source: trip-planner-front/node_modules/call-bind/test/index.js

'use strict';

var callBind = require('../');
var bind = require('function-bind');

var test = require('tape');

/*
 * older engines have length nonconfigurable
 * in io.js v3, it is configurable except on bound functions, hence the .bind()
 */
var functionsHaveConfigurableLengths = !!(
        Object.getOwnPropertyDescriptor
        && Object.getOwnPropertyDescriptor(bind.call(function () {}), 'length').configurable
);

test('callBind', function (t) {
        var sentinel = { sentinel: true };
        var func = function (a, b) {
                // eslint-disable-next-line no-invalid-this
                return [this, a, b];
        };
        t.equal(func.length, 2, 'original function length is 2');
        t.deepEqual(func(), [undefined, undefined, undefined], 'unbound func with too few args');
        t.deepEqual(func(1, 2), [undefined, 1, 2], 'unbound func with right args');
        t.deepEqual(func(1, 2, 3), [undefined, 1, 2], 'unbound func with too many args');

        var bound = callBind(func);
        t.equal(bound.length, func.length + 1, 'function length is preserved', { skip: !functionsHaveConfigurableLengths });
        t.deepEqual(bound(), [undefined, undefined, undefined], 'bound func with too few args');
        t.deepEqual(bound(1, 2), [1, 2, undefined], 'bound func with right args');
        t.deepEqual(bound(1, 2, 3), [1, 2, 3], 'bound func with too many args');

        var boundR = callBind(func, sentinel);
        t.equal(boundR.length, func.length, 'function length is preserved', { skip: !functionsHaveConfigurableLengths });
        t.deepEqual(boundR(), [sentinel, undefined, undefined], 'bound func with receiver, with too few args');
        t.deepEqual(boundR(1, 2), [sentinel, 1, 2], 'bound func with receiver, with right args');
        t.deepEqual(boundR(1, 2, 3), [sentinel, 1, 2], 'bound func with receiver, with too many args');

        var boundArg = callBind(func, sentinel, 1);
        t.equal(boundArg.length, func.length - 1, 'function length is preserved', { skip: !functionsHaveConfigurableLengths });
        t.deepEqual(boundArg(), [sentinel, 1, undefined], 'bound func with receiver and arg, with too few args');
        t.deepEqual(boundArg(2), [sentinel, 1, 2], 'bound func with receiver and arg, with right arg');
        t.deepEqual(boundArg(2, 3), [sentinel, 1, 2], 'bound func with receiver and arg, with too many args');

        t.test('callBind.apply', function (st) {
                var aBound = callBind.apply(func);
                st.deepEqual(aBound(sentinel), [sentinel, undefined, undefined], 'apply-bound func with no args');
                st.deepEqual(aBound(sentinel, [1], 4), [sentinel, 1, undefined], 'apply-bound func with too few args');
                st.deepEqual(aBound(sentinel, [1, 2], 4), [sentinel, 1, 2], 'apply-bound func with right args');

                var aBoundArg = callBind.apply(func);
                st.deepEqual(aBoundArg(sentinel, [1, 2, 3], 4), [sentinel, 1, 2], 'apply-bound func with too many args');
                st.deepEqual(aBoundArg(sentinel, [1, 2], 4), [sentinel, 1, 2], 'apply-bound func with right args');
                st.deepEqual(aBoundArg(sentinel, [1], 4), [sentinel, 1, undefined], 'apply-bound func with too few args');

                var aBoundR = callBind.apply(func, sentinel);
                st.deepEqual(aBoundR([1, 2, 3], 4), [sentinel, 1, 2], 'apply-bound func with receiver and too many args');
                st.deepEqual(aBoundR([1, 2], 4), [sentinel, 1, 2], 'apply-bound func with receiver and right args');
                st.deepEqual(aBoundR([1], 4), [sentinel, 1, undefined], 'apply-bound func with receiver and too few args');

                st.end();
        });

        t.end();
});