safe-array-concat

safe-array-concat

Array.prototype.concat, but made safe by ignoring Symbol.isConcatSpreadable

Getting started

npm install --save safe-array-concat

Usage/Examples

var safeConcat = require('safe-array-concat');
var assert = require('assert');

assert.deepEqual([].concat([1, 2], 3, [[4]]), [1, 2, 3, [4]], 'arrays spread as expected with normal concat');
assert.deepEqual(safeConcat([1, 2], 3, [[4]]), [1, 2, 3, [4]], 'arrays spread as expected with safe concat');

String.prototype[Symbol.isConcatSpreadable] = true;
assert.deepEqual([].concat('foo', Object('bar')), ['foo', 'b', 'a', 'r'], 'spreadable String objects are spread with normal concat!!!');
assert.deepEqual(safeConcat('foo', Object('bar')), ['foo', Object('bar')], 'spreadable String objects are not spread with safe concat');

Array.prototype[Symbol.isConcatSpreadable] = false;
assert.deepEqual([].concat([1, 2], 3, [[4]]), [[], [1, 2], 3, [[4]]], 'non-concat-spreadable arrays do not spread with normal concat!!!');
assert.deepEqual(safeConcat([1, 2], 3, [[4]]), [1, 2, 3, [4]], 'non-concat-spreadable arrays still spread with safe concat');

Tests

Simply clone the repo, npm install, and run npm test

Changelog

v1.1.3 - 2024-12-11

Commits

• [Dev Deps] update @arethetypeswrong/cli, @ljharb/eslint-config, @ljharb/tsconfig, @types/get-intrinsic, @types/tape, auto-changelog, mock-property, tape 9452ca7
• [actions] split out node 10-20, and 20+ 8166059
• [Deps] update call-bind, get-intrinsic, has-symbols d35014a
• [Refactor] use call-bound directly 0bdddbd
• [Tests] replace aud with npm audit c62dae0
• [Dev Deps] add missing peer dep 4860aae