urltomarkdown/node_modules/call-bind/test/index.js

67 lines
3.3 KiB
JavaScript
Executable File

'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();
});