You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
167 lines
6.5 KiB
167 lines
6.5 KiB
# react-fast-compare
|
|
|
|
[![Downloads][downloads_img]][npm_site]
|
|
[![Bundle Size][bundle_img]](#bundle-size)
|
|
[![Travis Status][trav_img]][trav_site]
|
|
[![AppVeyor Status][appveyor_img]][appveyor_site]
|
|
[![Coverage Status][cov_img]][cov_site]
|
|
[![npm version][npm_img]][npm_site]
|
|
[![Maintenance Status][maintenance_img]](#maintenance-status)
|
|
|
|
The fastest deep equal comparison for React. Very quick general-purpose deep
|
|
comparison, too. Great for `React.memo` and `shouldComponentUpdate`.
|
|
|
|
This is a fork of the brilliant
|
|
[fast-deep-equal](https://github.com/epoberezkin/fast-deep-equal) with some
|
|
extra handling for React.
|
|
|
|
|
|
|
|
(Check out the [benchmarking details](#benchmarking-this-library).)
|
|
|
|
## Install
|
|
|
|
```sh
|
|
$ yarn add react-fast-compare
|
|
# or
|
|
$ npm install react-fast-compare
|
|
```
|
|
|
|
## Highlights
|
|
|
|
- ES5 compatible; works in node.js (0.10+) and browsers (IE9+)
|
|
- deeply compares any value (besides objects with circular references)
|
|
- handles React-specific circular references, like elements
|
|
- checks equality Date and RegExp objects
|
|
- should as fast as [fast-deep-equal](https://github.com/epoberezkin/fast-deep-equal) via a single unified library, and with added guardrails for circular references.
|
|
- small: under 650 bytes minified+gzipped
|
|
|
|
## Usage
|
|
|
|
```jsx
|
|
const isEqual = require("react-fast-compare");
|
|
|
|
// general usage
|
|
console.log(isEqual({ foo: "bar" }, { foo: "bar" })); // true
|
|
|
|
// React.memo
|
|
// only re-render ExpensiveComponent when the props have deeply changed
|
|
const DeepMemoComponent = React.memo(ExpensiveComponent, isEqual);
|
|
|
|
// React.Component shouldComponentUpdate
|
|
// only re-render AnotherExpensiveComponent when the props have deeply changed
|
|
class AnotherExpensiveComponent extends React.Component {
|
|
shouldComponentUpdate(nextProps) {
|
|
return !isEqual(this.props, nextProps);
|
|
}
|
|
render() {
|
|
// ...
|
|
}
|
|
}
|
|
```
|
|
|
|
## Do I Need `React.memo` (or `shouldComponentUpdate`)?
|
|
|
|
> What's faster than a really fast deep comparison? No deep comparison at all.
|
|
|
|
—This Readme
|
|
|
|
Deep checks in `React.memo` or a `shouldComponentUpdate` should not be used blindly.
|
|
First, see if the default
|
|
[React.memo](https://reactjs.org/docs/react-api.html#reactmemo) or
|
|
[PureComponent](https://reactjs.org/docs/react-api.html#reactpurecomponent)
|
|
will work for you. If it won't (if you need deep checks), it's wise to make
|
|
sure you've correctly indentified the bottleneck in your application by
|
|
[profiling the performance](https://reactjs.org/docs/optimizing-performance.html#profiling-components-with-the-chrome-performance-tab).
|
|
After you've determined that you _do_ need deep equality checks and you've
|
|
identified the minimum number of places to apply them, then this library may
|
|
be for you!
|
|
|
|
## Benchmarking this Library
|
|
|
|
The absolute values are much less important than the relative differences
|
|
between packages.
|
|
|
|
Benchmarking source can be found
|
|
[here](https://github.com/FormidableLabs/react-fast-compare/blob/master/benchmark/index.js).
|
|
Each "operation" consists of running all relevant tests. The React benchmark
|
|
uses both the generic tests and the react tests; these runs will be slower
|
|
simply because there are more tests in each operation.
|
|
|
|
The results below are from a local test on a laptop.
