jasmine object introspection matcher

hasPropertiesMatcher.js

beforeEach(function() {
  	this.addMatchers({

			//
			// ### function hasProperties expected
			// #### @expected Array of Object or single Object with expected key value pairs.
			// Custom matcher to verify that the actual object under test contains given
			// properties with corresponding values.
			// 
			// The matcher will fail if either the property does not exist, or the values do not match.
			// 
			// Expected objects must contain `name` and `equals`;
			// 
			// Usage:
			// expect(myObject).hasProperties([
			// 	{name: 'id', equals: 'movideo'}
			// ]);
			// 
			hasProperties: function(expected) {

				this.message = function () {
					return msg;
				}

				var actual = this.actual;
				var inst = typeof actual;
				var msg = 'Expected ' + inst + ' to have ';

				var notText = this.isNot ? " not" : "";

				// convert to array if not already
				if (Object.prototype.toString.call(expected) !== '[object Array]') {
					expected = [expected];
				}

				var failure = expected.some(function(matcher) {
						
					var propName = matcher.name;
					var propVal = matcher.equals;

					if (!actual.hasOwnProperty(propName)) {
						msg += 'property ' + "'" + propName + "'" + ' but was not found.';
						
						// this means shortcut
						return true;
					}
					
					var actualVal = actual[propName];
					if (actualVal !== propVal) {
						msg += 'property ' + "'" + propName + "'" + ' with value ' + "'" + propVal + "'";
						msg += ' but was ' + "'" + actualVal + "'";
						
						// this means shortcut
						return true;
					}
				})

				// return inverse of the some() operation, since it shortcuts on a failure
				return !failure;
			}
		})
	})