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