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https://github.com/moxio/js-struct-compare
Javascript library to compare two (JSON-serializable) structures and return their differences
https://github.com/moxio/js-struct-compare
compare diff javascript json structure
Last synced: 3 days ago
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Javascript library to compare two (JSON-serializable) structures and return their differences
- Host: GitHub
- URL: https://github.com/moxio/js-struct-compare
- Owner: Moxio
- License: mit
- Created: 2020-02-26T15:48:00.000Z (almost 5 years ago)
- Default Branch: master
- Last Pushed: 2024-02-26T10:59:52.000Z (10 months ago)
- Last Synced: 2024-12-24T02:09:56.582Z (3 days ago)
- Topics: compare, diff, javascript, json, structure
- Language: JavaScript
- Size: 368 KB
- Stars: 9
- Watchers: 12
- Forks: 3
- Open Issues: 0
-
Metadata Files:
- Readme: README.md
- License: LICENSE
Awesome Lists containing this project
README
[](https://www.npmjs.com/package/js-struct-compare)
js-struct-compare
=================
Javascript library to compare two (JSON-serializable) structures and return their
differences.
Installation
------------
This library can be installed from the NPM package registry. Using NPM:
```sh
npm install --save js-struct-compare
```
Or using Yarn:
```sh
yarn add js-struct-compare
```
Usage
-----
This package is meant to be consumed as an ES module. Its default export is a
comparison function that takes a _left_ and a _right_ instance and returns an
array of differences between them. These can be seen as the operations needed
to transform _left_ into _right_. An example:
```js
import compare from "js-struct-compare";
const left = {
"foo": {
"bar": [ 42, 0 ],
},
"qux": "quux",
"corge": "grault",
"garply": [],
};
const right = {
"foo": {
"bar": [ 43, 0 ],
"baz": 99,
},
"corge": "grault",
"garply": {},
};
const differences = compare(left, right);
// => [
// Difference{path: ['foo', 'bar', 0], type: 'changed', left_value: 42, right_value: 43},
// Difference{path: ['foo', 'baz'], type: 'added', left_value: undefined, right_value: 99},
// Difference{path: ['qux'], type: 'deleted', left_value: 'quux', right_value: undefined}
// Difference{path: ['garply'], type: 'changed', left_value: [], right_value: {}},
// ]
```
Each `Difference` object contains:
* A `path`: an array of path elements traversed to the location of the differences. The path
elements are strings in case of object properties and numbers in case of array keys.
* A `type`: describes the kind of difference. Can be one of the following:
* `Difference.TYPE_CHANGED = 'changed'`: both the _left_ and the _right_ instance have a
value at the given path, but these values are different.
* `Difference.TYPE_ADDED = 'added'`: the _left_ instance does not have a value at the
given path, but the _right_ instance does, i.e. the value was added in the transition
from _left_ to _right_.
* `Difference.TYPE_DELETED = 'deleted'`: the _left_ instance has a value at the given
path, but the _right_ instance does not, i.e. the value was deleted in the transition
from _left_ to _right_.
* A `left_value`: the value the _left_ instance has at the given path. Is `undefined` in case
of an addition. Can be a non-scalar value, i.e. a struct in itself.
* A `right_value`: the value the _right_ instance has at the given path. Is `undefined` in case
of a deletion. Can be a non-scalar value, i.e. a struct in itself.
The `Difference` and `Comparator` classes can be accessed separately as named exports:
```js
import { Difference, Comparator } from "js-struct-compare";
```
Versioning
----------
This project adheres to [Semantic Versioning](http://semver.org/).
Contributing
------------
Contributions to this project are more than welcome.
License
-------
This project is released under the MIT license.
---
Made with love, coffee and fun by the [Moxio](https://www.moxio.com) team from
Delft, The Netherlands. Interested in joining our awesome team? Check out our
[vacancies](https://werkenbij.moxio.com/) (in Dutch).