feat: make the loader async

package.json

@@ -7,21 +7,21 @@
   ],
   "main": "lib/index.js",
   "engines": {
-    "node": ">=4"
+    "node": ">= 4"
   },
   "dependencies": {
     "find-cache-dir": "^1.0.0",
     "loader-utils": "^1.0.2",
     "mkdirp": "^0.5.1"
   },
   "peerDependencies": {
-    "@babel/core": "7 || ^7.0.0-beta || ^7.0.0-rc",
-    "webpack": "2 || 3"
+    "@babel/core": "^7.0.0 || ^7.0.0-rc || ^7.0.0-beta.32",
+    "webpack": "^2.0.0 || ^3.0.0"
   },
   "devDependencies": {
-    "@babel/cli": "7.0.0-beta.5",
-    "@babel/core": "7.0.0-beta.5",
-    "@babel/preset-env": "7.0.0-beta.5",
+    "@babel/cli": "7.0.0-beta.32",
+    "@babel/core": "7.0.0-beta.32",
+    "@babel/preset-env": "7.0.0-beta.32",
     "ava": "0.23.0",
     "babel-eslint": "^8.0.0",
     "babel-plugin-istanbul": "^4.0.0",
@@ -44,7 +44,7 @@
   "scripts": {
     "clean": "rimraf lib/",
     "build": "babel src/ --out-dir lib/",
-    "format": "prettier --write --trailing-comma all \"src/**/*.js\" \"test/**/*.test.js\" \"test/helpers/*.js\" && prettier --write --trailing-comma es5 \"scripts/*.js\"",
+    "format": "prettier --write --trailing-comma all 'src/**/*.js' 'test/**/*.test.js' 'test/helpers/*.js' && prettier --write --trailing-comma es5 'scripts/*.js'",
     "lint": "eslint src test",
     "precommit": "lint-staged",
     "prepublish": "yarn run clean && yarn run build",

src/Error.js

@@ -0,0 +1,35 @@
+const STRIP_FILENAME_RE = /^[^:]+: /;
+
+const format = err => {
+  if (err instanceof SyntaxError) {
+    err.name = "SyntaxError";
+    err.message = err.message.replace(STRIP_FILENAME_RE, "");
+
+    err.hideStack = true;
+  } else if (err instanceof TypeError) {
+    err.name = null;
+    err.message = err.message.replace(STRIP_FILENAME_RE, "");
+
+    err.hideStack = true;
+  }
+
+  return err;
+};
+
+class LoaderError extends Error {
+  constructor(err) {
+    super();
+
+    const { name, message, codeFrame, hideStack } = format(err);
+
+    this.name = "BabelLoaderError";
+
+    this.message = `${name ? `${name}: ` : ""}${message}\n\n${codeFrame}\n`;
+
+    this.hideStack = hideStack;
+
+    Error.captureStackTrace(this, this.constructor);
+  }
+}
+
+module.exports = LoaderError;

src/fs-cache.js → src/cache.js

@@ -1,21 +1,23 @@
 /**
- * Filesystem cache
+ * Filesystem Cache
  *
  * Given a file and a transform function, cache the result into files
  * or retrieve the previously cached files if the given file is already known.
  *
  * @see https://github.com/babel/babel-loader/issues/34
  * @see https://github.com/babel/babel-loader/pull/41
  */
-const crypto = require("crypto");
-const mkdirp = require("mkdirp");
-const findCacheDir = require("find-cache-dir");
 const fs = require("fs");
 const os = require("os");
 const path = require("path");
 const zlib = require("zlib");
+const crypto = require("crypto");
+const mkdirp = require("mkdirp");
+const findCacheDir = require("find-cache-dir");
 
-let defaultCacheDirectory = null; // Lazily instantiated when needed
+const transform = require("./transform");
+// Lazily instantiated when needed
+let cacheDirectory = null;
 
 /**
  * Read the contents from the compressed file.
@@ -25,13 +27,13 @@ let defaultCacheDirectory = null; // Lazily instantiated when needed
  * @params {Function} callback
  */
 const read = function(filename, callback) {
-  return fs.readFile(filename, function(err, data) {
+  return fs.readFile(filename, (err, data) => {
     if (err) return callback(err);
 
-    return zlib.gunzip(data, function(err, content) {
+    return zlib.gunzip(data, (err, content) => {
       if (err) return callback(err);
 
