Fixes #57 Allow requiring non-JS dependencies to work on the server

README.md

@@ -484,17 +484,34 @@ Lasso.js walks a dependency graph to find all of the resources that need to be b
 
 It's also possible to register your own [custom dependency types](#custom-dependency-types). With custom dependency types, you can control how resources are compiled or a custom dependency type can be used to resolve additional dependencies during optimization.
 
-A dependency can be described using a simple `String` path as shown in the following code:
+A dependency can be described using a simple `String` path as shown in the following sample `browser.json` file:
 
 ```json
-[
-    "./style.less",
-    "../third-party/jquery.js",
-    "**/*.css"
-]
+{
+	"dependencies": [
+	    "./style.less",
+	    "../third-party/jquery.js",
+	    "**/*.css"
+	]
+}
 ```
 
-In the examples, the dependency type is inferred from the filename extension. Alternatively, the dependency type can be made explicit using either one of the following formats:
+Alternatively, dependencies can be "required" inside a JavaScript module as shown in the following sample JavaScript code:
+
+```javascript
+require('./style.less');
+
+// ...
+```
+
+The only caveat to using a `require()` call to add a non-JavaScript module dependency is that by default Node.js will try to load the required file as a JavaScript module if the code runs on the server. To prevent Node.js from trying to load a Less file or other non-JavaScript files as JavaScript modules you can add the following code to your main script:
+
+```javascript
+require('lasso/node-require-no-op').enable('.less', '.css');
+```
+
+
+For simple paths, the dependency type is inferred from the filename extension. Alternatively, the dependency type can be made explicit using either one of the following formats:
 
 ```json
 [

node-require-no-op.js

@@ -0,0 +1,28 @@
+function requireNoOp(module, filename) { /* no-op */ }
+
+function enableForExtension(extension) {
+    if (extension == null) {
+        return;
+    }
+
+    if (Array.isArray(extension)) {
+        extension.forEach(enableForExtension);
+        return;
+    }
+
+    if (typeof extension !== 'string') {
+        throw new Error('Expected extension to be a string. Actual: ' + extension);
+    }
+
+    if (extension.charAt(0) !== '.') {
+        extension = '.' + extension;
+    }
+
+    require.extensions[extension] = requireNoOp;
+}
+
+exports.enable = function(extensions) {
+    for (var i=0; i<arguments.length; i++) {
+        enableForExtension(arguments[i]);
+    }
+};

test/require-no-op-test.js

@@ -0,0 +1,19 @@
+'use strict';
+var chai = require('chai');
+chai.Assertion.includeStack = true;
+var expect = chai.expect;
+
+describe('node-require-no-op', function() {
+
+    it('should allow for optimizing a page with flags', function() {
+        require('../node-require-no-op').enable('.xfoo');
+        require('../node-require-no-op').enable('xbar');
+        require('../node-require-no-op').enable(['yfoo', '.ybar']);
+
+        var test = require('./fixtures/noop/test.xfoo');
+        expect(Object.keys(test).length).to.equal(0);
+        require('./fixtures/noop/test.xbar');
+        require('./fixtures/noop/test.yfoo');
+        require('./fixtures/noop/test.yfoo');
+    });
+});