Merge pull request #4892 from kaicataldo/babelrcjs

Add support for .babelrc.js files

packages/babel-core/src/transformation/file/options/build-config-chain.js

@@ -1,4 +1,3 @@
-
 import type Logger from "../logger";
 import resolve from "../../../helpers/resolve";
 import json5 from "json5";
@@ -8,9 +7,10 @@ import fs from "fs";
 const existsCache = {};
 const jsonCache = {};
 
-const BABELIGNORE_FILENAME = ".babelignore";
 const BABELRC_FILENAME = ".babelrc";
+const BABELRC_JS_FILENAME = ".babelrc.js";
 const PACKAGE_FILENAME = "package.json";
+const BABELIGNORE_FILENAME = ".babelignore";
 
 function exists(filename) {
   const cached = existsCache[filename];
@@ -46,7 +46,12 @@ class ConfigChainBuilder {
     this.log = log;
   }
 
-  findConfigs(loc) {
+  errorMultipleConfigs(loc1: string, loc2: string) {
+    throw new Error(`Multiple configuration files found. Please remove one:\n- ${
+      loc1}\n- ${loc2}`);
+  }
+
+  findConfigs(loc: string) {
     if (!loc) return;
 
     if (!path.isAbsolute(loc)) {
@@ -59,15 +64,26 @@ class ConfigChainBuilder {
     while (loc !== (loc = path.dirname(loc))) {
       if (!foundConfig) {
         const configLoc = path.join(loc, BABELRC_FILENAME);
-        if (exists(configLoc)) {
-          this.addConfig(configLoc);
-          foundConfig = true;
-        }
-
+        const configJSLoc = path.join(loc, BABELRC_JS_FILENAME);
         const pkgLoc = path.join(loc, PACKAGE_FILENAME);
-        if (!foundConfig && exists(pkgLoc)) {
-          foundConfig = this.addConfig(pkgLoc, "babel", JSON);
-        }
+        const configLocs = [configLoc, configJSLoc, pkgLoc];
+        const foundConfigs = configLocs.reduce((arr, config) => {
+          if (exists(config)) {
+            const configAdded = config === pkgLoc
+              ? this.addConfig(config, "babel", JSON)
+              : this.addConfig(config);
+
+            if (configAdded && arr.length) {
+              this.errorMultipleConfigs(arr.pop(), config);
+            }
+
+            arr.push(config);
+          }
+
+          return arr;
+        }, []);
+
+        foundConfig = !!foundConfigs.length;
       }
 
       if (!foundIgnore) {
@@ -82,7 +98,7 @@ class ConfigChainBuilder {
     }
   }
 
-  addIgnoreConfig(loc) {
+  addIgnoreConfig(loc: string) {
     const file = fs.readFileSync(loc, "utf8");
     let lines = file.split("\n");
 
@@ -106,15 +122,35 @@ class ConfigChainBuilder {
 
     this.resolvedConfigs.push(loc);
 
-    const content = fs.readFileSync(loc, "utf8");
     let options;
+    if (path.extname(loc) === ".js") {
+      try {
+        const configModule = require(loc);
+        options = configModule && configModule.__esModule ? configModule.default : configModule;
+      } catch (err) {
+        err.message = `${loc}: Error while loading config - ${err.message}`;
+        throw err;
+      }
 
-    try {
-      options = jsonCache[content] = jsonCache[content] || json.parse(content);
-      if (key) options = options[key];
-    } catch (err) {
-      err.message = `${loc}: Error while parsing JSON - ${err.message}`;
-      throw err;
+      if (!options || typeof options !== "object") {
+        throw new Error("Configuration should be an exported JavaScript object.");
+      }
+    } else {
+      const content = fs.readFileSync(loc, "utf8");
+      try {
+        options = jsonCache[content] = jsonCache[content] || json.parse(content);
+      } catch (err) {
+        err.message = `${loc}: Error while parsing JSON - ${err.message}`;
+        throw err;
+      }
+    }
+
+    if (key) {
+      if (!options[key]) {
+        return false;
+      }
+
+      options = options[key];
     }
 
