Jasmine toDeepPartiallyEqual custom matcher

matchers.js

'use strict';

var customMatchers = {
    toDeepPartiallyEqual: function (expected) {
        var compare = function(obj1, obj2) {
            for(var i in obj2) {
                if(typeof obj2[i] !== typeof obj1[i]) {
                    return false
                }
                switch (typeof obj2[i]) {
                    case 'undefined':
                        return false;
                    case 'object':
                        if(!compare(obj1[i], obj2[i])) {
                            return false;
                        }
                        break;
                    default:
                        if(obj1[i] !== obj2[i]) {
                            return false;
                        }
                }
            }
            return true;
        };
        var notText = this.isNot ? "not" : "";
        this.message = function () {
            return "Deep partially equal: \n\t" + JSON.stringify(this.actual) + "\nis " + notText + " equal to\n\t" + JSON.stringify(expected)
        };
        return compare(this.actual, expected)
    }
};

ddescribe("Deep partially equal", function() {

    beforeEach(function() {
        this.addMatchers(customMatchers);
        // https://api.github.com/gists/public
        this.a = [
            {
                "url": "https://api.github.com/gists/1105b4801915a5b07139",
                "forks_url": "https://api.github.com/gists/1105b4801915a5b07139/forks",
                "commits_url": "https://api.github.com/gists/1105b4801915a5b07139/commits",
                "id": "1105b4801915a5b07139",
                "git_pull_url": "https://gist.github.com/1105b4801915a5b07139.git",
                "git_push_url": "https://gist.github.com/1105b4801915a5b07139.git",
                "html_url": "https://gist.github.com/1105b4801915a5b07139",
                "files": {
                    "gistfile1.sh": {
                        "filename": "gistfile1.sh",
                        "type": "application/x-sh",
                        "language": [
                            {
                                "type": "Shell"
                            },
                            {
                                "type": "C"
                            }
                        ],
                        "size": 329
                    }
                }
            }
        ];
    });

    it("should exactly equal JSON", function() {
        expect(this.a).toDeepPartiallyEqual(this.a);
    });

    it("should deep partially equal JSON", function() {
        var b = [
            {
                "files": {
                    "gistfile1.sh": {
                        "type": "application/x-sh",
                        "language": [
                            {
                                "type": "Shell"
                            },
                            {
                                "type": "C"
                            }
                        ],
                        "size": 329
                    }
                }
            }
        ];
        expect(this.a).toDeepPartiallyEqual(b);
    });

    it("should not deep partially equal JSON", function() {
        var b = [
            {
                "files": {
                    "gistfile1.sh": {
                        "language": [
                            {
                                "type": "Shelll"
                            }
                        ]
                    }
                }
            }
        ];
        expect(this.a).not.toDeepPartiallyEqual(b);
    });
});