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

All notable changes to this project will be documented in this file.

The format is based on Keep a Changelog and this project adheres to Semantic Versioning.

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

v1.1.2 - 2024-03-09

Commits

• [types] use a generic a1d744d
• [Dev Deps] update @ljharb/tsconfig, set-function-length 3d3da0a

v1.1.1 - 2024-03-09

Commits

• [types] use shared config f509f80
• [actions] remove redundant finisher; use reusable workflows b5f5ff4
• [types] use handwritten d.ts instead of emit e717048
• [Dev Deps] update set-function-length, tape dde26a7
• [Deps] update call-bind, get-intrinsic d5d2cde
• [Dev Deps] update tape 9454c5a
• [Tests] add @arethetypeswrong/cli [00a5243`](https://github.com/ljharb/safe-array-concat/commit/00a5243a5b923ff2b694b3b5ef4ce39027e30f6e)
• [Deps] update get-intrinsic c935764

v1.1.0 - 2024-01-15

Commits

• [New] add types bd92413
• [Dev Deps] update aud, mock-property, npmignore, set-function-length, tape 497ffcb
• [Deps] update call-bind, get-intrinsic 770f870
• [Dev Deps] update mock-property, tape be76bd9
• [Tests] use set-function-length/env 89b1167
• [meta] add missing npmrc values 3185cc7
• [meta] add sideEffects flag df6c7eb

v1.0.1 - 2023-09-05

Fixed

• [Perf] set Symbol.isConcatSpreadable only when required #2

Commits

• [Dev Deps] update @ljharb/eslint-config, aud, tape c0791b0
• [Deps] update get-intrinsic 7d07ae6

v1.0.0 - 2023-04-20

Commits

• Initial implementation, tests, readme 31b8e70
• Initial commit 83d38c6
• npm init 516fdc2
• Only apps should have lockfiles 9cfa07b