     this.mergeConfig({

packages/babel-core/test/config-chain.js

@@ -294,4 +294,253 @@ describe("buildConfigChain", function () {
 
     assert.deepEqual(chain, expected);
   });
+
+  it("js-config", function () {
+    const chain = buildConfigChain({
+      filename: fixture("js-config", "src.js"),
+    });
+
+    const expected = [
+      {
+        options: {
+          plugins: [
+            "foo",
+            "bar",
+          ],
+        },
+        alias: fixture("js-config", ".babelrc.js"),
+        loc: fixture("js-config", ".babelrc.js"),
+        dirname: fixture("js-config"),
+      },
+      {
+        options: {
+          ignore: [
+            "root-ignore",
+          ],
+        },
+        alias: fixture(".babelignore"),
+        loc: fixture(".babelignore"),
+        dirname: fixture(),
+      },
+      {
+        options: {
+          filename: fixture("js-config", "src.js"),
+        },
+        alias: "base",
+        loc: "base",
+        dirname: fixture("js-config"),
+      },
+    ];
+
+    assert.deepEqual(chain, expected);
+  });
+
+  it("js-config-default - should read transpiled export default", function () {
+    const chain = buildConfigChain({
+      filename: fixture("js-config-default", "src.js"),
+    });
+
+    const expected = [
+      {
+        options: {
+          plugins: [
+            "foo",
+            "bar",
+          ],
+        },
+        alias: fixture("js-config-default", ".babelrc.js"),
+        loc: fixture("js-config-default", ".babelrc.js"),
+        dirname: fixture("js-config-default"),
+      },
+      {
+        options: {
+          ignore: [
+            "root-ignore",
+          ],
+        },
+        alias: fixture(".babelignore"),
+        loc: fixture(".babelignore"),
+        dirname: fixture(),
+      },
+      {
+        options: {
+          filename: fixture("js-config-default", "src.js"),
+        },
+        alias: "base",
+        loc: "base",
+        dirname: fixture("js-config-default"),
+      },
+    ];
+
+    assert.deepEqual(chain, expected);
+  });
+  it("js-config-extended", function () {
+    const chain = buildConfigChain({
+      filename: fixture("js-config-extended", "src.js"),
+    });
+
+    const expected = [
+      {
+        options: {
+          plugins: [
+            "extended",
+          ],
+        },
+        alias: fixture("extended.babelrc.json"),
+        loc: fixture("extended.babelrc.json"),
+        dirname: fixture(),
+      },
+      {
+        options: {
+          plugins: [
+            "foo",
+            "bar",
+          ],
+        },
+        alias: fixture("js-config-extended", ".babelrc.js"),
+        loc: fixture("js-config-extended", ".babelrc.js"),
+        dirname: fixture("js-config-extended"),
+      },
+      {
+        options: {
+          ignore: [
+            "root-ignore",
+          ],
+        },
+        alias: fixture(".babelignore"),
+        loc: fixture(".babelignore"),
+        dirname: fixture(),
+      },
+      {
+        options: {
+          filename: fixture("js-config-extended", "src.js"),
+        },
+        alias: "base",
+        loc: "base",
+        dirname: fixture("js-config-extended"),
+      },
+    ];
+
+    assert.deepEqual(chain, expected);
+  });
+
+  it("json-pkg-config-no-babel - should not throw if" +
+    " package.json doesn't contain a `babel` field", function () {
+    const chain = buildConfigChain({
+      filename: fixture("json-pkg-config-no-babel", "src.js"),
+    });
+
+    const expected = [
+      {
+        options: {
+          plugins: [
+            "json",
+          ],
+        },
+        alias: fixture("json-pkg-config-no-babel", ".babelrc"),
+        loc: fixture("json-pkg-config-no-babel", ".babelrc"),
+        dirname: fixture("json-pkg-config-no-babel"),
+      },
+      {
+        options: {
+          ignore: [
+            "root-ignore",
+          ],
+        },
+        alias: fixture(".babelignore"),
+        loc: fixture(".babelignore"),
+        dirname: fixture(),
+      },
+      {
+        options: {
+          filename: fixture("json-pkg-config-no-babel", "src.js"),
+        },
+        alias: "base",
+        loc: "base",
+        dirname: fixture("json-pkg-config-no-babel"),
+      },
+    ];
+
+    assert.deepEqual(chain, expected);
+  });
+
+  it("js-json-config - should throw an error if both a .babelrc" +
+    " and a .babelrc.js are present", function () {
+    assert.throws(
+      function () {
+        buildConfigChain({
+          filename: fixture("js-json-config", "src.js"),
+        });
+      },
+      /Multiple configuration files found\.(.|\n)*\.babelrc(.|\n)*\.babelrc\.js/
+    );
+  });
+
+  it("js-pkg-config - should throw an error if both a .babelrc.js" +
+    " and a package.json with a babel field are present", function () {
+    assert.throws(
+      function () {
+        buildConfigChain({
+          filename: fixture("js-pkg-config", "src.js"),
+        });
+      },
+      /Multiple configuration files found\.(.|\n)*\.babelrc\.js(.|\n)*package\.json/
+    );
+  });
+
+  it("json-pkg-config - should throw an error if both a .babelrc" +
+    " and a package.json with a babel field are present", function () {
+    assert.throws(
+      function () {
+        buildConfigChain({
+          filename: fixture("json-pkg-config", "src.js"),
+        });
+      },
+      /Multiple configuration files found\.(.|\n)*\.babelrc(.|\n)*package\.json/
+    );
+  });
+
+  it("js-config-error", function () {
+    assert.throws(
+      function () {
+        buildConfigChain({
+          filename: fixture("js-config-error", "src.js"),
+        });
+      },
+      /Error while loading config/
+    );
+  });
+
+  it("js-config-error2", function () {
+    assert.throws(
+      function () {
+        buildConfigChain({
+          filename: fixture("js-config-error2", "src.js"),
+        });
+      },
+      /Configuration should be an exported JavaScript object/
+    );
+  });
+
+  it("js-config-error3", function () {
+    assert.throws(
+      function () {
+        buildConfigChain({
+          filename: fixture("js-config-error3", "src.js"),
+        });
+      },
+      /Configuration should be an exported JavaScript object/
+    );
+  });
+
+  it("json-config-error", function () {
+    assert.throws(
+      function () {
+        buildConfigChain({
+          filename: fixture("json-config-error", "src.js"),
+        });
+      },
+      /Error while parsing JSON/
+    );
+  });
 });

