Socket
Book a DemoInstallSign in
Socket

proxyequal

Package Overview
Dependencies
Maintainers
1
Versions
36
Alerts
File Explorer

Advanced tools

Socket logo

Install Socket

Detect and block malicious and high-risk dependencies

Install

proxyequal

A proxy based usage tracking and comparison

2.1.3
latest
Source
npmnpm
Version published
Maintainers
1
Created
Source

proxyequal

CircleCI status Greenkeeper badge

Shallow equal is a good thing, but it compares thing you don't need.

Proxy equal - "MobX"-like solution, which will "magically" compare only used keys.

NPM

Usage

  • Wrap an object with proxyState

  • Run some computations using providing proxyObject. proxyState returns object with shape

    • state - a double of provided state, with tracking enabled
    • affected - list of used keys in a state.
    • seal - disables tracking
    • unseal - enabled tracking
    • replaceState(newState) - replaces top level state, maintaining rest of data.
    • reset - resets tracked keys
  • proxy will collect all referenced or used keys

  • proxyEqual will compare all used "endpoint" keys of 2 objects

  • proxyShallow will compare all used NON "endpoint" keys of 2 objects.

The difference between proxyEqual and proxyShallow is in expectations.

  • proxyShallow is similar to shallowEqual, it compares the top level objects. Might be they are still the same.
  • proxyEqual working on variable-value level, performing (very) deep comparison of objects.

Extra API

  • spreadGuardsEnabled(boolean=[true]) - controls spread guards, or all-keys-enumeration, which makes proxyEqual ineffective.
  • sourceMutationsEnabled(boolean=[false]) - controls set behavior. By default proxied state is frozen.

When to use proxyequal

When you have a big state, for example redux state, but some function (redux selector, or mapStateToProps) uses just a small subset.

Here proxyequal can shine, detecting the only used branches, and comparing only the used keys.

Example

import {proxyState, proxyEqual, proxyShallow} from 'proxyequal';

// wrap the original state
const trapped = proxyState(state);

// use provided one in computations
mapStateToProps(trapped.state);

// first shallow compare
proxyShallow(state, newState, trapped.affected);

// next - deep compare
proxyEqual(state, newState, trapped.affected);

Don't forget to disable

const trapped = proxyState(state);
// do something
workWith(trapped.state);

trapped.seal();

// now tracking is disabled

trapped.unseal();
// and enabled

Speed

Uses ES6 Proxy underneath to detect used branches(as MobX), and search-trie to filter out keys for shallow or equal compare.

So - it is lighting fast.

Limitations

Unfortunately, due to Proxy wrappers all objects will be unique each run.

 shallowEqual(proxyState(A), proxyState(A)) === false

There is a undocumented way to solve it, used internally in memoize-state library. Once it will be proven to work stable - we will expose it.

Compatibility

Requires Proxy support, so the proxy-polyfill is included in the common bundle for Internet Explorer 11. How this works may change in future, see issue #15 "ProxyPolyfill is unconditionally imported" for details.

Licence

MIT

Keywords

shallowequal

FAQs

Package last updated on 22 Apr 2020

Did you know?

Socket

Socket for GitHub automatically highlights issues in each pull request and monitors the health of all your open source dependencies. Discover the contents of your packages and block harmful activity before you install or update your dependencies.

Install

Related posts

SocketSocket SOC 2 Logo

Product

About

Packages

Stay in touch

Get open source security insights delivered straight into your inbox.

  • Terms
  • Privacy
  • Security

Made with ⚡️ by Socket Inc

U.S. Patent No. 12,346,443 & 12,314,394. Other pending.