-      let result = {};
+      let result = Object.create(null);
 
       try {
         result = JSON.parse(content);
@@ -55,7 +57,7 @@ const read = function(filename, callback) {
 const write = function(filename, result, callback) {
   const content = JSON.stringify(result);
 
-  return zlib.gzip(content, function(err, data) {
+  return zlib.gzip(content, (err, data) => {
     if (err) return callback(err);
 
     return fs.writeFile(filename, data, callback);
@@ -72,11 +74,8 @@ const write = function(filename, result, callback) {
  */
 const filename = function(source, identifier, options) {
   const hash = crypto.createHash("SHA1");
-  const contents = JSON.stringify({
-    source: source,
-    options: options,
-    identifier: identifier,
-  });
+
+  const contents = JSON.stringify({ source, options, identifier });
 
   hash.end(contents);
 
@@ -91,45 +90,45 @@ const filename = function(source, identifier, options) {
  * @params {Function} callback
  */
 const handleCache = function(directory, params, callback) {
-  const source = params.source;
-  const options = params.options || {};
-  const transform = params.transform;
-  const identifier = params.identifier;
-  const shouldFallback =
+  const { source, options = {}, cacheIdentifier } = params;
+
+  const fallback =
     typeof params.directory !== "string" && directory !== os.tmpdir();
 
   // Make sure the directory exists.
-  mkdirp(directory, function(err) {
+  mkdirp(directory, err => {
     // Fallback to tmpdir if node_modules folder not writable
-    if (err)
-      return shouldFallback
+    if (err) {
+      return fallback
         ? handleCache(os.tmpdir(), params, callback)
         : callback(err);
+    }
 
-    const file = path.join(directory, filename(source, identifier, options));
+    const file = path.join(
+      directory,
+      filename(source, cacheIdentifier, options),
+    );
 
-    return read(file, function(err, content) {
-      let result = {};
+    return read(file, (err, content) => {
       // No errors mean that the file was previously cached
       // we just need to return it
       if (!err) return callback(null, content);
 
       // Otherwise just transform the file
       // return it to the user asap and write it in cache
-      try {
-        result = transform(source, options);
-      } catch (error) {
-        return callback(error);
-      }
-
-      return write(file, result, function(err) {
-        // Fallback to tmpdir if node_modules folder not writable
-        if (err)
-          return shouldFallback
-            ? handleCache(os.tmpdir(), params, callback)
-            : callback(err);
-
-        callback(null, result);
+      return transform(source, options, (err, result) => {
+        if (err) return callback(err);
+
+        return write(file, result, err => {
+          // Fallback to tmpdir if node_modules folder not writable
+          if (err) {
+            return fallback
+              ? handleCache(os.tmpdir(), params, callback)
+              : callback(err);
+          }
+
+          return callback(null, result);
+        });
       });
     });
   });
@@ -172,14 +171,14 @@ const handleCache = function(directory, params, callback) {
 module.exports = function(params, callback) {
   let directory;
 
-  if (typeof params.directory === "string") {
-    directory = params.directory;
+  if (typeof params.cacheDirectory === "string") {
+    directory = params.cacheDirectory;
   } else {
-    if (defaultCacheDirectory === null) {
-      defaultCacheDirectory =
-        findCacheDir({ name: "babel-loader" }) || os.tmpdir();
+    if (cacheDirectory === null) {
+      cacheDirectory = findCacheDir({ name: "babel-loader" }) || os.tmpdir();
     }
-    directory = defaultCacheDirectory;
+
+    directory = cacheDirectory;
   }
 
   handleCache(directory, params, callback);

src/config.js

@@ -0,0 +1,26 @@
+const path = require("path");
+const exists = require("./utils/exists");
+
+const configs = [".babelrc", ".babelrc.js", "package.json"];
+
+module.exports = function find(fs, start) {
+  for (let config of configs) {
+    config = path.join(start, config);
+
+    if (exists(fs, config)) {
+      if (
+        path.basename(config) !== "package.json" ||
+        typeof require(config).babel === "object"
+      ) {
+        return config;
+      }
+    }
+  }
+
+  const up = path.dirname(start);
+
+  // Reached root
+  if (up !== start) {
+    return find(fs, up);
+  }
+};