Fix yeoman-generator ignoring errors

Author: SBoudrias

lib/base.js

@@ -423,29 +423,22 @@ Base.prototype.run = function run(cb) {
       debug('Running ' + methodName);
       self.emit('method:' + methodName);
 
-      runAsync(
-        function () {
-          self.async = function () {
-            return this.async();
-          }.bind(this);
-
-          return method.apply(self, self.args);
-        },
-        // runAsync return a promise which wraps first function.
-        // So ensure the callback function never throw an error.
-        function (err) {
-          if (err) {
-            debug('An error occured while running ' + methodName, err);
-            if (self.listeners('error').length > 0) {
-              self.emit('error', err);
-            }
-            cb(err);
-            return;
-          }
-
-          completed();
-        }
-      )();
+      runAsync(function () {
+        self.async = function () {
+          return this.async();
+        }.bind(this);
+
+        return method.apply(self, self.args);
+      })().then(completed).catch(function (err) {
+        debug('An error occured while running ' + methodName, err);
+
+        // Ensure we emit the error event outside the promise context so it won't be
+        // swallowed when there's no listeners.
+        setImmediate(function () {
+          self.emit('error', err);
+          cb(err);
+        });
+      });
     });
   }
 

test/base.js

@@ -319,23 +319,7 @@ describe('generators.Base', function () {
       this.testGen.on('error', sinon.spy());
       this.testGen.run(function (err) {
         assert.equal(err, error);
-        sinon.assert.notCalled(spy);
-        done();
-      });
-    });
-
-    it('stop queue processing once an error is thrown and "error" event has no listeners', function (done) {
-      var error = new Error();
-      var spy = sinon.spy();
-
-      this.TestGenerator.prototype.throwing = function () {
-        throw error;
-      };
-      this.TestGenerator.prototype.afterError = spy;
-
-      this.testGen.run(function (err) {
-        assert.equal(err, error);
-        sinon.assert.notCalled(spy);
+        sinon.assert.called(spy);
         done();
       });
     });