add gradle tasks for metalava generation

buildSrc/src/main/groovy/com/google/firebase/gradle/plugins/FirebaseLibraryPlugin.java

@@ -15,12 +15,27 @@
 package com.google.firebase.gradle.plugins;
 
 import com.android.build.gradle.LibraryExtension;
+import com.android.build.gradle.api.AndroidSourceSet;
+import com.android.build.gradle.api.LibraryVariant;
 import com.google.common.collect.ImmutableList;
 import com.google.common.collect.ImmutableMap;
+import com.google.firebase.gradle.plugins.apiinfo.GenerateApiTxtFileTask;
+import com.google.firebase.gradle.plugins.apiinfo.ApiInformationTask;
 import com.google.firebase.gradle.plugins.ci.device.FirebaseTestServer;
+
+import java.util.Collection;
+import org.codehaus.groovy.util.ReleaseInfo;
 import org.gradle.api.Plugin;
 import org.gradle.api.Project;
+import org.gradle.api.artifacts.Configuration;
+import org.gradle.api.attributes.Attribute;
+import org.gradle.api.file.FileCollection;
 import org.jetbrains.kotlin.gradle.tasks.KotlinCompile;
+import java.io.File;
+import java.nio.file.Paths;
+import java.util.ArrayList;
+import java.util.List;
+import java.util.stream.Collectors;
 
 public class FirebaseLibraryPlugin implements Plugin<Project> {
 
@@ -54,6 +69,10 @@ public void apply(Project project) {
                 }
               });
     }
+    if (System.getenv().containsKey("METALAVA_BINARY_PATH")) {
+      setupApiInfomrationAnalysis(project, android);
+    }
+
 
     android.testServer(new FirebaseTestServer(project, firebaseLibrary.testLab));
 
@@ -71,6 +90,49 @@ public void apply(Project project) {
                         ImmutableList.of("-module-name", kotlinModuleName(project))));
   }
 
+  private static void setupApiInfomrationAnalysis(Project project, LibraryExtension android) {
+
+    String metalavaBinaryPath = System.getenv("METALAVA_BINARY_PATH");
+    AndroidSourceSet mainSourceSet = android.getSourceSets().getByName("main");
+    File outputFile = project.getRootProject().file(Paths.get(
+        project.getRootProject().getBuildDir().getPath(),
+        "apiinfo",
+        project.getPath().substring(1).replace(":", "_")));
+    File outputApiFile = new File(outputFile.getAbsolutePath() + "_api.txt");
+    String sourcePathArgument = mainSourceSet.getJava().getSrcDirs().stream()
+        .map(File::getAbsolutePath)
+        .collect(Collectors.joining(":"));
+    if(mainSourceSet.getJava().getSrcDirs().stream().noneMatch(File::exists)) {
+      return;
+    }
+
+    project.getTasks().register("apiInformation", ApiInformationTask.class, task -> {
+      task.setApiTxt(project.file("api.txt"));
+      task.setMetalavaBinaryPath(metalavaBinaryPath);
+      task.setSourcePath(sourcePathArgument);
+      task.setOutputFile(outputFile);
+      task.setBaselineFile(project.file("baseline.txt"));
+      task.setOutputApiFile(outputApiFile);
+      if (project.hasProperty("updateBaseline")) {
+        task.setUpdateBaseline(true);
+      } else {
+        task.setUpdateBaseline(false);
+      }
+    });
+
+    project.getTasks().register("generateApiTxtFile", GenerateApiTxtFileTask.class, task -> {
+      task.setApiTxt(project.file("api.txt"));
+      task.setMetalavaBinaryPath(metalavaBinaryPath);
+      task.setSourcePath(sourcePathArgument);
+      task.setBaselineFile(project.file("baseline.txt"));
+      if (project.hasProperty("updateBaseline")) {
+        task.setUpdateBaseline(true);
+      } else {
+        task.setUpdateBaseline(false);
+      }
+    });
+  }
+
   private static void setupStaticAnalysis(
       Project project, LibraryExtension android, FirebaseLibraryExtension library) {
     project.afterEvaluate(

buildSrc/src/main/groovy/com/google/firebase/gradle/plugins/apiinfo/ApiInformationTask.java

