/* eslint no-new-func: 0 */

import createChainedFunction from '../../src/utils/createChainedFunction';

describe('createChainedFunction', () => {

it('returns null with no arguments', () => {

expect(createChainedFunction()).to.equal(null);

});

it('returns original function when single function is provided', () => {

const func1 = sinon.stub();

createChainedFunction(func1).should.equal(func1);

});

it('wraps two functions with another that invokes both when called', () => {

const func1 = sinon.stub();

const func2 = sinon.stub();

const chained = createChainedFunction(func1, func2);

chained

.should.not.equal(func1)

.and.should.not.equal(func2);

func1.should.not.have.been.called;

func2.should.not.have.been.called;

chained();

func1.should.have.been.calledOnce;

func2.should.have.been.calledOnce;

});

it('wraps multiple functions and invokes them in the order provided', () => {

const results = [];

const func1 = () => results.push(1);

const func2 = () => results.push(2);

const func3 = () => results.push(3);

const chained = createChainedFunction(func1, func2, func3);

chained();

results.should.eql([1, 2, 3]);

});

it('forwards arguments to all chained functions', () => {

const in1 = 'herpa derpa';

const in2 = {

herpa: 'derpa'

};

const func = (arg1, arg2) => {

arg1.should.equal(in1);

arg2.should.equal(in2);

};

const chained = createChainedFunction(func, func, func);

chained(in1, in2);

});

it('throws when func is not provided', () => {

expect(() => {

createChainedFunction({ herpa: 'derpa' });

}).to.throw(/Invalid Argument Type/);

});

it('works with new Function call', () => {

const results = [];

const func1 = new Function('results', 'results.push(1);');

const func2 = new Function('results', 'results.push(2);');

const chained = createChainedFunction(func1, func2);

chained(results);

results.should.eql([1, 2]);

});

});