Add a promise-returning *Async version of the transform and parse fns

packages/babel-core/package.json

@@ -27,8 +27,7 @@
   },
   "browser": {
     "./lib/config/files/index.js": "./lib/config/files/index-browser.js",
-    "./lib/transform-file.js": "./lib/transform-file-browser.js",
-    "./lib/transform-file-sync.js": "./lib/transform-file-sync-browser.js"
+    "./lib/transform-file.js": "./lib/transform-file-browser.js"
   },
   "dependencies": {
     "@babel/code-frame": "7.0.0-beta.47",

packages/babel-core/src/config/index.js

@@ -17,10 +17,3 @@ export function loadOptions(opts: {}): Object | null {
 
   return config ? config.options : null;
 }
-
-// For easier backward-compatibility, provide an API like the one we exposed in Babel 6.
-export class OptionManager {
-  init(opts: {}) {
-    return loadOptions(opts);
-  }
-}

packages/babel-core/src/index.js

@@ -13,26 +13,22 @@ export * as types from "@babel/types";
 export { default as traverse } from "@babel/traverse";
 export { default as template } from "@babel/template";
 
-export { loadPartialConfig, loadOptions, OptionManager } from "./config";
-
 export { createConfigItem } from "./config/item";
 
-export function Plugin(alias: string) {
-  throw new Error(
-    `The (${alias}) Babel 5 plugin is being run with an unsupported Babel version.`,
-  );
-}
-
-export { default as transform } from "./transform";
-export { default as transformSync } from "./transform-sync";
-
-export { default as transformFile } from "./transform-file";
-export { default as transformFileSync } from "./transform-file-sync";
+export { loadPartialConfig, loadOptions } from "./config";
 
-export { default as transformFromAst } from "./transform-ast";
-export { default as transformFromAstSync } from "./transform-ast-sync";
-
-export { default as parse } from "./parse";
+export { transform, transformSync, transformAsync } from "./transform";
+export {
+  transformFile,
+  transformFileSync,
+  transformFileAsync,
+} from "./transform-file";
+export {
+  transformFromAst,
+  transformFromAstSync,
+  transformFromAstAsync,
+} from "./transform-ast";
+export { parse, parseSync, parseAsync } from "./parse";
 
 /**
  * Recommended set of compilable extensions. Not used in @babel/core directly, but meant as
@@ -45,3 +41,17 @@ export const DEFAULT_EXTENSIONS = Object.freeze([
   ".es",
   ".mjs",
 ]);
+
+// For easier backward-compatibility, provide an API like the one we exposed in Babel 6.
+import { loadOptions } from "./config";
+export class OptionManager {
+  init(opts: {}) {
+    return loadOptions(opts);
+  }
+}
+
+export function Plugin(alias: string) {
+  throw new Error(
+    `The (${alias}) Babel 5 plugin is being run with an unsupported Babel version.`,
+  );
+}

packages/babel-core/src/parse.js

@@ -6,17 +6,79 @@ import normalizeOptions from "./transformation/normalize-opts";
 
 type AstRoot = BabelNodeFile | BabelNodeProgram;
 
-export default function parse(
+export type ParseResult = AstRoot;
+
+export type FileParseCallback = {
+  (Error, null): any,
+  (null, ParseResult | null): any,
+};
+
+type Parse = {
+  (code: string, callback: FileParseCallback): void,
+  (code: string, opts: ?InputOptions, callback: FileParseCallback): void,
+
+  // Here for backward-compatibility. Ideally use ".parseSync" if you want
+  // a synchronous API.
+  (code: string, opts: ?InputOptions): ParseResult | null,
+};
+
+export const parse: Parse = (function parse(code, opts, callback) {
+  if (typeof opts === "function") {
+    opts = undefined;
+    callback = opts;
+  }
+
+  // For backward-compat with Babel 7's early betas, we allow sync parsing when
+  // no callback is given. Will be dropped in some future Babel major version.
+  if (callback === undefined) return parseSync(code, opts);
+
+  const config = loadConfig(opts);
+
+  if (config === null) {
+    return null;
+  }
+
+  // Reassign to keep Flowtype happy.
+  const cb = callback;
+
+  // Just delaying the transform one tick for now to simulate async behavior
+  // but more async logic may land here eventually.
+  process.nextTick(() => {
+    let ast = null;
+    try {
+      const cfg = loadConfig(opts);
+      if (cfg === null) return cb(null, null);
+
+      ast = normalizeFile(cfg.passes, normalizeOptions(cfg), code).ast;
+    } catch (err) {
+      return cb(err);
+    }
+
+    cb(null, ast);
+  });
+}: Function);
+
+export function parseSync(
   code: string,
-  opts: InputOptions,
-): AstRoot | null {
+  opts?: InputOptions,
+): ParseResult | null {
   const config = loadConfig(opts);
 
   if (config === null) {
     return null;
   }
 
-  const file = normalizeFile(config.passes, normalizeOptions(config), code);
+  return normalizeFile(config.passes, normalizeOptions(config), code).ast;
+}
 
