Add feature to disable component

lib/compiler.js

@@ -480,7 +480,9 @@ function resolveMiddlewareParams(rootDir, params) {
 }
 
 function buildComponentInstructions(rootDir, componentConfig) {
-  return Object.keys(componentConfig).map(function(name) {
+  return Object.keys(componentConfig)
+    .filter(function(name) { return !!componentConfig[name]; })
+    .map(function(name) {
       var sourceFile;
       if (name.indexOf('./') === 0 || name.indexOf('../') === 0) {
         // Relative path

test/executor.test.js

@@ -468,9 +468,27 @@ describe('executor', function() {
 
     boot(app, appdir.PATH);
 
+    expect(Object.keys(require.cache)).to.include(
+      appdir.resolve('components/test-component/index.js'));
+
     expect(app.componentOptions).to.eql({ option: 'value' });
   });
 
+  it('disables component when configuration is not set', function() {
+    appdir.writeConfigFileSync('component-config.json', {
+      './components/test-component': false
+    });
+
+    appdir.writeFileSync('components/test-component/index.js',
+      'module.exports = ' +
+      'function(app, options) { app.componentOptions = options; }');
+
+    boot(app, appdir.PATH);
+
+    expect(Object.keys(require.cache)).to.not.include(
+      appdir.resolve('components/test-component/index.js'));
+  });
+
   it('configures middleware (that requires `this`)', function(done) {
     var passportPath = require.resolve('./fixtures/passport');