBuilder =
+        GapicLanguageSettings.builder()
+            .setPakkage((String) javaYamlConfig.get(YAML_KEY_PACKAGE_NAME));
+
+    if (!javaYamlConfig.containsKey(YAML_KEY_INTERFACE_NAMES)) {
+      return Optional.of(gapicLanguageSettingsBuilder.build());
+    }
+
+    return Optional.of(
+        gapicLanguageSettingsBuilder
+            .setProtoServiceToJavaClass(
+                (Map<String, String>) javaYamlConfig.get(YAML_KEY_INTERFACE_NAMES))
+            .build());
+  }
+}

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

@@ -4,6 +4,7 @@ package(default_visibility = ["//visibility:public"])
 
 TESTS = [
     "BatchingSettingsConfigParserTest",
+    "GapicLanguageSettingsParserTest",
     "GapicLroRetrySettingsParserTest",
     "HttpRuleParserTest",
     "MethodSignatureParserTest",

src/test/java/com/google/api/generator/gapic/protoparser/GapicLanguageSettingsParserTest.java

@@ -0,0 +1,57 @@
+// 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.protoparser;
+
+import static junit.framework.Assert.assertEquals;
+import static junit.framework.Assert.assertTrue;
+
+import com.google.api.generator.gapic.model.GapicLanguageSettings;
+import java.nio.file.Path;
+import java.nio.file.Paths;
+import java.util.Optional;
+import org.junit.Test;
+
+public class GapicLanguageSettingsParserTest {
+  private static final String YAML_DIRECTORY =
+      "src/test/java/com/google/api/generator/gapic/testdata/";
+
+  @Test
+  public void parseLanguageSettings_onlyInterfacePresent() {
+    String filename = "datastore_gapic.yaml";
+    Path path = Paths.get(YAML_DIRECTORY, filename);
+    Optional<GapicLanguageSettings> settingsOpt =
+        GapicLanguageSettingsParser.parse(path.toString());
+    assertTrue(settingsOpt.isPresent());
+    GapicLanguageSettings settings = settingsOpt.get();
+    assertEquals("com.google.cloud.datastore.v1", settings.pakkage());
+    assertEquals(
+        "com.google.cloud.datastore.v1.FooBar",
+        settings.getJavaFullName("google.datastore.v1", "FooBar"));
+  }
+
+  @Test
+  public void parseLanguageSettings_methodNameOverridesPresent() {
+    String filename = "logging_gapic.yaml";
+    Path path = Paths.get(YAML_DIRECTORY, filename);
+    Optional<GapicLanguageSettings> settingsOpt =
+        GapicLanguageSettingsParser.parse(path.toString());
+    assertTrue(settingsOpt.isPresent());
+    GapicLanguageSettings settings = settingsOpt.get();
+    assertEquals("com.google.cloud.logging.v2", settings.pakkage());
+    assertEquals(
+        "com.google.cloud.logging.v2.Logging",
+        settings.getJavaFullName("google.logging.v2", "LoggingServiceV2"));
+  }
+}