New: Add isVinyl function

Author: yocontra

README.md

@@ -34,15 +34,24 @@ var coffeeFile = new File({
 });
 ```
 
-### constructor(options)
+### isVinyl
+When checking if an object is a vinyl file, you should not use instanceof. Use the isVinyl function instead.
 
-#### options.cwd
+```js
+var File = require('vinyl');
 
-Type: `String`<br>
-Default: `process.cwd()`
+var dummy = new File({stuff});
+var notAFile = {};
 
-#### options.base
+File.isVinyl(dummy); // true
+File.isVinyl(notAFile); // false
+```
 
+### constructor(options)
+#### options.cwd
+Type: `String`<br><br>Default: `process.cwd()`
+
+#### options.base
 Used for relative pathing. Typically where a glob starts.
 
 Type: `String`<br>

index.js

@@ -16,16 +16,16 @@ function File(file) {
   var history = file.path ? [file.path] : file.history;
   this.history = history || [];
 
-  // TODO: should this be moved to vinyl-fs?
   this.cwd = file.cwd || process.cwd();
   this.base = file.base || this.cwd;
 
-  // stat = fs stats object
-  // TODO: should this be moved to vinyl-fs?
+  // stat = files stats object
   this.stat = file.stat || null;
 
   // contents = stream, buffer, or null if not read
   this.contents = file.contents || null;
+
+  this._isVinyl = true;
 }
 
 File.prototype.isBuffer = function() {
@@ -133,6 +133,10 @@ File.prototype.inspect = function() {
   return '<File '+inspect.join(' ')+'>';
 };
 
+File.isVinyl = function(file) {
+  return file && file._isVinyl === true;
+};
+
 // virtual attributes
 // or stuff with extra logic
 Object.defineProperty(File.prototype, 'contents', {

package.json

@@ -1,7 +1,7 @@
 {
   "name": "vinyl",
   "description": "A virtual file format",
-  "version": "0.5.1",
+  "version": "0.5.2",
   "homepage": "http://github.com/wearefractal/vinyl",
   "repository": "git://github.com/wearefractal/vinyl.git",
   "author": "Fractal <contact@wearefractal.com> (http://wearefractal.com/)",
@@ -24,7 +24,7 @@
     "lodash.templatesettings": "^3.1.0",
     "mocha": "^2.0.0",
     "rimraf": "^2.2.5",
-    "should": "^6.0.0"
+    "should": "^7.0.0"
   },
   "scripts": {
     "test": "mocha && jshint lib",

test/File.js

@@ -8,6 +8,21 @@ var should = require('should');
 require('mocha');
 
 describe('File', function() {
+  describe('isVinyl()', function() {
+    it('should return true on a vinyl object', function(done) {
+      var file = new File();
+      File.isVinyl(file).should.equal(true);
+      done();
+    });
+    it('should return false on a normal object', function(done) {
+      File.isVinyl({}).should.equal(false);
+      done();
+    });
+    it('should return false on a null object', function(done) {
+      File.isVinyl({}).should.equal(false);
+      done();
+    });
+  });
   describe('constructor()', function() {
     it('should default cwd to process.cwd', function(done) {
       var file = new File();