https://github.com/erikmueller/cond-flow

Elixir style cond for easy javascript control flow
https://github.com/erikmueller/cond-flow

conditions flow-control utilities

Last synced: about 2 months ago
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Elixir style cond for easy javascript control flow

• Host: GitHub
• URL: https://github.com/erikmueller/cond-flow
• Owner: erikmueller
• License: mit
• Created: 2020-03-20T20:33:35.000Z (over 4 years ago)
• Default Branch: master
• Last Pushed: 2024-04-10T07:45:18.000Z (6 months ago)
• Last Synced: 2024-05-14T00:30:05.439Z (4 months ago)
• Topics: conditions, flow-control, utilities
• Language: TypeScript
• Size: 252 KB
• Stars: 38
• Watchers: 2
• Forks: 1
• Open Issues: 0
• Metadata Files:
  • Readme: README.md
  • License: license

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README

        
# cond-flow

Inspired by [Elixir's `cond`](https://elixir-lang.org/getting-started/case-cond-and-if.html#cond) this is a simpler alternative to [lodash's `_.cond`](https://lodash.com/docs/4.17.15#cond)

[![codecov](https://codecov.io/gh/erikmueller/cond-flow/branch/master/graph/badge.svg?token=WCNYJSZK51)](https://codecov.io/gh/erikmueller/cond-flow)

## Install

Install with npm or yarn via

```sh

yarn add cond-flow

```

or

```sh

npm i cond-flow

```

## Usage

```js

import cond from 'cond-flow'

const value = cond([

  [false, 'false'],

  [true, 'true'],

  [true, 'true but too late'],

])

// value === 'true'

```

Also works nicely with React components as you can have the values lazily evaluated by wrapping them in a function:

```jsx

import cond from 'cond-flow'

const Component = ({ isDisabled, isNew, isLoading }) => (

  <>

    {cond([

      [isLoading, () => ],

      [isNew, () => ],

      [isDisabled, null],

    ])}

  >

)

```

### Default return value

You can provide a `default` fallback which will be returned if no provided conditions are met.

```js

import cond from 'cond-flow'

const value = cond(

  [

    [false, () => 'false'],

    [false, () => 'also false'],

  ],

  { default: () => 'fallback' },

)

// value === 'fallback'

```

### Note

As all predicates have to be evaluated before the right branch can be chosen, it can have a negative performance impact if you rely on heavy computations. It's best to have simple booleans and resort to [Ramda's](https://ramdajs.com/docs/#cond) `cond` for complex use cases.

## Development

If you find this useful or would like to add features, feel free to clone the repository and open a PR.