Add support to don't schedule generator queue at composeWith.

lib/environment.js

@@ -812,14 +812,23 @@ class Environment extends Base {
    * @param {String} namespaceOrPath
    * @param {Array} [args]
    * @param {Object} [options]
+   * @param {Boolean} [schedule]
    * @return {Generator} The instantiated generator or the singleton instance.
    */
-  composeWith(generator, args, options) {
+  composeWith(generator, args, options, schedule = true) {
+    if (typeof args === 'boolean') {
+      schedule = args;
+      args = undefined;
+      options = undefined;
+    } else if (typeof options === 'boolean') {
+      schedule = options;
+      options = undefined;
+    }
     const generatorInstance = this.create(generator, args, options);
     if (generatorInstance.then) {
-      return generatorInstance.then(generatorInstance => this.queueGenerator(generatorInstance, true));
+      return generatorInstance.then(generatorInstance => this.queueGenerator(generatorInstance, schedule));
     }
-    return this.queueGenerator(generatorInstance, true);
+    return this.queueGenerator(generatorInstance, schedule);
   }
 
   /**

test/environment.js

@@ -235,6 +235,21 @@ describe('Environment', () => {
       assert.ok(this.env.composeWith('stub') instanceof this.Generator);
     });
 
+    it('should schedule generator queue', function () {
+      this.env.runLoop.add = sinon.spy();
+      this.env.composeWith('stub');
+      assert(this.env.runLoop.add.calledOnce);
+      assert(this.env.runLoop.add.getCall(0).firstArg === 'environment:run');
+    });
+
+    describe('passing false schedule parameter', () => {
+      it('should queue generator tasks', function () {
+        this.env.runLoop.add = sinon.spy();
+        this.env.composeWith('stub', [], {}, false);
+        assert(this.env.runLoop.add.getCall(0).firstArg !== 'environment:run');
+      });
+    });
+
     it('should emit a compose event', function (done) {
       this.env.once('compose', (namespace, generator) => {
         assert.ok(namespace === 'stub');