odin-js-fundamentals-part-5/node_modules/safe-array-concat/test/index.js

90 lines
2.6 KiB
JavaScript

'use strict';
var test = require('tape');
var mockProperty = require('mock-property');
var hasSymbols = require('has-symbols/shams')();
var isConcatSpreadable = hasSymbols && Symbol.isConcatSpreadable;
var species = hasSymbols && Symbol.species;
var boundFnsHaveConfigurableLengths = Object.getOwnPropertyDescriptor && Object.getOwnPropertyDescriptor(function () {}.bind(), 'length').configurable;
var safeConcat = require('../');
test('safe-array-concat', function (t) {
t.equal(typeof safeConcat, 'function', 'is a function');
t.equal(
safeConcat.length,
boundFnsHaveConfigurableLengths ? 1 : 0,
'has a length of ' + (boundFnsHaveConfigurableLengths ? 1 : '0 (function lengths are not configurable)'),
'length is as expected'
);
t.deepEqual(
safeConcat([1, 2], [3, 4], 'foo', 5, 6, [[7]]),
[1, 2, 3, 4, 'foo', 5, 6, [7]],
'works with flat and nested arrays'
);
t.deepEqual(
safeConcat(undefined, 1, 2),
[undefined, 1, 2],
'first item as undefined is not the concat receiver, which would throw via ToObject'
);
t.deepEqual(
safeConcat(null, 1, 2),
[null, 1, 2],
'first item as null is not the concat receiver, which would throw via ToObject'
);
var arr = [1, 2];
arr.constructor = function C() {
return { args: arguments };
};
t.deepEqual(
safeConcat(arr, 3, 4),
[1, 2, 3, 4],
'first item as an array with a nonArray .constructor; ignores constructor'
);
t.test('has Symbol.species', { skip: !species }, function (st) {
var speciesArr = [1, 2];
speciesArr.constructor = {};
speciesArr.constructor[species] = function Species() {
return { args: arguments };
};
st.deepEqual(
safeConcat(speciesArr, 3, 4),
[1, 2, 3, 4],
'first item as an array with a .constructor object with a Symbol.species; ignores constructor and species'
);
st.end();
});
t.test('has isConcatSpreadable', { skip: !isConcatSpreadable }, function (st) {
st.teardown(mockProperty(String.prototype, isConcatSpreadable, { value: true }));
var nonSpreadable = [1, 2];
nonSpreadable[isConcatSpreadable] = false;
st.deepEqual(
safeConcat(nonSpreadable, 3, 4, 'foo', Object('bar')),
[1, 2, 3, 4, 'foo', Object('bar')],
'a non-concat-spreadable array is spreaded, and a concat-spreadable String is not spreaded'
);
st.teardown(mockProperty(Array.prototype, isConcatSpreadable, { value: false }));
st.deepEqual(
safeConcat([1, 2], 3, 4, 'foo', Object('bar')),
[1, 2, 3, 4, 'foo', Object('bar')],
'all arrays marked non-concat-spreadable are still spreaded, and a concat-spreadable String is not spreaded'
);
st.end();
});
t.end();
});