https://github.com/thebearingedge/type-diff

Simple, readable, structural type comparisons.
https://github.com/thebearingedge/type-diff

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Simple, readable, structural type comparisons.

• Host: GitHub
• URL: https://github.com/thebearingedge/type-diff
• Owner: thebearingedge
• License: mit
• Created: 2016-07-30T16:31:49.000Z (over 8 years ago)
• Default Branch: master
• Last Pushed: 2020-07-19T22:37:48.000Z (over 4 years ago)
• Last Synced: 2024-09-19T05:41:06.929Z (about 2 months ago)
• Language: TypeScript
• Homepage:
• Size: 162 KB
• Stars: 1
• Watchers: 2
• Forks: 0
• Open Issues: 1
• Metadata Files:
  • Readme: README.md
  • License: LICENSE

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README

        
type-diff

--

Simple, readable, structural type comparisons.

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### Quick Example

```js

import assert from 'assert'

import { diff, Nullable, Optional, Any } from 'type-diff'

const Type = {

  id: Number,

  tags: [String]

  contacts: [{

    id: Number,

    name: String,

    contacted: Nullable(Date),

    tags: Optional([String]),

    wharrgarbl: Any()

  }]

}

const value = {

  id: 1,

  tags: ['good', 'cool'],

  contacts: [

    { id: 2, name: 'John Doe', contacted: null, wharrgarbl: _ => 'wheee' },

    { id: '3', name: 'Jane Doe', contacted: new Date(), tags: ['cool'] }

  ]

}

assert.deepEqual(diff(Type, value), {

  contacts: {

    '1': {

      id: {

        actual: 'String',

        expected: 'Number',

        value: '3'

      },

      wharrgarbl: {

        actual: 'Undefined',

        expected: 'Any'

      }

    }

  }

})

```

### Usage

`diff(Type, value)`

Generate an object literal representation of the difference between your `Type` and a given `value` as shown above in the [Quick Example](#quick-example).

### Supported Built-ins

- `Number`

- `String`

- `Boolean`

- `Object`

- `Array`

- `Date`

- `Function`

### Helpers

`Nullable(Type)`: Allows the corresponding `value` to be either the correct `Type` or `null`.

`Optional(Type)`: Allows the corresponding `value` to be either the correct `Type` or `undefined`.

`Any | Any()`: Requires that the corresponding value be anything but `undefined`. Used in conjuction with `Optional` if `undefined` is allowed; as in `Optional(Any)`