js-oop/js/Interface.js

jsOOP aids in object oriented programming in JS.

var Interface = function( descriptor ) {
	this.descriptor = descriptor;
};

Interface.prototype.descriptor = null;

Interface.prototype.compare = function( classToCheck ) {

	for( var i  in this.descriptor ) {
		// First we'll check if this property exists on the class
		if( classToCheck.prototype[ i ] === undefined ) {

			throw 'INTERFACE ERROR: ' + i + ' is not defined in the class';

		// Second we'll check that the types expected match
		} else if( typeof this.descriptor[ i ] != typeof classToCheck.prototype[ i ] ) {

			throw 'INTERFACE ERROR: Interface and class define items of different type for ' + i + 
				  '\ninterface[ ' + i + ' ] == ' + typeof this.descriptor[ i ] +
				  '\nclass[ ' + i + ' ] == ' + typeof classToCheck.prototype[ i ];

		// Third if this property is a function we'll check that they expect the same amount of parameters
		} else if( typeof this.descriptor[ i ] == 'function' && classToCheck.prototype[ i ].length != this.descriptor[ i ].length ) {

			throw 'INTERFACE ERROR: Interface and class expect a different amount of parameters for the function ' + i +
				  '\nEXPECTED: ' + this.descriptor[ i ].length + 
				  '\nRECEIVED: ' + classToCheck.prototype[ i ].length;

		}
	}
};

module.exports = Interface;