Editing super-implementations

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Preparation code

Preparation code HTML (this will be inserted in the <body> of a valid HTML5 document in standards mode) (useful when testing DOM operations or including libraries)

Include JavaScript libraries as follows: <script src="//cdn.ext/library.js"></script>

Define setup for all tests (variables, functions, arrays or other objects that will be used in the tests) (runs before each clocked test loop, outside of the timed code region) (e.g. define local test variables, reset global variables, clear canvas, etc.) (see FAQ)

var F = function () {};

function createClass (name, superclass, callback) {
    var theClass;
    
    // create the function constructor for the class
    theClass = function () {
        // verify class is always instantiated with 'new' keyword
        if (!(this instanceof theClass)) {
            throw new Error('[' + name + '] Please use "new" keyword to instantiate class');
        }
        this.init.apply(this, arguments);
    };

// Setup display name and superclass
    theClass.displayName = theClass._name = name;

// store class in window
    window[name] = theClass;

// inherit from the superclass unless we're processing the base class
    if (superclass) {
        F.prototype = superclass.prototype;
        theClass.superclass = superclass;
        theClass.prototype = new F();
        theClass.prototype.constructor = theClass;
    }
    superclass = theClass.superclass ? theClass.superclass.prototype : {};
    
    // invoke callback to "implement" class and process it afterwards 
    callback(theClass);
    
    // process instance (prototype) methods of the class
    for (var method in theClass.prototype) {
        if (!theClass.prototype.hasOwnProperty(method)) {
            return;
        }
        processMethod(theClass, method);
        
        // if method uses .callSuper, use a closure to keep reference of the corresponding superclass' method
        if ((typeof superclass[method] === 'function') && /this\.callSuper3\(/.test(theClass.prototype[method])) {
            theClass.prototype[method] = overrideCallSuper(theClass.prototype[method], superclass[method]);
        }
    }
    
}

function processMethod (theClass, methodName) {
    var parent = theClass.prototype;
    var prop = Object.getOwnPropertyDescriptor(parent, methodName).value;

// only process functions
    if (typeof prop !== 'function') {
        return;
    }

prop._class = theClass;
    prop._name = methodName;

if (!prop.displayName) {
        prop.displayName = theClass.displayName + '#' + methodName + '()';
    }
}

function overrideCallSuper (method, superMethod) {
    return function () {
        // locally store existing callSuper to avoid overwriting it if it already exists
        var callSuper = this.callSuper3;
        var results;

// override the callSuper method with the actual's superclass method
        // and call the actual method
        this.callSuper3 = superMethod;
        results = method.apply(this, arguments);
        // restore callSuper and return results
        this.callSuper3 = callSuper;
        return results;
    };
}

createClass('Person', null, function () {
    
    Person.prototype.init = function (firstName, lastName) {
        this.firstName = firstName;
        this.lastName = lastName;
    };
    
    Person.prototype.name = function (msg) {
        return '1. ' + this.firstName + ' ' + this.lastName;
    };

Person.prototype.name2 = function (msg) {
        return '2. ' + this.firstName + ' ' + this.lastName;
    };
    
    Person.prototype.name3 = function (msg) {
        return '3. ' + this.firstName + ' ' + this.lastName;
    };

Person.prototype.callSuper = function () {
        // figure out what function called us
        var caller = Person.prototype.callSuper.caller;
        var parent = caller._class.superclass.prototype;
        var method_name = caller._name;
        return parent[method_name].apply(this, arguments);
    };

Person.prototype.callSuper2 = function (methodName) {
         var args = Array.prototype.slice.call(arguments); 
         return this.constructor.superclass.prototype[methodName].apply(this, args.slice(1));
     };
});

createClass('Employee', Person, function () {
    
    Employee.prototype.init = function (firstName, lastName, title) {
        this.firstName = firstName;
        this.lastName = lastName;
        this.title = title;
    };
    
    Employee.prototype.name = function (msg) {
        return this.callSuper() + ' (Employed)';
    };

Employee.prototype.name2 = function (msg) {
        return this.callSuper2('name2') + ' (Employed)';
    };
    
    Employee.prototype.name3 = function (msg) {
        return this.callSuper3() + ' (Employed)';
    };
});

var john = new Employee('John', 'Smith', 'Assistant');

Define teardown for all tests (runs after each clocked test loop, outside of the timed code region) (see FAQ)

Code snippets to compare

Test 1

Title

Async (check if this is an asynchronous test)

Code

john.name();

Test 2

Title

Async (check if this is an asynchronous test)

Code

john.name2();

Test 3

Title

Async (check if this is an asynchronous test)

Code

john.name3();