Add extractSourceLocation option

This option will provide metadata in the Message Description for the
file and location in the file where the message was defined. When
enabled and running it on [this file][1] you'll get this result:

```json
[
  {
    "id": "app.title",
    "defaultMessage": "React Intl Translations Example",
    "file": "src/client/components/app.js",
    "start": {
      "line": 23,
      "column": 20
    },
    "end": {
      "line": 26,
      "column": 22
    }
  },
  {
    "id": "app.locales_menu_heading",
    "defaultMessage": "Locales:",
    "file": "src/client/components/app.js",
    "start": {
      "line": 32,
      "column": 20
    },
    "end": {
      "line": 35,
      "column": 22
    }
  }
]
```

Fixes #71

[1]: https://github.com/yahoo/react-intl/blob/25f3f64d86ac86281157117b5bdb9fa30d1d615f/examples/translations/src/client/components/app.js

Author: ericf

README.md

@@ -24,8 +24,7 @@ The default message descriptors for the app's default language will be extracted
 {
   "plugins": [
     ["react-intl", {
-        "messagesDir": "./build/messages/",
-        "enforceDescriptions": true
+        "messagesDir": "./build/messages/"
     }]
   ]
 }
@@ -35,7 +34,9 @@ The default message descriptors for the app's default language will be extracted
 
 - **`messagesDir`**: The target location where the plugin will output a `.json` file corresponding to each component from which React Intl messages were extracted. If not provided, the extracted message descriptors will only be accessible via Babel's API.
 
-- **`enforceDescriptions`**: Whether or not message declarations _must_ contain a `description` to provide context to translators. Defaults to: `false`.
+- **`enforceDescriptions`**: Whether message declarations _must_ contain a `description` to provide context to translators. Defaults to: `false`.
+
+- **`extractSourceLocation`**: Whether the metadata about the location of the message in the source file should be extracted. If `true`, then `file`, `start`, and `end` fields will exist for each extracted message descriptors. Defaults to `false`.
 
 - **`moduleSourceName`**: The ES6 module source name of the React Intl package. Defaults to: `"react-intl"`, but can be changed to another name/path to React Intl.
 

scripts/build-fixtures.js

@@ -7,6 +7,9 @@ const baseDir = p.resolve(`${__dirname}/../test/fixtures`);
 
 const fixtures = [
     'defineMessages',
+    ['extractSourceLocation', {
+        extractSourceLocation: true,
+    }],
     'FormattedHTMLMessage',
     'FormattedMessage',
     ['moduleSourceName', {

src/index.js

@@ -107,7 +107,7 @@ export default function () {
     }
 
     function storeMessage({id, description, defaultMessage}, path, state) {
-        const {opts, reactIntl} = state;
+        const {file, opts, reactIntl} = state;
 
         if (!(id && defaultMessage)) {
             throw path.buildCodeFrameError(
@@ -134,7 +134,15 @@ export default function () {
             );
         }
 
-        reactIntl.messages.set(id, {id, description, defaultMessage});
+        let loc;
+        if (opts.extractSourceLocation) {
+            loc = {
+                file: p.relative(process.cwd(), file.opts.filename),
+                ...path.node.loc,
+            };
+        }
+
+        reactIntl.messages.set(id, {id, description, defaultMessage, ...loc});
     }
 
     function referencesImport(path, mod, importedNames) {
@@ -257,7 +265,7 @@ export default function () {
 
                     // Evaluate the Message Descriptor values, then store it.
                     descriptor = evaluateMessageDescriptor(descriptor);
-                    storeMessage(descriptor, path, state);
+                    storeMessage(descriptor, messageObj, state);
                 }
 
                 if (referencesImport(callee, moduleSourceName, FUNCTION_NAMES)) {

test/fixtures/extractSourceLocation/actual.js

@@ -0,0 +1,13 @@
+import React, {Component} from 'react';
+import {FormattedMessage} from 'react-intl';
+
+export default class Foo extends Component {
+    render() {
+        return (
+            <FormattedMessage
+                id='foo.bar.baz'
+                defaultMessage='Hello World!'
+            />
+        );
+    }
+}

