object-resolve-path

a simple utility function for getting a value at a path from an object with all the usecases properly covered. Based on Path pseodoclass from https://github.com/Polymer/observe-js/blob/7e94bb14d7c44b221af7bcc874cf9898f26747d8/src/observe.js#L305

Install

npm i object-resolve-path -S

Usage

const resolvePath = require('object-resolve-path');
resolvePath(someObject, 'a.b[0]');	//returns first property from b from a from someObject
resolvePath(someObject, 'a["b-a"][0]');	//this works as well, thanks to the parser/statemachine
//with variables
const someId = 'some-id'
resolvePath(someObject, `a.b['${someId}']`); //return key 'some-id' from the nested a.b object

Typical usecase?

Most other libraries for accessing deeply nested properties of an object don't work with bracket syntax. This one does work with bracket syntax.

For thorough description, check the tests.

Similar modules:

https://www.npmjs.com/package/lodash.get (works for both but much much slower, doesn't throw when path is not valid, object-resolve-path does)

https://github.com/deoxxa/dotty (works only for dots)

https://github.com/Ntran013/dot-access (works only for dots)

https://github.com/substack/js-traverse (much more complex and useful)

Benchmarks

node benchmark.js
lodash.get x 2,253,484 ops/sec ±0.83% (94 runs sampled)
object-resolve-path x 39,876,349 ops/sec ±0.82% (92 runs sampled)
Fastest is object-resolve-path