packages/babel-core/test/fixtures/config/js-config-default/.babelrc.js

@@ -0,0 +1,10 @@
+"use strict";
+
+Object.defineProperty(exports, "__esModule", {
+  value: true
+});
+var plugins = ["foo", "bar"];
+
+exports.default = {
+  plugins: plugins
+};

packages/babel-core/test/fixtures/config/js-config-default/src.js

@@ -0,0 +1 @@
+// empty

packages/babel-core/test/fixtures/config/js-config-error/.babelrc.js

@@ -0,0 +1,2 @@
+throw new Error("Something bad happened!");
+module.exports = {}

packages/babel-core/test/fixtures/config/js-config-error/src.js

@@ -0,0 +1 @@
+// empty

packages/babel-core/test/fixtures/config/js-config-error2/.babelrc.js

@@ -0,0 +1 @@
+module.exports = '';

packages/babel-core/test/fixtures/config/js-config-error2/src.js

@@ -0,0 +1 @@
+// empty

packages/babel-core/test/fixtures/config/js-config-error3/.babelrc.js

@@ -0,0 +1 @@
+module.exports = null;

packages/babel-core/test/fixtures/config/js-config-error3/src.js

@@ -0,0 +1 @@
+// empty

packages/babel-core/test/fixtures/config/js-config-extended/.babelrc.js

@@ -0,0 +1,6 @@
+var plugins = ["foo", "bar"];
+
+module.exports = {
+  extends: "../extended.babelrc.json",
+  plugins: plugins
+}

packages/babel-core/test/fixtures/config/js-config-extended/src.js

@@ -0,0 +1 @@
+// empty

packages/babel-core/test/fixtures/config/js-config/.babelrc.js

@@ -0,0 +1,5 @@
+var plugins = ["foo", "bar"];
+
+module.exports = {
+  plugins: plugins
+}