test/fixtures/extractSourceLocation/expected.js

@@ -0,0 +1,45 @@
+'use strict';
+
+Object.defineProperty(exports, "__esModule", {
+    value: true
+});
+
+var _createClass = function () { function defineProperties(target, props) { for (var i = 0; i < props.length; i++) { var descriptor = props[i]; descriptor.enumerable = descriptor.enumerable || false; descriptor.configurable = true; if ("value" in descriptor) descriptor.writable = true; Object.defineProperty(target, descriptor.key, descriptor); } } return function (Constructor, protoProps, staticProps) { if (protoProps) defineProperties(Constructor.prototype, protoProps); if (staticProps) defineProperties(Constructor, staticProps); return Constructor; }; }();
+
+var _react = require('react');
+
+var _react2 = _interopRequireDefault(_react);
+
+var _reactIntl = require('react-intl');
+
+function _interopRequireDefault(obj) { return obj && obj.__esModule ? obj : { default: obj }; }
+
+function _classCallCheck(instance, Constructor) { if (!(instance instanceof Constructor)) { throw new TypeError("Cannot call a class as a function"); } }
+
+function _possibleConstructorReturn(self, call) { if (!self) { throw new ReferenceError("this hasn't been initialised - super() hasn't been called"); } return call && (typeof call === "object" || typeof call === "function") ? call : self; }
+
+function _inherits(subClass, superClass) { if (typeof superClass !== "function" && superClass !== null) { throw new TypeError("Super expression must either be null or a function, not " + typeof superClass); } subClass.prototype = Object.create(superClass && superClass.prototype, { constructor: { value: subClass, enumerable: false, writable: true, configurable: true } }); if (superClass) Object.setPrototypeOf ? Object.setPrototypeOf(subClass, superClass) : subClass.__proto__ = superClass; }
+
+var Foo = function (_Component) {
+    _inherits(Foo, _Component);
+
+    function Foo() {
+        _classCallCheck(this, Foo);
+
+        return _possibleConstructorReturn(this, (Foo.__proto__ || Object.getPrototypeOf(Foo)).apply(this, arguments));
+    }
+
+    _createClass(Foo, [{
+        key: 'render',
+        value: function render() {
+            return _react2.default.createElement(_reactIntl.FormattedMessage, {
+                id: 'foo.bar.baz',
+                defaultMessage: 'Hello World!'
+            });
+        }
+    }]);
+
+    return Foo;
+}(_react.Component);
+
+exports.default = Foo;

test/fixtures/extractSourceLocation/expected.json

@@ -0,0 +1,15 @@
+[
+  {
+    "id": "foo.bar.baz",
+    "defaultMessage": "Hello World!",
+    "file": "test/fixtures/extractSourceLocation/actual.js",
+    "start": {
+      "line": 7,
+      "column": 12
+    },
+    "end": {
+      "line": 10,
+      "column": 14
+    }
+  }
+]

test/index.js

@@ -12,6 +12,7 @@ const skipTests = [
     '.babelrc',
     '.DS_Store',
     'enforceDescriptions',
+    'extractSourceLocation',
     'moduleSourceName',
     'icuSyntax',
 ];
@@ -49,7 +50,9 @@ describe('options', () => {
         const fixtureDir = path.join(fixturesDir, 'enforceDescriptions');
 
         try {
-            transform(path.join(fixtureDir, 'actual.js'));
+            transform(path.join(fixtureDir, 'actual.js'), {
+                enforceDescriptions: true,
+            });
             assert(false);
         } catch (e) {
             assert(e);
@@ -83,6 +86,30 @@ describe('options', () => {
             console.error(e);
             assert(false);
         }
+
+        // Check message output
+        const expectedMessages = fs.readFileSync(path.join(fixtureDir, 'expected.json'));
+        const actualMessages = fs.readFileSync(path.join(fixtureDir, 'actual.json'));
+        assert.equal(trim(actualMessages), trim(expectedMessages));
+    });
+
+    it('respects extractSourceLocation', () => {
+        const fixtureDir = path.join(fixturesDir, 'extractSourceLocation');
+
+        try {
+            transform(path.join(fixtureDir, 'actual.js'), {
+                extractSourceLocation: true,
+            });
+            assert(true);
+        } catch (e) {
+            console.error(e);
+            assert(false);
+        }
+
+        // Check message output
+        const expectedMessages = fs.readFileSync(path.join(fixtureDir, 'expected.json'));
+        const actualMessages = fs.readFileSync(path.join(fixtureDir, 'actual.json'));
+        assert.equal(trim(actualMessages), trim(expectedMessages));
     });
 });
 
@@ -99,13 +126,11 @@ describe('errors', () => {
             assert(/Expected .* but "\." found/.test(e.message));
         }
     });
-
 });
 
 
 const BASE_OPTIONS = {
     messagesDir: baseDir,
-    enforceDescriptions: true,
 };
 
 function transform(filePath, options = {}) {