-  return file.ast;
+export function parseAsync(
+  code: string,
+  opts?: InputOptions,
+): Promise<ParseResult | null> {
+  return new Promise((res, rej) => {
+    parse(code, opts, (err, result) => {
+      if (err == null) res(result);
+      else rej(err);
+    });
+  });
 }

packages/babel-core/src/transform-ast.js

@@ -2,16 +2,15 @@
 
 import loadConfig, { type InputOptions } from "./config";
 import {
+  runSync,
   runAsync,
   type FileResult,
   type FileResultCallback,
 } from "./transformation";
 
-import transformAstSync from "./transform-ast-sync";
-
 type AstRoot = BabelNodeFile | BabelNodeProgram;
 
-type TransformAst = {
+type TransformFromAst = {
   (ast: AstRoot, code: string, callback: FileResultCallback): void,
   (
     ast: AstRoot,
@@ -25,15 +24,20 @@ type TransformAst = {
   (ast: AstRoot, code: string, opts: ?InputOptions): FileResult | null,
 };
 
-export default ((function transformFromAst(ast, code, opts, callback) {
+export const transformFromAst: TransformFromAst = (function transformFromAst(
+  ast,
+  code,
+  opts,
+  callback,
+) {
   if (typeof opts === "function") {
     opts = undefined;
     callback = opts;
   }
 
   // For backward-compat with Babel 6, we allow sync transformation when
   // no callback is given. Will be dropped in some future Babel major version.
-  if (callback === undefined) return transformAstSync(ast, code, opts);
+  if (callback === undefined) return transformFromAstSync(ast, code, opts);
 
   // Reassign to keep Flowtype happy.
   const cb = callback;
@@ -53,4 +57,30 @@ export default ((function transformFromAst(ast, code, opts, callback) {
 
     runAsync(cfg, code, ast, cb);
   });
-}: Function): TransformAst);
+}: Function);
+
+export function transformFromAstSync(
+  ast: AstRoot,
+  code: string,
+  opts: ?InputOptions,
+): FileResult | null {
+  const config = loadConfig(opts);
+  if (config === null) return null;
+
+  if (!ast) throw new Error("No AST given");
+
+  return runSync(config, code, ast);
+}
+
+export function transformFromAstAsync(
+  ast: AstRoot,
+  code: string,
+  opts: ?InputOptions,
+): Promise<FileResult | null> {
+  return new Promise((res, rej) => {
+    transformFromAst(ast, code, opts, (err, result) => {
+      if (err == null) res(result);
+      else rej(err);
+    });
+  });
+}

packages/babel-core/src/transform-file.js

@@ -2,14 +2,23 @@
 import fs from "fs";
 
 import loadConfig, { type InputOptions } from "./config";
-import { runAsync, type FileResultCallback } from "./transformation";
+import {
+  runSync,
+  runAsync,
+  type FileResult,
+  type FileResultCallback,
+} from "./transformation";
 
 type TransformFile = {
   (filename: string, callback: FileResultCallback): void,
   (filename: string, opts: ?InputOptions, callback: FileResultCallback): void,
 };
 
-export default ((function transformFile(filename, opts, callback) {
+export const transformFile: TransformFile = (function transformFile(
+  filename,
+  opts,
+  callback,
+) {
   let options;
   if (typeof opts === "function") {
     callback = opts;
@@ -43,4 +52,36 @@ export default ((function transformFile(filename, opts, callback) {
       runAsync(config, code, null, callback);
     });
   });
-}: Function): TransformFile);
+}: Function);
+
+export function transformFileSync(
+  filename: string,
+  opts: ?InputOptions,
+): FileResult | null {
+  let options;
+  if (opts == null) {
+    options = { filename };
+  } else if (opts && typeof opts === "object") {
+    options = {
+      ...opts,
+      filename,
+    };
+  }
+
+  const config = loadConfig(options);
+  if (config === null) return null;
+
+  return runSync(config, fs.readFileSync(filename, "utf8"));
+}
+
+export function transformFileAsync(
+  filename: string,
+  opts: ?InputOptions,
+): Promise<FileResult | null> {
+  return new Promise((res, rej) => {
+    transformFile(filename, opts, (err, result) => {
+      if (err == null) res(result);
+      else rej(err);
+    });
+  });
+}