packages/babel-core/test/fixtures/config/js-config/src.js

@@ -0,0 +1 @@
+// empty

packages/babel-core/test/fixtures/config/js-json-config/.babelrc

@@ -0,0 +1,5 @@
+{
+  "plugins": [
+    "json"
+  ]
+}

packages/babel-core/test/fixtures/config/js-json-config/.babelrc.js

@@ -0,0 +1,5 @@
+module.exports = {
+  plugins: [
+    "js"
+  ]
+}

packages/babel-core/test/fixtures/config/js-json-config/src.js

@@ -0,0 +1 @@
+// empty

packages/babel-core/test/fixtures/config/js-pkg-config/.babelrc.js

@@ -0,0 +1,5 @@
+module.exports = {
+  plugins: [
+    "js"
+  ]
+}

packages/babel-core/test/fixtures/config/js-pkg-config/package.json

@@ -0,0 +1,3 @@
+{
+  "babel": {}
+}

packages/babel-core/test/fixtures/config/js-pkg-config/src.js

@@ -0,0 +1 @@
+// empty

packages/babel-core/test/fixtures/config/json-config-error/.babelrc

@@ -0,0 +1,3 @@
+{
+  "bad: "json"
+}

packages/babel-core/test/fixtures/config/json-config-error/src.js

@@ -0,0 +1 @@
+// empty

packages/babel-core/test/fixtures/config/json-pkg-config-no-babel/.babelrc

@@ -0,0 +1,5 @@
+{
+  "plugins": [
+    "json"
+  ]
+}

packages/babel-core/test/fixtures/config/json-pkg-config-no-babel/package.json

@@ -0,0 +1 @@
+{}

packages/babel-core/test/fixtures/config/json-pkg-config-no-babel/src.js

@@ -0,0 +1 @@
+// empty

packages/babel-core/test/fixtures/config/json-pkg-config/.babelrc

@@ -0,0 +1,5 @@
+{
+  "plugins": [
+    "json"
+  ]
+}

packages/babel-core/test/fixtures/config/json-pkg-config/package.json

@@ -0,0 +1,3 @@
+{
+  "babel": {}
+}

packages/babel-core/test/fixtures/config/json-pkg-config/src.js

@@ -0,0 +1 @@
+// empty

packages/babel-generator/src/index.js

@@ -10,9 +10,7 @@ import type { Format } from "./printer";
  */
 
 class Generator extends Printer {
-  constructor(ast, opts, code) {
-    opts = opts || {};
-
+  constructor(ast, opts = {}, code) {
     const tokens = ast.tokens || [];
     const format = normalizeOptions(code, opts, tokens);
     const map = opts.sourceMaps ? new SourceMap(opts, code) : null;

packages/babel-generator/src/node/parentheses.js

@@ -34,12 +34,8 @@ export function NullableTypeAnnotation(node: Object, parent: Object): boolean {
 export { NullableTypeAnnotation as FunctionTypeAnnotation };
 
 export function UpdateExpression(node: Object, parent: Object): boolean {
-  if (t.isMemberExpression(parent) && parent.object === node) {
-    // (foo++).test()
-    return true;
-  }
-
-  return false;
+  // (foo++).test()
+  return t.isMemberExpression(parent) && parent.object === node;
 }
 
 export function ObjectExpression(node: Object, parent: Object, printStack: Array<Object>): boolean {
@@ -51,15 +47,11 @@ export function DoExpression(node: Object, parent: Object, printStack: Array<Obj
 }
 
 export function Binary(node: Object, parent: Object): boolean {
-  if ((t.isCallExpression(parent) || t.isNewExpression(parent)) && parent.callee === node) {
-    return true;
-  }
-
-  if (t.isUnaryLike(parent)) {
-    return true;
-  }
-
-  if (t.isMemberExpression(parent) && parent.object === node) {
+  if (
+    ((t.isCallExpression(parent) || t.isNewExpression(parent)) && parent.callee === node) ||
+    t.isUnaryLike(parent) ||
+    (t.isMemberExpression(parent) && parent.object === node)
+  ) {
     return true;
   }
 
@@ -70,12 +62,11 @@ export function Binary(node: Object, parent: Object): boolean {
     const nodeOp = node.operator;
     const nodePos = PRECEDENCE[nodeOp];
 
