added instanceof and primitive to check API

README.md

@@ -103,6 +103,7 @@ Inspired by chaijs, the assertion supports chainable `.is` and `.not` getters to
 
     it.is.typeof('string'); // typeof operator
     it.is.kindof('array'); // same as typeof but distinguises null and array
+    it.is.instanceof(String);
 
     it.equals(123); // ===
     it.is.gt(Infinity); // >
@@ -115,6 +116,7 @@ Inspired by chaijs, the assertion supports chainable `.is` and `.not` getters to
     it.is.defined; // !== undefined
     it.is.null; // === null
     it.is.value; // != null
+    it.is.primitive; // null|undefined|String|Boolean|Number
 
     // NOTE: negate the assertion using `.not` before the endpoint.
     // NOTE: `.is` is merely aesthetic, and can be safely omitted.
@@ -145,3 +147,4 @@ Please submit any issues or feature requests to the repository's github [issue t
 
 ## Version History
   - v0.1.0 - Initial release
+  - v0.2.0 - Added `instanceof` and `.primitive` to check API

package.json

@@ -13,7 +13,7 @@
     "gulp-rimraf": "~0.2.0"
   },
   "name": "ok-js",
-  "version": "0.1.0",
+  "version": "0.2.0",
   "description": "An object utility library",
   "main": "index.js",
   "directories": {

src/check.js

@@ -58,6 +58,10 @@ Assertion.prototype = {
     return utils.kindof(this._data) === type;
   },
 
+  instanceof: function (Klass) {
+    return this._data instanceof Klass;
+  },
+
   lt: function (v) {
     return this._data < v;
   },
@@ -119,6 +123,20 @@ Object.defineProperty(Assertion.prototype, 'value', {
   }
 });
 
+Object.defineProperty(Assertion.prototype, 'primitive', {
+  get: function () {
+    var result;
+
+    if (!utils.isValue(this._data)) {
+      return !this._negate;
+    }
+
+    result = this.typeof('string') || this.typeof('number') || this.typeof('boolean');
+
+    return this._negate ? !result : result;
+  }
+});
+
 module.exports = function (context, property) {
   var value;