MavenRunner now uses a single ProcessRunner across an entire test class.

Author: nedtwigg

lib/src/main/java/com/diffplug/spotless/ProcessRunner.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2020-2021 DiffPlug
+ * Copyright 2020-2023 DiffPlug
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -16,10 +16,12 @@
 package com.diffplug.spotless;
 
 import java.io.ByteArrayOutputStream;
+import java.io.File;
 import java.io.IOException;
 import java.io.InputStream;
 import java.io.OutputStream;
 import java.nio.charset.Charset;
+import java.nio.charset.StandardCharsets;
 import java.util.Arrays;
 import java.util.List;
 import java.util.concurrent.ExecutionException;
@@ -55,13 +57,18 @@ public Result shell(String cmd) throws IOException, InterruptedException {
 
 	/** Executes the given shell command (using {@code cmd} on windows and {@code sh} on unix). */
 	public Result shellWinUnix(String cmdWin, String cmdUnix) throws IOException, InterruptedException {
+		return shellWinUnix(null, cmdWin, cmdUnix);
+	}
+
+	/** Executes the given shell command (using {@code cmd} on windows and {@code sh} on unix). */
+	public Result shellWinUnix(File cwd, String cmdWin, String cmdUnix) throws IOException, InterruptedException {
 		List<String> args;
 		if (FileSignature.machineIsWin()) {
 			args = Arrays.asList("cmd", "/c", cmdWin);
 		} else {
 			args = Arrays.asList("sh", "-c", cmdUnix);
 		}
-		return exec(args);
+		return exec(cwd, args);
 	}
 
 	/** Creates a process with the given arguments. */
@@ -76,12 +83,25 @@ public Result exec(byte[] stdin, String... args) throws IOException, Interrupted
 
 	/** Creates a process with the given arguments. */
 	public Result exec(List<String> args) throws IOException, InterruptedException {
-		return exec(new byte[0], args);
+		return exec((File) null, args);
+	}
+
+	/** Creates a process with the given arguments. */
+	public Result exec(File cwd, List<String> args) throws IOException, InterruptedException {
+		return exec(cwd, new byte[0], args);
 	}
 
 	/** Creates a process with the given arguments, the given byte array is written to stdin immediately. */
 	public Result exec(byte[] stdin, List<String> args) throws IOException, InterruptedException {
+		return exec(null, stdin, args);
+	}
+
+	/** Creates a process with the given arguments, the given byte array is written to stdin immediately. */
+	public Result exec(File cwd, byte[] stdin, List<String> args) throws IOException, InterruptedException {
 		ProcessBuilder builder = new ProcessBuilder(args);
+		if (cwd != null) {
+			builder.directory(cwd);
+		}
 		Process process = builder.start();
 		Future<byte[]> outputFut = threadStdOut.submit(() -> drainToBytes(process.getInputStream(), bufStdOut));
 		Future<byte[]> errorFut = threadStdErr.submit(() -> drainToBytes(process.getErrorStream(), bufStdErr));
@@ -147,6 +167,14 @@ public byte[] stdErr() {
 			return stdErr;
 		}
 
+		public String stdOutUtf8() {
+			return new String(stdOut, StandardCharsets.UTF_8);
+		}
+
+		public String stdErrUtf8() {
+			return new String(stdErr, StandardCharsets.UTF_8);
+		}
+
 		/** Returns true if the exit code was not zero. */
 		public boolean exitNotZero() {
 			return exitCode != 0;

plugin-maven/src/test/java/com/diffplug/spotless/maven/MavenIntegrationHarness.java

@@ -31,6 +31,8 @@
 import java.nio.file.Path;
 import java.util.*;
 
+import org.junit.jupiter.api.AfterAll;
+import org.junit.jupiter.api.BeforeAll;
 import org.junit.jupiter.api.BeforeEach;
 
 import com.github.mustachejava.DefaultMustacheFactory;
@@ -40,6 +42,7 @@
 import com.diffplug.common.base.Unhandled;
 import com.diffplug.common.io.Resources;
 import com.diffplug.spotless.Jvm;
+import com.diffplug.spotless.ProcessRunner;
 import com.diffplug.spotless.ResourceHarness;
 
 public class MavenIntegrationHarness extends ResourceHarness {
@@ -175,9 +178,22 @@ protected void writePom(String[] executions, String[] configuration, String[] de
 
 	protected MavenRunner mavenRunner() throws IOException {
 		return MavenRunner.create()
+				.withRunner(runner)
 				.withProjectDir(rootFolder());
 	}
 
+	private static ProcessRunner runner;
+
+	@BeforeAll
+	static void setupRunner() throws IOException {
+		runner = new ProcessRunner();
+	}
+
+	@AfterAll
+	static void closeRunner() throws IOException {
+		runner.close();
+	}
+
 	/**
 	 * Useful for local development. Allows debugging the Spotless Maven Plugin remotely.
 	 * Effectively translates into running {@code mvnDebug} on port 5005. The forked JVM will be

plugin-maven/src/test/java/com/diffplug/spotless/maven/MavenRunner.java

@@ -17,21 +17,15 @@
 
 import static org.assertj.core.api.Assertions.assertThat;
 