|
|
|
|
### Generic Data
|
|
|
|
```
|
|
react-fast-compare x 157,863 ops/sec ±0.54% (94 runs sampled)
|
|
fast-deep-equal x 149,877 ops/sec ±0.76% (93 runs sampled)
|
|
lodash.isEqual x 33,298 ops/sec ±0.70% (93 runs sampled)
|
|
nano-equal x 144,836 ops/sec ±0.51% (94 runs sampled)
|
|
shallow-equal-fuzzy x 110,192 ops/sec ±0.57% (95 runs sampled)
|
|
fastest: react-fast-compare
|
|
```
|
|
|
|
`react-fast-compare` and `fast-deep-equal` should be the same speed for these
|
|
tests; any difference is just noise. `react-fast-compare` won't be faster than
|
|
`fast-deep-equal`, because it's based on it.
|
|
|
|
### React and Generic Data
|
|
|
|
```
|
|
react-fast-compare x 64,102 ops/sec ±0.36% (94 runs sampled)
|
|
fast-deep-equal x 63,844 ops/sec ±0.43% (94 runs sampled)
|
|
lodash.isEqual x 6,243 ops/sec ±0.72% (90 runs sampled)
|
|
fastest: react-fast-compare,fast-deep-equal
|
|
```
|
|
|
|
Two of these packages cannot handle comparing React elements, because they
|
|
contain circular reference: `nano-equal` and `shallow-equal-fuzzy`.
|
|
|
|
### Running Benchmarks
|
|
|
|
```sh
|
|
$ yarn install
|
|
$ yarn run benchmark
|
|
```
|
|
|
|
## Differences between this library and `fast-deep-equal`
|
|
|
|
`react-fast-compare` is based on `fast-deep-equal`, with some additions:
|
|
|
|
- `react-fast-compare` has `try`/`catch` guardrails for stack overflows from undetected (non-React) circular references.
|
|
- `react-fast-compare` has a _single_ unified entry point for all uses. No matter what your target application is, `import equal from 'react-fast-compare'` just works. `fast-deep-equal` has multiple entry points for different use cases.
|
|
|
|
This version of `react-fast-compare` tracks `fast-deep-equal@3.1.1`.
|
|
|
|
## Bundle Size
|
|
|
|
There are a variety of ways to calculate bundle size for JavaScript code.
|
|
You can see our size test code in the `compress` script in
|
|
[`package.json`](https://github.com/FormidableLabs/react-fast-compare/blob/master/package.json).
|
|
[Bundlephobia's calculation](https://bundlephobia.com/result?p=react-fast-compare) is slightly higher,
|
|
as they [do not mangle during minification](https://github.com/pastelsky/package-build-stats/blob/v6.1.1/src/getDependencySizeTree.js#L139).
|
|
|
|
## License
|
|
|
|
[MIT](https://github.com/FormidableLabs/react-fast-compare/blob/readme/LICENSE)
|
|
|
|
## Contributing
|
|
|
|
Please see our [contributions guide](./CONTRIBUTING.md).
|
|
|
|
## Maintenance Status
|
|
|
|
**Active:** Formidable is actively working on this project, and we expect to continue for work for the foreseeable future. Bug reports, feature requests and pull requests are welcome.
|
|
|
|
[trav_img]: https://api.travis-ci.com/FormidableLabs/react-fast-compare.svg
|
|
[trav_site]: https://travis-ci.com/FormidableLabs/react-fast-compare
|
|
[cov_img]: https://codecov.io/gh/FormidableLabs/react-fast-compare/branch/master/graph/badge.svg
|
|
[cov_site]: https://codecov.io/gh/FormidableLabs/react-fast-compare
|
|
[npm_img]: https://badge.fury.io/js/react-fast-compare.svg
|
|
[npm_site]: http://badge.fury.io/js/react-fast-compare
|
|
[appveyor_img]: https://ci.appveyor.com/api/projects/status/github/formidablelabs/react-fast-compare?branch=master&svg=true
|
|
[appveyor_site]: https://ci.appveyor.com/project/FormidableLabs/react-fast-compare
|
|
[bundle_img]: https://img.shields.io/badge/minzipped%20size-639%20B-flatgreen.svg
|
|
[downloads_img]: https://img.shields.io/npm/dm/react-fast-compare.svg
|
|
[maintenance_img]: https://img.shields.io/badge/maintenance-active-flatgreen.svg
|