Revert "🏗️🚀 Babel compile with sourcemaps (#27447)"

This reverts commit bcde1ec.

build-system/compile/compile.js

@@ -367,8 +367,8 @@ function compile(
     if (options.typeCheckOnly) {
       return gulp
         .src(srcs, {base: '.'})
-        .pipe(sourcemaps.init())
         .pipe(preClosureBabel())
+        .pipe(sourcemaps.init({loadMaps: true}))
         .pipe(gulpClosureCompile(compilerOptionsArray, checkTypesNailgunPort))
         .on('error', err => {
           handleTypeCheckError();
@@ -380,8 +380,8 @@ function compile(
       timeInfo.startTime = Date.now();
       return gulp
         .src(srcs, {base: '.'})
-        .pipe(sourcemaps.init())
         .pipe(preClosureBabel())
+        .pipe(sourcemaps.init({loadMaps: true}))
         .pipe(gulpClosureCompile(compilerOptionsArray, distNailgunPort))
         .on('error', err => {
           handleCompilerError(outputFilename);

build-system/compile/pre-closure-babel.js

@@ -16,13 +16,15 @@
 'use strict';
 
 const argv = require('minimist')(process.argv.slice(2));
+const babel = require('@babel/core');
 const conf = require('./build.conf');
-const crypto = require('crypto');
 const globby = require('globby');
-const gulpBabel = require('gulp-babel');
+const path = require('path');
 const through = require('through2');
 const {BABEL_SRC_GLOBS, THIRD_PARTY_TRANSFORM_GLOBS} = require('./sources');
 
+const ROOT_DIR = path.resolve(__dirname, '../../');
+
 /**
  * Files on which to run pre-closure babel transforms.
  *
@@ -35,7 +37,7 @@ const filesToTransform = getFilesToTransform();
  *
  * @private @const {!Object<string, string>}
  */
-const cache = Object.create(null);
+const cachedTransforms = {};
 
 /**
  * Computes the set of files on which to run pre-closure babel transforms.
@@ -48,16 +50,6 @@ function getFilesToTransform() {
     .concat(globby.sync(THIRD_PARTY_TRANSFORM_GLOBS));
 }
 
-/**
- * @param {!Buffer} contents
- * @return {string}
- */
-function sha256(contents) {
-  const hash = crypto.createHash('sha256');
-  hash.update(contents);
-  return hash.digest('hex');
-}
-
 /**
  * Apply babel transforms prior to closure compiler pass.
  *
@@ -68,52 +60,26 @@ function sha256(contents) {
  * @return {!Promise}
  */
 function preClosureBabel() {
-  const babelPlugins = conf.plugins({
-    isForTesting: !!argv.fortesting,
-    isEsmBuild: !!argv.esm,
-    isSinglePass: !!argv.single_pass,
-    isChecktypes: argv._.includes('check-types'),
-  });
-  const babel = gulpBabel({
-    plugins: babelPlugins,
-    retainLines: true,
-    compact: false,
-  });
-
   return through.obj((file, enc, next) => {
-    const {relative, path} = file;
-    if (!filesToTransform.includes(relative)) {
-      return next(null, file);
-    }
-
-    const hash = sha256(file.contents);
-    const cached = cache[path];
-    if (cached && cached.hash === hash) {
-      return next(null, cached.file.clone());
+    const cachedTransform = cachedTransforms[file.path];
+    if (cachedTransform) {
+      file.contents = Buffer.from(cachedTransform);
+    } else if (filesToTransform.includes(path.relative(ROOT_DIR, file.path))) {
+      const babelPlugins = conf.plugins({
+        isForTesting: !!argv.fortesting,
+        isEsmBuild: !!argv.esm,
+        isSinglePass: !!argv.single_pass,
+        isChecktypes: argv._.includes('check-types'),
+      });
+      const {code} = babel.transformFileSync(file.path, {
+        plugins: babelPlugins,
+        retainLines: true,
+        compact: false,
+      });
+      cachedTransforms[file.path] = code;
+      file.contents = Buffer.from(code);
     }
-
-    let data, err;
-    function onData(d) {
-      babel.off('error', onError);
-      data = d;
-    }
-    function onError(e) {
-      babel.off('data', onData);
-      err = e;
-    }
-    babel.once('data', onData);
-    babel.once('error', onError);
-    babel.write(file, enc, () => {
-      if (err) {
-        return next(err);
-      }
-
-      cache[path] = {
-        file: data,
-        hash,
-      };
-      next(null, data.clone());
-    });
+    return next(null, file);
   });
 }
 

build-system/compile/single-pass.js

@@ -686,8 +686,8 @@ function compile(flagsArray) {
   return new Promise(function(resolve, reject) {
     gulp
       .src(srcs, {base: '.'})
-      .pipe(sourcemaps.init())
       .pipe(preClosureBabel())
+      .pipe(sourcemaps.init({loadMaps: true}))
       .pipe(gulpClosureCompile(flagsArray))
       .on('error', err => {
         handleSinglePassCompilerError();

package.json

@@ -94,7 +94,6 @@
     "gulp": "4.0.2",
     "gulp-append-prepend": "1.0.8",
     "gulp-ava": "3.0.0",
-    "gulp-babel": "8.0.0",
     "gulp-connect": "5.7.0",
     "gulp-eslint": "6.0.0",
     "gulp-eslint-if-fixed": "1.0.0",
@@ -182,8 +181,8 @@
     "typescript": "3.8.3",
     "uglifyify": "5.0.2",
     "vinyl-buffer": "1.0.1",
-    "vinyl-source-stream": "2.0.0",
     "vinyl-sourcemaps-apply": "0.2.1",
+    "vinyl-source-stream": "2.0.0",
     "watchify": "3.11.1"
   },
   "filesize": {

yarn.lock

@@ -7831,16 +7831,6 @@ gulp-ava@3.0.0:
     resolve-cwd "^3.0.0"
     through2 "^3.0.0"
 
-gulp-babel@8.0.0:
-  version "8.0.0"
-  resolved "https://registry.yarnpkg.com/gulp-babel/-/gulp-babel-8.0.0.tgz#e0da96f4f2ec4a88dd3a3030f476e38ab2126d87"
-  integrity sha512-oomaIqDXxFkg7lbpBou/gnUkX51/Y/M2ZfSjL2hdqXTAlSWZcgZtd2o0cOH0r/eE8LWD0+Q/PsLsr2DKOoqToQ==
-  dependencies:
-    plugin-error "^1.0.1"
-    replace-ext "^1.0.0"
-    through2 "^2.0.0"
-    vinyl-sourcemaps-apply "^0.2.0"
-
 gulp-cli@^2.2.0:
   version "2.2.0"
   resolved "https://registry.yarnpkg.com/gulp-cli/-/gulp-cli-2.2.0.tgz#5533126eeb7fe415a7e3e84a297d334d5cf70ebc"