@@ -0,0 +1,118 @@
+// Copyright 2019 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.firebase.gradle.plugins.apiinfo;
+
+import java.util.ArrayList;
+import java.util.List;
+import java.util.stream.Collector;
+import java.util.stream.Collectors;
+import java.util.stream.Stream;
+import org.gradle.api.DefaultTask;
+import org.gradle.api.GradleException;
+import org.gradle.api.tasks.Input;
+import org.gradle.api.tasks.InputFile;
+import org.gradle.api.tasks.OutputFile;
+import org.gradle.api.tasks.TaskAction;
+
+import java.io.File;
+import java.io.FileNotFoundException;
+import java.io.FileOutputStream;
+import java.util.Arrays;
+
+/**
+    Task generates the api diff of the current source code against the api.txt file stored
+    alongside the project's src directory.
+ */
+public abstract class ApiInformationTask extends DefaultTask {
+
+    @Input
+    abstract String getMetalavaBinaryPath();
+
+    @InputFile
+    abstract File getApiTxt();
+
+    @Input
+    abstract String getSourcePath();
+
+    @OutputFile
+    abstract File getBaselineFile();
+
+    @OutputFile
+    abstract File getOutputApiFile();
+
+    @Input
+    abstract boolean getUpdateBaseline();
+
+    @OutputFile
+    abstract File getOutputFile();
+
+    public abstract void setSourcePath(String value);
+
+    public abstract void setBaselineFile(File value);
+
+    public abstract void setUpdateBaseline(boolean value);
+
+    public abstract void setMetalavaBinaryPath(String value);
+
+    public abstract void setApiTxt(File value);
+
+    public abstract void setOutputApiFile(File value);
+
+    public abstract void setOutputFile(File value);
+
+
+    @TaskAction
+    void execute() {
+        File outputFileDir = getOutputFile().getParentFile();
+        if(!outputFileDir.exists()) {
+            outputFileDir.mkdirs();
+        }
+
+        // Generate api.txt file and store it in the  build directory.
+        getProject().exec(spec-> {
+            spec.setCommandLine(Arrays.asList(
+                getMetalavaBinaryPath(),
+                "--source-path", getSourcePath(),
+                "--api", getOutputApiFile().getAbsolutePath(),
+                "--format=v2"
+            ));
+            spec.setIgnoreExitValue(true);
+        });
+        getProject().exec(spec-> {
+            List<String> cmd = new ArrayList<>(Arrays.asList(
+                getMetalavaBinaryPath(),
+                "--source-files", getOutputApiFile().getAbsolutePath(),
+                "--check-compatibility:api:current", getApiTxt().getAbsolutePath(),
+                "--format=v2",
+                "--no-color",
+                "--delete-empty-baselines"
+            ));
+            if(getUpdateBaseline()) {
+                cmd.addAll(Arrays.asList("--update-baseline", getBaselineFile().getAbsolutePath()));
+            } else if(getBaselineFile().exists()) {
+                cmd.addAll(Arrays.asList("--baseline", getBaselineFile().getAbsolutePath()));
+            }
+            spec.setCommandLine(cmd);
+            spec.setIgnoreExitValue(true);
+            try {
+                spec.setStandardOutput(new FileOutputStream(getOutputFile()));
+            } catch (FileNotFoundException e) {
+                throw new GradleException("Unable to run the command", e);
+            }
+        });
+
+    }
+
+}

buildSrc/src/main/groovy/com/google/firebase/gradle/plugins/apiinfo/GenerateApiTxtFileTask.java

