demo jasmine

app.js

var checkForm = {

	checkInputs: function(user, pass) {

		var isValid = true;

		if ( !user || !pass || user.indexOf('@') === -1 ) {
			isValid = false;
		}

		return isValid;
	},

	init: function(user, pass) {
		this.checkInputs(user, pass);
	}
};

appSpecj.js

describe('checkForm', function() {

    var user = '',
        pass = '';

    afterEach(function() {
        user = '',
        pass = '';
     }); 
    
    it('checkForm must be an object', function() {
        expect(typeof checkForm).toBe('object');
    });

    it('checkForm has init method', function() {
        expect(typeof checkForm.init).toBe('function');
    });


    it('checkForm has checkInputs method', function() {
        expect(typeof checkForm.checkInputs).toBe('function');
    }); 

    it('inputs corrects are true', function() {
        user = '[email protected]';
        pass = 'bazinga';
        var inputs = checkForm.checkInputs(user, pass);
        expect(inputs).toBeTruthy();
    });

    it('empty inputs are false', function() {
        var inputs = checkForm.checkInputs(user, pass);
        expect(inputs).toBeFalsy();
    });

});