diff --git a/core/src/main/java/com/google/googlejavaformat/java/GoogleJavaFormatToolProvider.java b/core/src/main/java/com/google/googlejavaformat/java/GoogleJavaFormatToolProvider.java new file mode 100644 index 000000000..29e028529 --- /dev/null +++ b/core/src/main/java/com/google/googlejavaformat/java/GoogleJavaFormatToolProvider.java @@ -0,0 +1,20 @@ +package com.google.googlejavaformat.java; + +import java.io.PrintWriter; +import java.util.spi.ToolProvider; + +/** Provide a way to be invoked without necessarily starting a new VM. */ +public class GoogleJavaFormatToolProvider implements ToolProvider { + public String name() { + return "google-java-format"; + } + + public int run(PrintWriter out, PrintWriter err, String... args) { + try { + return Main.main(out, err, args); + } catch (Exception e) { + err.print(e.getMessage()); + return -1; // pass non-zero value back indicating an error has happened + } + } +} diff --git a/core/src/main/java/com/google/googlejavaformat/java/Main.java b/core/src/main/java/com/google/googlejavaformat/java/Main.java index 4056f2ae3..953ca5860 100644 --- a/core/src/main/java/com/google/googlejavaformat/java/Main.java +++ b/core/src/main/java/com/google/googlejavaformat/java/Main.java @@ -63,20 +63,27 @@ public Main(PrintWriter outWriter, PrintWriter errWriter, InputStream inStream) * @param args the command-line arguments */ public static void main(String[] args) { - int result; PrintWriter out = new PrintWriter(new OutputStreamWriter(System.out, UTF_8)); PrintWriter err = new PrintWriter(new OutputStreamWriter(System.err, UTF_8)); + int result = main(out, err, args); + System.exit(result); + } + + /** + * Package-private main entry point used this CLI program and the java.util.spi.ToolProvider + * implementation in the same package as this Main class. + */ + static int main(PrintWriter out, PrintWriter err, String... args) { try { Main formatter = new Main(out, err, System.in); - result = formatter.format(args); + return formatter.format(args); } catch (UsageException e) { err.print(e.getMessage()); - result = 0; + return 0; } finally { err.flush(); out.flush(); } - System.exit(result); } /** diff --git a/core/src/main/resources/META-INF/services/java.util.spi.ToolProvider b/core/src/main/resources/META-INF/services/java.util.spi.ToolProvider new file mode 100644 index 000000000..5a90310b0 --- /dev/null +++ b/core/src/main/resources/META-INF/services/java.util.spi.ToolProvider @@ -0,0 +1 @@ +com.google.googlejavaformat.java.GoogleJavaFormatToolProvider diff --git a/core/src/test/java/com/google/googlejavaformat/java/GoogleJavaFormatToolProviderTest.java b/core/src/test/java/com/google/googlejavaformat/java/GoogleJavaFormatToolProviderTest.java new file mode 100644 index 000000000..eb5b50044 --- /dev/null +++ b/core/src/test/java/com/google/googlejavaformat/java/GoogleJavaFormatToolProviderTest.java @@ -0,0 +1,55 @@ +/* + * Copyright 2021 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.googlejavaformat.java; + +import static com.google.common.truth.Truth.assertThat; + +import java.io.PrintWriter; +import java.io.StringWriter; +import java.util.ServiceLoader; +import java.util.spi.ToolProvider; +import org.junit.Test; +import org.junit.runner.RunWith; +import org.junit.runners.JUnit4; + +/** Tests for {@link GoogleJavaFormatToolProvider}. */ +@RunWith(JUnit4.class) +public class GoogleJavaFormatToolProviderTest { + + @Test + public void testUsageOutputAfterLoadingViaToolName() { + String name = "google-java-format"; + + ToolProvider format = + ServiceLoader.load(ToolProvider.class).stream() + .map(ServiceLoader.Provider::get) + .filter(provider -> provider.name().equals(name)) + .findAny() + .orElseThrow(() -> new AssertionError("Tool not found by name: " + name)); + + StringWriter out = new StringWriter(); + StringWriter err = new StringWriter(); + + int result = format.run(new PrintWriter(out, true), new PrintWriter(err, true), "--help"); + + assertThat(result).isEqualTo(0); + + String usage = err.toString(); + + // Check that doc links are included. + assertThat(usage).contains("https://github.com/google/google-java-format"); + assertThat(usage).contains("Usage: google-java-format"); + } +}