-    if (parentPos > nodePos) {
-      return true;
-    }
-
-    // Logical expressions with the same precedence don't need parens.
-    if (parentPos === nodePos && parent.right === node && !t.isLogicalExpression(parent)) {
+    if (
+      // Logical expressions with the same precedence don't need parens.
+      (parentPos === nodePos && parent.right === node && !t.isLogicalExpression(parent)) ||
+      parentPos > nodePos
+    ) {
       return true;
     }
   }
@@ -84,55 +75,27 @@ export function Binary(node: Object, parent: Object): boolean {
 }
 
 export function BinaryExpression(node: Object, parent: Object): boolean {
-  if (node.operator === "in") {
-    // let i = (1 in []);
-    if (t.isVariableDeclarator(parent)) {
-      return true;
-    }
-
-    // for ((1 in []);;);
-    if (t.isFor(parent)) {
-      return true;
-    }
-  }
-
-  return false;
+  // let i = (1 in []);
+  // for ((1 in []);;);
+  return node.operator === "in" && (t.isVariableDeclarator(parent) || t.isFor(parent));
 }
 
 export function SequenceExpression(node: Object, parent: Object): boolean {
-  if (t.isForStatement(parent)) {
+
+  if (
     // Although parentheses wouldn"t hurt around sequence
     // expressions in the head of for loops, traditional style
     // dictates that e.g. i++, j++ should not be wrapped with
     // parentheses.
-    return false;
-  }
-
-  if (t.isExpressionStatement(parent) && parent.expression === node) {
-    return false;
-  }
-
-  if (t.isReturnStatement(parent)) {
-    return false;
-  }
-
-  if (t.isThrowStatement(parent)) {
-    return false;
-  }
-
-  if (t.isSwitchStatement(parent) && parent.discriminant === node) {
-    return false;
-  }
-
-  if (t.isWhileStatement(parent) && parent.test === node) {
-    return false;
-  }
-
-  if (t.isIfStatement(parent) && parent.test === node) {
-    return false;
-  }
-
-  if (t.isForInStatement(parent) && parent.right === node) {
+    t.isForStatement(parent) ||
+    t.isThrowStatement(parent) ||
+    t.isReturnStatement(parent) ||
+    (t.isIfStatement(parent) && parent.test === node) ||
+    (t.isWhileStatement(parent) && parent.test === node) ||
+    (t.isForInStatement(parent) && parent.right === node) ||
+    (t.isSwitchStatement(parent) && parent.discriminant === node) ||
+    (t.isExpressionStatement(parent) && parent.expression === node)
+  ) {
     return false;
   }
 
@@ -158,15 +121,9 @@ export function ClassExpression(node: Object, parent: Object, printStack: Array<
 }
 
 export function UnaryLike(node: Object, parent: Object): boolean {
-  if (t.isMemberExpression(parent, { object: node })) {
-    return true;
-  }
-
-  if (t.isCallExpression(parent, { callee: node }) || t.isNewExpression(parent, { callee: node })) {
-    return true;
-  }
-
-  return false;
+  return t.isMemberExpression(parent, { object: node }) ||
+         t.isCallExpression(parent, { callee: node }) ||
+         t.isNewExpression(parent, { callee: node });
 }
 
 export function FunctionExpression(node: Object, parent: Object, printStack: Array<Object>): boolean {
@@ -189,19 +146,12 @@ export function ArrowFunctionExpression(node: Object, parent: Object): boolean {
 }
 
 export function ConditionalExpression(node: Object, parent: Object): boolean {
-  if (t.isUnaryLike(parent)) {
-    return true;
-  }
-
-  if (t.isBinary(parent)) {
-    return true;
-  }
-
-  if (t.isConditionalExpression(parent, { test: node })) {
-    return true;
-  }
-
-  if (t.isAwaitExpression(parent)) {
+  if (
+    t.isUnaryLike(parent) ||
+    t.isBinary(parent) ||
+    t.isConditionalExpression(parent, { test: node }) ||
+    t.isAwaitExpression(parent)
+  ) {
     return true;
   }
 
