https://github.com/andersdjohnson/null-propagation

Emulate null propagation operator.
https://github.com/andersdjohnson/null-propagation

ecmascript esnext facebook get idx javascript lodash null null-check path propagation stage-1 traversal traverse

Last synced: 16 days ago
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Emulate null propagation operator.

• Host: GitHub
• URL: https://github.com/andersdjohnson/null-propagation
• Owner: AndersDJohnson
• License: mit
• Created: 2017-05-17T03:48:23.000Z (over 7 years ago)
• Default Branch: master
• Last Pushed: 2023-01-12T06:49:11.000Z (almost 2 years ago)
• Last Synced: 2024-04-14T05:16:02.983Z (7 months ago)
• Topics: ecmascript, esnext, facebook, get, idx, javascript, lodash, null, null-check, path, propagation, stage-1, traversal, traverse
• Language: JavaScript
• Size: 484 KB
• Stars: 5
• Watchers: 2
• Forks: 1
• Open Issues: 15
• Metadata Files:
  • Readme: README.md
  • License: LICENSE

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README

        
# null-propagation

> Emulate null propagation operator.

Like [Facebook's `idx`][idx] and [Lodash's `get`][get],

but even more terse than the former, and real syntax unlike the latter.

The use of real syntax enables static analysis tools.

```js

import np from 'null-propagation'

const obj = {

  a: {

    b: 'B2'

  },

  z: []

}

````

For undefined values, returns undefined:

```js

const c = np(() => obj.a.c)

```

With a default as a 2nd argument, returns that value:

```js

const c2 = np(() => obj.a.c, 'C2')

```

For defined values, returns that value:

```js

const b = np(() => obj.a.b)

```

Works with arrays, returns undefined:

```js

const z = np(() => obj.z[0].y)

```

Throws other errors:

```js

np(() => { throw new Error('some error') })

```

[idx]: https://github.com/facebookincubator/idx

[get]: https://lodash.com/docs/4.17.4#get