🏗🚀 Significantly speed up gulp prettify

build-system/tasks/prettify.js

@@ -24,26 +24,22 @@
 
 const argv = require('minimist')(process.argv.slice(2));
 const globby = require('globby');
+const gulp = require('gulp');
 const log = require('fancy-log');
+const path = require('path');
+const prettier = require('gulp-prettier');
 const {getFilesChanged, logOnSameLine} = require('../common/utils');
-const {getOutput} = require('../common/exec');
 const {green, cyan, red, yellow} = require('ansi-colors');
-const {highlight} = require('cli-highlight');
 const {isTravisBuild} = require('../common/travis');
 const {maybeUpdatePackages} = require('./update-packages');
 const {prettifyGlobs} = require('../test-configs/config');
 
-const prettierCmd = 'node_modules/.bin/prettier';
+const rootDir = path.dirname(path.dirname(__dirname));
 
-/**
- * Prettier exit codes. See https://prettier.io/docs/en/cli.html#exit-codes
- * @enum {number}
- */
-const PrettierResult = {
-  SUCCESS: 0,
-  FAILURE: 1,
-  ERROR: 2,
-};
+// Message header printed by gulp-prettier before the list of files with errors.
+// See https://github.com/bhargavrpatel/gulp-prettier/blob/master/index.js#L90
+const header =
+  'Code style issues found in the following file(s). Forgot to run Prettier?';
 
 /**
  * Logs the list of files that will be checked.
@@ -61,8 +57,10 @@ function logFiles(files) {
 
 /**
  * Checks files for formatting (and optionally fixes them) with Prettier.
+ *
+ * @return {!Promise}
  */
-async function prettify() {
+function prettify() {
   maybeUpdatePackages();
   let filesToCheck;
   if (argv.files) {
@@ -79,23 +77,33 @@ async function prettify() {
   } else {
     filesToCheck = globby.sync(prettifyGlobs, {dot: true});
   }
-  runPrettify(filesToCheck);
+  return runPrettify(filesToCheck);
 }
 
 /**
- * Runs prettier on the given list of files. Returns the cumulative result to
- * the `gulp` process via  process.exitCode so all files can be checked / fixed.
+ * Runs prettier on the given list of files with gulp-prettier.
  *
  * @param {!Array<string>} filesToCheck
+ * @return {!Promise}
  */
 function runPrettify(filesToCheck) {
   if (!isTravisBuild()) {
     log(green('Starting checks...'));
   }
-  filesToCheck.forEach(checkFile);
-  if (process.exitCode == 1) {
-    logOnSameLine(red('ERROR: ') + 'Found errors in one or more files.');
-    if (!argv.fix) {
+  return new Promise((resolve, reject) => {
+    const onData = data => {
+      if (!isTravisBuild()) {
+        logOnSameLine(green('Checked: ') + path.relative(rootDir, data.path));
+      }
+    };
+
+    const rejectWithReason = reasonText => {
+      const reason = new Error(reasonText);
+      reason.showStack = false;
+      reject(reason);
+    };
+
+    const printFixMessages = () => {
       log(
         yellow('NOTE 1:'),
         'You may be able to automatically fix some errors by running',
@@ -111,59 +119,56 @@ function runPrettify(filesToCheck) {
         yellow('NOTE 3:'),
         'For more information, read',
         cyan(
-          'https://github.com/ampproject/amphtml/blob/master/contributing/getting-started-e2e.md#code-quality-and-style'
+          'https://github.com/ampproject/amphtml/blob/master/contributing/getting-started-e2e.md#code-quality-and-style\n'
         )
       );
-    }
-  } else {
-    if (!isTravisBuild()) {
-      logOnSameLine(green('SUCCESS: ') + 'No formatting errors found.');
-    }
-  }
-}
+    };
 