@@ -227,28 +177,23 @@ function isFirstInStatement(printStack: Array<Object>, {
   i--;
   let parent = printStack[i];
   while (i > 0) {
-    if (t.isExpressionStatement(parent, { expression: node })) {
+    if (
+      t.isExpressionStatement(parent, { expression: node }) ||
+      t.isTaggedTemplateExpression(parent) ||
+      considerDefaultExports && t.isExportDefaultDeclaration(parent, { declaration: node }) ||
+      considerArrow && t.isArrowFunctionExpression(parent, { body: node })
+    ) {
       return true;
     }
 
-    if (t.isTaggedTemplateExpression(parent)) {
-      return true;
-    }
-
-    if (considerDefaultExports && t.isExportDefaultDeclaration(parent, { declaration: node })) {
-      return true;
-    }
-
-    if (considerArrow && t.isArrowFunctionExpression(parent, { body: node })) {
-      return true;
-    }
-
-    if ((t.isCallExpression(parent, { callee: node })) ||
-        (t.isSequenceExpression(parent) && parent.expressions[0] === node) ||
-        (t.isMemberExpression(parent, { object: node })) ||
-        (t.isConditional(parent, { test: node })) ||
-        (t.isBinary(parent, { left: node })) ||
-        (t.isAssignmentExpression(parent, { left: node }))) {
+    if (
+      t.isCallExpression(parent, { callee: node }) ||
+      (t.isSequenceExpression(parent) && parent.expressions[0] === node) ||
+      t.isMemberExpression(parent, { object: node }) ||
+      t.isConditional(parent, { test: node }) ||
+      t.isBinary(parent, { left: node }) ||
+      t.isAssignmentExpression(parent, { left: node })
+    ) {
       node = parent;
       i--;
       parent = printStack[i];

packages/babel-generator/src/printer.js

@@ -332,9 +332,11 @@ export default class Printer {
     this._maybeAddAuxComment(this._insideAux && !oldInAux);
 
     let needsParens = n.needsParens(node, parent, this._printStack);
-    if (this.format.retainFunctionParens &&
-        node.type === "FunctionExpression" &&
-        node.extra && node.extra.parenthesized) {
+    if (
+      this.format.retainFunctionParens &&
+      node.type === "FunctionExpression" &&
+      node.extra && node.extra.parenthesized
+    ) {
       needsParens = true;
     }
     if (needsParens) this.token("(");

packages/babel-plugin-transform-object-rest-spread/README.md

@@ -4,19 +4,22 @@
 
 ## Example
 
+### Rest Properties
+
 ```js
-// Rest properties
 let { x, y, ...z } = { x: 1, y: 2, a: 3, b: 4 };
 console.log(x); // 1
 console.log(y); // 2
 console.log(z); // { a: 3, b: 4 }
+```
 
-// Spread properties
+### Spread Properties
+
+```js
 let n = { x, y, ...z };
 console.log(n); // { x: 1, y: 2, a: 3, b: 4 }
 ```
 
-
 ## Installation
 
 ```sh
@@ -35,27 +38,6 @@ npm install --save-dev babel-plugin-transform-object-rest-spread
 }
 ```
 
-## Options
-
-This plugin will use babel's `extends` helper, which will polyfill `Object.assign` by default.
-
-* `useBuiltIns` - Do not use Babel's helper's and just transform to use the built-in method (Disabled by default).
-
-```json
-{
-  "plugins": [
-    ["transform-object-rest-spread", { "useBuiltIns": true }]
-  ]
-}
-```
-
-```js
-// source
-z = { x, ...y };
-// compiled
-z = Object.assign({ x }, y);
-```
-
 ### Via CLI
 
 ```sh
@@ -70,6 +52,36 @@ require("babel-core").transform("code", {
 });
 ```
 
+## Options
+
+### `useBuiltIns`
+
+`boolean`, defaults to `false`.
+
+By default, this plugin uses Babel's `extends` helper which polyfills `Object.assign`. Enabling this option will use `Object.assign` directly.
+
+**.babelrc**
+
+```json
+{
+  "plugins": [
+    ["transform-object-rest-spread", { "useBuiltIns": true }]
+  ]
+}
+```
+
+**In**
+
+```js
+z = { x, ...y };
+```
+
+**Out**
+
+```js
+z = Object.assign({ x }, y);
+```
+
 ## References
 
 * [Proposal: Object Rest/Spread Properties for ECMAScript](https://github.com/sebmarkbage/ecmascript-rest-spread)