common: fix linting failures

stephenplusplus · stephenplusplus · commit 6e11db17fa0a · 2017-03-28T14:35:24.000-04:00
diff --git a/packages/common/src/util.js b/packages/common/src/util.js
@@ -706,17 +706,25 @@ function promisify(originalMethod, options) {
   var slice = Array.prototype.slice;
 
   var wrapper = function() {
+    var context = this;
     var last;
+
     for (last = arguments.length - 1; last >= 0; last--) {
       var arg = arguments[last];
-      if (arg === undefined) continue;  // skip trailing undefined.
-      if (!is.fn(arg)) break;           // non-callback last argument found.
-      return originalMethod.apply(this, arguments);
+
+      if (is.undefined(arg)) {
+        continue; // skip trailing undefined.
+      }
+
+      if (!is.fn(arg)) {
+        break; // non-callback last argument found.
+      }
+
+      return originalMethod.apply(context, arguments);
     }
 
     // peel trailing undefined.
     var args = slice.call(arguments, 0, last + 1);
-    var context = this;
 
     var PromiseCtor = Promise;
 
diff --git a/packages/common/test/util.js b/packages/common/test/util.js
@@ -1648,32 +1648,6 @@ describe('common/util', function() {
 
       assert.strictEqual(FakeClass.prototype.methodName, method);
     });
-
-    describe('trailing undefined arguments', function() {
-      it('should not return a promise in callback mode', function(done) {
-        var func = util.promisify(function(optional, callback) {
-          assert(is.fn(optional));
-          optional(null);
-        });
-
-        var returnVal = func(function() {
-          assert(!returnVal);
-          done();
-        });
-      });
-
-      it('should return a promise when callback omitted', function(done) {
-        var func = util.promisify(function(optional, callback) {
-          assert.strictEqual(arguments.length, 1);
-          assert(is.fn(optional));
-          optional(null);
-        });
-
-        var returnVal = func(undefined, undefined).then(function() {
-          done();
-        });
-      });
-    });
   });
 
   describe('promisify', function() {
@@ -1760,5 +1734,31 @@ describe('common/util', function() {
         assert.deepEqual(args, fakeArgs);
       });
     });
+
+    describe('trailing undefined arguments', function() {
+      it('should not return a promise in callback mode', function(done) {
+        var func = util.promisify(function(optional) {
+          assert(is.fn(optional));
+          optional(null);
+        });
+
+        var returnVal = func(function() {
+          assert(!returnVal);
+          done();
+        });
+      });
+
+      it('should return a promise when callback omitted', function(done) {
+        var func = util.promisify(function(optional) {
+          assert.strictEqual(arguments.length, 1);
+          assert(is.fn(optional));
+          optional(null);
+        });
+
+        func(undefined, undefined).then(function() {
+          done();
+        });
+      });
+    });
   });
 });
