Merge pull request #1761 from chromakode/explicit-null-and-defined

Explicitly check `null` and `undefined` values in exports.type
mochajs · Jul 4, 2015 · fc3fee6 · fc3fee6
2 parents c27110b + 0d16e02
commit fc3fee6
Show file tree

Hide file tree

Showing 2 changed files with 26 additions and 1 deletion.
diff --git a/lib/utils.js b/lib/utils.js
@@ -382,7 +382,11 @@ function emptyRepresentation(value, type) {
  * type(global) // 'global'
  */
 exports.type = function type(value) {
-  if (typeof Buffer !== 'undefined' && Buffer.isBuffer(value)) {
+  if (value === undefined) {
+    return 'undefined';
+  } else if (value === null) {
+    return 'null';
+  } else if (typeof Buffer !== 'undefined' && Buffer.isBuffer(value)) {
     return 'buffer';
   }
   return Object.prototype.toString.call(value)

diff --git a/test/acceptance/utils.js b/test/acceptance/utils.js
@@ -341,12 +341,33 @@ describe('lib/utils', function () {
       type(1).should.equal('number');
       type(Infinity).should.equal('number');
       type(null).should.equal('null');
+      type(undefined).should.equal('undefined');
       type(new Date()).should.equal('date');
       type(/foo/).should.equal('regexp');
       type('type').should.equal('string');
       type(global).should.equal('global');
       type(true).should.equal('boolean');
     });
+
+    describe('when toString on null or undefined stringifies window', function () {
+      var toString = Object.prototype.toString;
+
+      beforeEach(function () {
+        // some JS engines such as PhantomJS 1.x exhibit this behavior
+        Object.prototype.toString = function () {
+          return '[object DOMWindow]';
+        };
+      });
+
+      it('should recognize null and undefined', function () {
+        type(null).should.equal('null');
+        type(undefined).should.equal('undefined');
+      });
+
+      afterEach(function () {
+        Object.prototype.toString = toString;
+      });
+    });
   });
 
   describe('lookupFiles', function () {