https://github.com/wking-io/safe-prop

Safe property checks with Either ADT.
https://github.com/wking-io/safe-prop

Last synced: about 1 month ago
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Safe property checks with Either ADT.

• Host: GitHub
• URL: https://github.com/wking-io/safe-prop
• Owner: wking-io
• License: mit
• Created: 2018-11-09T04:20:47.000Z (about 6 years ago)
• Default Branch: master
• Last Pushed: 2018-11-20T17:50:13.000Z (almost 6 years ago)
• Last Synced: 2024-10-10T11:20:50.152Z (about 1 month ago)
• Language: JavaScript
• Homepage:
• Size: 192 KB
• Stars: 1
• Watchers: 3
• Forks: 0
• Open Issues: 1
• Metadata Files:
  • Readme: README.md
  • License: LICENSE.md

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README

        
![logo](./safe-prop-logo.png)

[![Build Status](https://travis-ci.org/wking-io/safe-prop.svg?branch=master)](https://travis-ci.org/wking-io/safe-prop)

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A micro-library for safe handling of object properties using the Either ADT from `data.either`.

## API

You can review the API below or take an interactive look in [CodeSandbox](https://codesandbox.io/s/x2xy3nzl9w)

### `# safeProp(prop, obj)`

```js

// safeProp : String -> Object -> Either Error Value

import { safeProp } from 'safe-prop';

const obj = { value: 1, empty: null };

safeProp("fake", obj);  // Either.Left(`The property "fake" does not exist on the passed in object.`)

safeProp("empty", obj); // Either.Left(`The value for the property "empty" is either null or undefined on the passed in object.`)

safeProp("value", obj); // Either.Right(1)

```

Safely check if prop exists on object. Returns `Either.Left` if it doesn't exists or the value of the property is Nullable and `Either.Right` with the value of the property if it does.

### `# safePath([..props], obj)`

```js

// safeProp : Array String -> Object -> Either Error Value

import { safePath } from 'safe-prop';

const obj = { one: { two: { value: 1, empty: null } } };

safeProp(["fake"], obj);  // Either.Left(`The property "fake" does not exist on the passed in object.`)

safeProp(["one", "three", "value"], obj);  // Either.Left(`The property "three" does not exist on the passed in object.`)

safeProp(["one", "two", "empty"], obj); // Either.Left(`The value for the property "empty" is either null or undefined on the passed in object.`)

safeProp(["one", "two", "value"], obj); // Either.Right(1)

```

Safely check if nested prop exists on path for an object. Returns `Either.Left` if the path doesn't exists or the value of the property is Nullable and `Either.Right` with the value of the property if it does.