# safe-array-concat [![Version Badge][npm-version-svg]][package-url]

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

## Getting started

```sh
npm install --save safe-array-concat
```

## Usage/Examples

```js
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`

[package-url]: https://npmjs.org/package/safe-array-concat
[npm-version-svg]: https://versionbadg.es/ljharb/safe-array-concat.svg
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[dev-deps-url]: https://david-dm.org/ljharb/safe-array-concat#info=devDependencies
[npm-badge-png]: https://nodei.co/npm/safe-array-concat.png?downloads=true&stars=true
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[license-url]: LICENSE
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[downloads-url]: https://npm-stat.com/charts.html?package=safe-array-concat
[codecov-image]: https://codecov.io/gh/ljharb/safe-array-concat/branch/main/graphs/badge.svg
[codecov-url]: https://app.codecov.io/gh/ljharb/safe-array-concat/
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[actions-url]: https://github.com/ljharb/safe-array-concat/actions
