com.palantir.javaformat.bootstrap.FormatterCommandRunner Maven / Gradle / Ivy
/*
* (c) Copyright 2021 Palantir Technologies Inc. All rights reserved.
*
* 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.palantir.javaformat.bootstrap;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.nio.charset.StandardCharsets;
import java.util.List;
import java.util.Optional;
import java.util.regex.Pattern;
final class FormatterCommandRunner {
private static final Pattern SYNTAX_ERROR_PATTERN = Pattern.compile(":\\d+:\\d+:\\serror:\\s");
static Optional runWithStdin(List command, String input) throws IOException {
Process process = new ProcessBuilder().command(command).start();
try (OutputStream outputStream = process.getOutputStream()) {
outputStream.write(input.getBytes(StandardCharsets.UTF_8));
}
// Make sure to drain stdout before waiting for the process to exit as this can result in a deadlock otherwise.
String stdout = readToString(process.getInputStream());
try {
process.waitFor();
} catch (InterruptedException e) {
throw new RuntimeException("Interrupted while executing command", e);
}
if (process.exitValue() != 0) {
String stderr = readToString(process.getErrorStream());
if (isSyntaxError(stderr)) {
// Don't surface errors due to the formatter failing to parse the java file due to syntax errors.
// In this case, we just want to silently do nothing and not surface an error to e.g. Intellij.
return Optional.empty();
}
throw new IOException(getErrorMessage(command, stdout, stderr));
}
return Optional.of(stdout);
}
/**
* Determine if the command failed due to a syntax error. These errors have the format of:
* ":47:13: error: class, interface, enum, or record expected"
*/
private static boolean isSyntaxError(String stderr) {
return SYNTAX_ERROR_PATTERN.matcher(stderr).find();
}
private static String readToString(InputStream input) throws IOException {
try (input) {
return new String(input.readAllBytes(), StandardCharsets.UTF_8);
}
}
private static String getErrorMessage(List command, String stdout, String stderr) {
return String.join(
"\n",
"Command terminated with exit value 1",
"Command: " + String.join(" ", command),
"Stdout:",
stdout,
"Stderr:",
stderr);
}
}