-/**
- * Fixes the formatting of a single file
- * @param {string} file
- */
-function fixFile(file) {
-  const fixCmd = `${prettierCmd} --write ${file}`;
-  const fixResult = getOutput(fixCmd);
-  if (fixResult.status == PrettierResult.SUCCESS) {
-    logOnSameLine(green('Fixed: ') + file + '\n');
-  } else {
-    logOnSameLine(red('Could not fix: ') + file);
-    console.log(highlight(fixResult.stderr, {ignoreIllegals: true}), '\n');
-    process.exitCode = 1;
-  }
-}
+    const onError = error => {
+      if (error.message.startsWith(header)) {
+        const filesWithErrors = error.message
+          .replace(header, '')
+          .trim()
+          .split('\n');
+        const reason = 'Found formatting errors in one or more files';
+        logOnSameLine(red('ERROR: ') + reason + ':');
+        filesWithErrors.forEach(file => {
+          log(cyan(file));
+        });
+        printFixMessages();
+        rejectWithReason(reason);
+      } else {
+        const reason = 'Found an unrecoverable error';
+        logOnSameLine(red('ERROR: ') + reason + ':');
+        log(error.message);
+        rejectWithReason(reason);
+      }
+    };
+
+    const onFinish = () => {
+      if (!isTravisBuild()) {
+        logOnSameLine('Checked ' + cyan(filesToCheck.length) + ' file(s)');
+      }
+      resolve();
+    };
 
-/**
- * Checks and optionally fixes the formatting of a single file.
- * @param {string} file
- */
-function checkFile(file) {
-  const checkCmd = `${prettierCmd} --list-different ${file}`;
-  const checkResult = getOutput(checkCmd);
-  if (checkResult.status == PrettierResult.SUCCESS) {
-    if (!isTravisBuild()) {
-      logOnSameLine(green('Checked: ') + file);
-    }
-  } else if (checkResult.status == PrettierResult.FAILURE) {
     if (argv.fix) {
-      fixFile(file);
+      return gulp
+        .src(filesToCheck)
+        .pipe(prettier())
+        .on('data', onData)
+        .on('error', onError)
+        .pipe(gulp.dest(file => file.base))
+        .on('finish', onFinish);
     } else {
-      logOnSameLine(red('Found errors in: ') + file + '\n');
-      process.exitCode = 1;
+      return gulp
+        .src(filesToCheck)
+        .pipe(prettier.check())
+        .on('data', onData)
+        .on('error', onError)
+        .on('finish', onFinish);
     }
-  } else {
-    logOnSameLine(red('Could not parse: ') + file);
-    console.log(
-      highlight(checkResult.stderr.trim(), {ignoreIllegals: true}),
-      '\n'
-    );
-    process.exitCode = 1;
-  }
+  });
 }
 
 module.exports = {

package.json

@@ -105,6 +105,7 @@
     "gulp-jsonlint": "1.3.1",
     "gulp-jsonminify": "1.1.0",
     "gulp-nop": "0.0.3",
+    "gulp-prettier": "2.1.0",
     "gulp-regexp-sourcemaps": "1.0.1",
     "gulp-rename": "1.4.0",
     "gulp-sourcemaps": "2.6.5",

yarn.lock

@@ -6244,6 +6244,16 @@ gulp-nop@0.0.3:
     gulp-util "~2.2.14"
     through "~2.3.4"
 
+gulp-prettier@2.1.0:
+  version "2.1.0"
+  resolved "https://registry.yarnpkg.com/gulp-prettier/-/gulp-prettier-2.1.0.tgz#6e7b2a12395315fb9e1ebd4ea9ed9514410aec15"
+  integrity sha512-6PvGPX+x0d1+PbP7tHF42o6zWzxCXqouTnpwZV1GjF47/wAgWBfPU1E6/6d4uAGM+NhmwWdKvIVumL3wMZZxDg==
+  dependencies:
+    plugin-error "^1.0.1"
+    prettier "^1.5.3"
+    safe-buffer "^5.1.2"
+    through2 "^3.0.0"
+
 gulp-regexp-sourcemaps@1.0.1:
   version "1.0.1"
   resolved "https://registry.yarnpkg.com/gulp-regexp-sourcemaps/-/gulp-regexp-sourcemaps-1.0.1.tgz#a8812244852c10950683a948e1c0dad0b1249979"
@@ -10770,7 +10780,7 @@ prettier-linter-helpers@^1.0.0:
   dependencies:
     fast-diff "^1.1.2"
 
-prettier@1.18.2:
+prettier@1.18.2, prettier@^1.5.3:
   version "1.18.2"
   resolved "https://registry.yarnpkg.com/prettier/-/prettier-1.18.2.tgz#6823e7c5900017b4bd3acf46fe9ac4b4d7bda9ea"
   integrity sha512-OeHeMc0JhFE9idD4ZdtNibzY0+TPHSpSSb9h8FqtP+YnoZZ1sl8Vc9b1sasjfymH3SonAF4QcA2+mzHPhMvIiw==