Template Method Pattern in Javascript using prototypes

template-pattern.js

/**
 * Parent Class A
 */
function A() {
	this.name = 'Clase A';
}

A.prototype.function2 = function() {
	console.log( 'Function 2 in A' );
};

A.prototype.function3 = function() {
	console.log( 'Function 3 in A' );
};

/**
 * Template function. We will override function2 and function3 in child classes
 */
A.prototype.function1 = function() {
	this.function2();
	this.function3();
};

/**
 * Child class B
 */
function B() {
	// We could omit this line since there are no properties to share.
	A.call( this );
}
// We copy the A prototype into B, so it has function1, function2 and function3.
B.prototype = Object.create( A.prototype );

// We override function2 and function3
B.prototype.function2 = function() {
	console.log( 'Function 2 in B' );
};

B.prototype.function3 = function() {
	console.log( 'Function 3 in B' );
};

/**
 * Child class C
 */
function C() {
	// We could omit this line since there are no properties to share.
	A.call( this );
}

// We copy the A prototype into C, so it has function1, function2 and function3.
C.prototype = Object.create( A.prototype );

// We override function2 and function3
C.prototype.function2 = function() {
	console.log( 'Function 2 in C' );
};

C.prototype.function3 = function() {
	console.log( 'Function 3 in C' );
};


const b = new B();
const c = new C();
b.function1();
// Function 2 in B
// Function 3 in B
c.function1();
// Function 2 in C
// Function 3 in C