Clone object JS

clone.js

function clone(obj) {
    if (obj === null || typeof obj === 'undefined' || typeof obj !== 'object') return obj;
    cloned = {};
    for (key in obj) {
        if (Object.hasOwnProperty.call(obj, key)) {
            cloned[key] = clone(obj[key]);
        }
    }
    return cloned;
}

test.js

var nbError = 0;
var nbSuccess = 0;

function assert(message, bool) {
    if (bool === true) {
        nbSuccess++;
        console.log(message + ': OK');
    }
    else {
        nbError++;
        console.log(message + ': ASSERTION ERROR');
    }
}

function displayTestingResult() {
    console.log('There are ' + nbError + ' failed test.');
    console.log('There are ' + nbSuccess + ' successful test.');
}

function testingWithoutClone(obj) {
    var notClonedObj = obj;

    console.log('obj:', obj);
    console.log('notClonedObj:', notClonedObj);

    console.log('----------------------------------------------');

    assert('obj and notClonedObj should be equal to itself...', obj === notClonedObj);

    notClonedObj.unknownParam = 0.0;
    assert('Modify notClonedObj should modify obj', typeof obj.unknownParam === 'number');

    console.log('----------------------------------------------');

    console.log('obj:', obj);
    console.log('clonedObj:', notClonedObj);
}

function testingWithClone(obj) {
    var clonedObj = clone(obj);

    console.log('obj:', obj);
    console.log('clonedObj:', clonedObj);

    console.log('----------------------------------------------');

    assert('obj and clonedObj should not be equal to itself', obj !== clonedObj);
    clonedObj.unknownParam = 0.0;
    assert('Modify clonedObj should not modify obj', typeof obj.unknownParam === 'undefined');

    console.log('----------------------------------------------');

    console.log('obj:', obj);
    console.log('clonedObj:', clonedObj);
}

console.log('Testing basic object...');
console.log('===');
console.log('=== Without cloning');
console.log('===');
testingWithoutClone({param1: '1'});
console.log('===');
console.log('=== With cloning');
console.log('===');
testingWithClone({param1: '1'});
console.log();
console.log('========================================================================');
console.log();
console.log('Testing custom object (without functions)...');
var MyObjectWithoutFunction = function () {
    this.param1 = '1';
    this.param2 = 2;
};
console.log();
console.log('===');
console.log('=== Without cloning');
console.log('===');
console.log();
testingWithoutClone(new MyObjectWithoutFunction());
console.log();
console.log('===');
console.log('=== With cloning');
console.log('===');
console.log();
testingWithClone(new MyObjectWithoutFunction());
console.log();
console.log('========================================================================');
console.log();
console.log('Testing custom object (with functions)...');
var MyObjectWithFunction = function () {
    this.param1 = '1';
    this.param2 = 2;
    this.function1 = function () {
    };
};
console.log();
console.log('===');
console.log('=== Without cloning');
console.log('===');
console.log();
testingWithoutClone(new MyObjectWithFunction());
console.log();
console.log('===');
console.log('=== With cloning');
console.log('===');
console.log();
testingWithClone(new MyObjectWithFunction());
console.log();
console.log('========================================================================');
console.log();
displayTestingResult();