Optional babel transpilation

README.md

@@ -38,6 +38,21 @@ As of version 0.4, **injectr** doesn't create a full node.js context for you to
 use. Instead, it isolates your script in its own sandbox, allowing you to
 include mocks of only the bits that your script needs.
 
+## Configure for Babel ##
+
+Injectr optionally transpiles babel for `.js` and `.jsx` files.  Injectr
+automatically reads in `.injectrrc` in the root of your project.  For example,
+to enable babel transpilation within injectr, simply add `.injectrrc`:
+
+```json
+{
+  "babel": true,
+  "babelOptions": {}
+}
+```
+
+You will need to `npm install --save-dev babel-core` for this to work.
+
 ### CoffeeScript ###
 
 **injectr** compiles any *.coffee files for you, so you can test your

lib/injectr.js

@@ -3,15 +3,38 @@
 var cache = {},
     fs = require('fs'),
     path = require('path'),
-    vm = require('vm');
+    vm = require('vm'),
+    encoding = 'utf8',
+    OPTION_FILE_NAME = '.injectrrc',
+    injectrRC,
+    options = { babel: null, babelOptions: null };
+
+/**
+ * Parse options from .injectrrc if present.
+ * Injectrrc is expected to be a JSON file.
+ */
+(function _parseOptions() {
+  try {
+      injectrRC = fs.readFileSync(
+        process.env.PWD + '/' + OPTION_FILE_NAME,
+        encoding
+      );
+
+      try {
+          options = JSON.parse(injectrRC);
+      } catch (e) {
+          console.error('ERR: Unable to parse .injectrrc file');
+      }
+  } catch (e) {}
+})();
 
 module.exports = function (file, mocks, context) {
     var script;
     mocks = mocks || {};
     context = context || {};
     file = path.join(path.dirname(module.parent.filename), file);
     cache[file] = cache[file] || module.exports.onload(file,
-        fs.readFileSync(file, 'utf8'));
+        fs.readFileSync(file, encoding));
     script = vm.createScript(cache[file], file);
     context.require = function (a) {
         if (mocks[a]) {
@@ -35,6 +58,11 @@ module.exports.onload = function (file, content) {
         return require('coffee-script').compile(content, {
             filename : file
         });
+    } else if (options.babel && file.match(/\.js(x)?$/)) {
+        return require('babel-core').transform(
+          content,
+          options.babelOptions || {}
+        ).code;
     }
     return content;
 };