@@ -0,0 +1,80 @@
+// Copyright 2019 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.firebase.gradle.plugins.apiinfo;
+
+
+import java.util.ArrayList;
+import java.util.List;
+import org.gradle.api.DefaultTask;
+import org.gradle.api.tasks.Input;
+import org.gradle.api.tasks.OutputFile;
+import org.gradle.api.tasks.TaskAction;
+import java.io.File;
+
+import java.util.Arrays;
+
+
+public abstract class GenerateApiTxtFileTask extends DefaultTask {
+
+    @Input
+    abstract String getMetalavaBinaryPath();
+
+    @OutputFile
+    abstract File getApiTxt();
+
+    @Input
+    abstract String getSourcePath();
+
+
+    @OutputFile
+    abstract File getBaselineFile();
+
+    @Input
+    abstract boolean getUpdateBaseline();
+
+
+    public abstract void setSourcePath(String value);
+
+    public abstract void setBaselineFile(File value);
+
+    public abstract void setUpdateBaseline(boolean value);
+
+    public abstract void setMetalavaBinaryPath(String value);
+
+    public abstract void setApiTxt(File value);
+
+    @TaskAction
+    void execute() {
+        List<String> cmd =  new ArrayList<String>(Arrays.asList(
+            getMetalavaBinaryPath(),
+            "--source-path", getSourcePath(),
+            "--api", getApiTxt().getAbsolutePath(),
+            "--format=v2",
+            "--delete-empty-baselines"
+        ));
+
+        if(getUpdateBaseline()) {
+            cmd.addAll(Arrays.asList("--update-baseline", getBaselineFile().getAbsolutePath()));
+        } else if(getBaselineFile().exists()) {
+            cmd.addAll(Arrays.asList("--baseline", getBaselineFile().getAbsolutePath()));
+        }
+
+        getProject().exec(spec -> {
+            spec.setCommandLine(cmd);
+            spec.setIgnoreExitValue(true);
+        });
+
+    }
+}

ci/fireci/fireci/commands.py

@@ -15,6 +15,8 @@
 import click
 import os
 
+from github import Github
+
 from . import gradle
 from . import ci_command
 from . import stats
@@ -61,3 +63,38 @@ def smoke_tests(app_build_variant, test_apps_dir):
             os.path.join(cwd, 'build', 'm2repository')),
         workdir=location,
     )
+
+
+@click.option('--issue_number', 'issue_number', required=True)
+@click.option('--repo_name', 'repo_name', required=True)
+@click.option('--auth_token', 'auth_token', required=True)
+@ci_command()
+def api_information(auth_token, repo_name, issue_number):
+  """Comments the api information on the pr"""
+
+  gradle.run('apiInformation')
+  dir_suffix = 'build/apiinfo'
+  comment_string = ""
+  for filename in os.listdir(dir_suffix):
+    subproject = filename
+    formatted_output_lines = []
+    with open(os.path.join(dir_suffix, filename), 'r') as f:
+      outputlines = f.readlines()
+      for line in outputlines:
+        if 'error' in line:
+          formatted_output_lines.append(line[line.find('error:'):])
+        elif 'warning' in line:
+          formatted_output_lines.append(line[line.find('warning:'):])
+
+    if formatted_output_lines:
+      comment_string += 'The public api surface has changed for the subproject {}:\n'.format(subproject)
+      comment_string += ''.join(formatted_output_lines)
+      comment_string += '\n\n'
+  if comment_string:
+    comment_string += ('Please update the api.txt files for the subprojects being affected by this change '
+      'with the files present in the artifacts directory. Also perform a major/minor bump accordingly.\n')
+    # Comment to github.
+    github_client = Github(auth_token)
+    repo = github_client.get_repo(repo_name)
+    pr = repo.get_pull(int(issue_number))
+    pr.create_issue_comment(comment_string)

ci/fireci/setup.py

@@ -28,6 +28,7 @@
         'click==7.0',
         'opencensus==0.2.0',
         'google-cloud-monitoring==0.31.1',
+        'PyGithub==1.43.8'
     ],
     packages=find_packages(exclude=['tests']),
     entry_points={

firebase-abt/api.txt

@@ -0,0 +1 @@
+// Signature format: 2.0