-import java.io.ByteArrayOutputStream;
 import java.io.File;
 import java.io.IOException;
-import java.io.InputStream;
-import java.nio.charset.Charset;
 import java.util.Arrays;
 import java.util.HashMap;
-import java.util.List;
 import java.util.Map;
 import java.util.Objects;
 
-import com.diffplug.common.base.Throwables;
-import com.diffplug.common.io.ByteStreams;
-import com.diffplug.spotless.FileSignature;
 import com.diffplug.spotless.Jvm;
+import com.diffplug.spotless.ProcessRunner;
 
 /**
  * Harness for running a maven build, same idea as the
@@ -47,6 +41,7 @@ private MavenRunner() {}
 	private File projectDir;
 	private String[] args;
 	private Map<String, String> environment = new HashMap<>();
+	private ProcessRunner runner;
 
 	public MavenRunner withProjectDir(File projectDir) {
 		this.projectDir = Objects.requireNonNull(projectDir);
@@ -58,110 +53,36 @@ public MavenRunner withArguments(String... args) {
 		return this;
 	}
 
+	public MavenRunner withRunner(ProcessRunner runner) {
+		this.runner = runner;
+		return this;
+	}
+
 	public MavenRunner withRemoteDebug(int port) {
 		String address = (Jvm.version() < 9 ? "" : "*:") + port;
 		environment.put("MAVEN_OPTS", "-agentlib:jdwp=transport=dt_socket,server=y,suspend=y,address=" + address);
 		return this;
 	}
 
-	private Result run() throws IOException, InterruptedException {
+	private ProcessRunner.Result run() throws IOException, InterruptedException {
 		Objects.requireNonNull(projectDir, "Need to call withProjectDir() first");
 		Objects.requireNonNull(args, "Need to call withArguments() first");
 		// run maven with the given args in the given directory
-		String argsString = String.join(" ", Arrays.asList(args));
-		List<String> cmds = getPlatformCmds("-e " + argsString);
-		ProcessBuilder builder = new ProcessBuilder(cmds);
-		builder.directory(projectDir);
-		builder.environment().putAll(environment);
-		Process process = builder.start();
-		// slurp and return the stdout, stderr, and exitValue
-		Slurper output = new Slurper(process.getInputStream());
-		Slurper error = new Slurper(process.getErrorStream());
-		int exitValue = process.waitFor();
-		output.join();
-		error.join();
-		return new Result(exitValue, output.result(), error.result());
+		String argsString = "-e " + String.join(" ", Arrays.asList(args));
+		return runner.shellWinUnix(projectDir, "mvnw " + argsString, "./mvnw " + argsString);
 	}
 
 	/** Runs the command and asserts that exit code is 0. */
-	public Result runNoError() throws IOException, InterruptedException {
-		Result result = run();
-		assertThat(result.exitValue()).as("Run without error %s", result).isEqualTo(0);
+	public ProcessRunner.Result runNoError() throws IOException, InterruptedException {
+		ProcessRunner.Result result = run();
+		assertThat(result.exitCode()).as("Run without error %s", result).isEqualTo(0);
 		return result;
 	}
 
 	/** Runs the command and asserts that exit code is not 0. */
-	public Result runHasError() throws IOException, InterruptedException {
-		Result result = run();
-		assertThat(result.exitValue()).as("Run with error %s", result).isNotEqualTo(0);
+	public ProcessRunner.Result runHasError() throws IOException, InterruptedException {
+		ProcessRunner.Result result = run();
+		assertThat(result.exitCode()).as("Run with error %s", result).isNotEqualTo(0);
 		return result;
 	}
-
-	public static class Result {
-		private final int exitValue;
-		private final String output;
-		private final String error;
-
-		public Result(int exitValue, String output, String error) {
-			super();
-			this.exitValue = exitValue;
-			this.output = Objects.requireNonNull(output);
-			this.error = Objects.requireNonNull(error);
-		}
-
-		public int exitValue() {
-			return exitValue;
-		}
-
-		public String output() {
-			return output;
-		}
-
-		public String error() {
-			return error;
-		}
-
-		@Override
-		public String toString() {
-			return "Result{" +
-					"exitValue=" + exitValue +
-					", output='" + output + '\'' +
-					", error='" + error + '\'' +
-					'}';
-		}
-	}
-
-	/** Prepends any arguments necessary to run a console command. */
-	private static List<String> getPlatformCmds(String cmd) {
-		if (FileSignature.machineIsWin()) {
-			return Arrays.asList("cmd", "/c", "mvnw " + cmd);
-		} else {
-			return Arrays.asList("/bin/sh", "-c", "./mvnw " + cmd);
-		}
-	}
-
-	private static class Slurper extends Thread {
-		private final InputStream input;
-		private volatile String result;
-
-		Slurper(InputStream input) {
-			this.input = Objects.requireNonNull(input);
-			start();
-		}
-
-		@Override
-		public void run() {
-			try {
-				ByteArrayOutputStream output = new ByteArrayOutputStream();
-				ByteStreams.copy(input, output);
-				result = output.toString(Charset.defaultCharset().name());
-			} catch (Exception e) {
-				result = Throwables.getStackTraceAsString(e);
-			}
-		}
-
-		public String result() {
-			return result;
-		}
-	}
 }