npm package discovery and stats viewer.

Discover Tips

  • General search

    [free text search, go nuts!]

  • Package details

    pkg:[package-name]

  • User packages

    @[username]

Sponsor

Optimize Toolset

I’ve always been into building performant and accessible sites, but lately I’ve been taking it extremely seriously. So much so that I’ve been building a tool to help me optimize and monitor the sites that I build to make sure that I’m making an attempt to offer the best experience to those who visit them. If you’re into performant, accessible and SEO friendly sites, you might like it too! You can check it out at Optimize Toolset.

About

Hi, 👋, I’m Ryan Hefner  and I built this site for me, and you! The goal of this site was to provide an easy way for me to check the stats on my npm packages, both for prioritizing issues and updates, and to give me a little kick in the pants to keep up on stuff.

As I was building it, I realized that I was actually using the tool to build the tool, and figured I might as well put this out there and hopefully others will find it to be a fast and useful way to search and browse npm packages as I have.

If you’re interested in other things I’m working on, follow me on Twitter or check out the open source projects I’ve been publishing on GitHub.

I am also working on a Twitter bot for this site to tweet the most popular, newest, random packages from npm. Please follow that account now and it will start sending out packages soon–ish.

Open Software & Tools

This site wouldn’t be possible without the immense generosity and tireless efforts from the people who make contributions to the world and share their work via open source initiatives. Thank you 🙏

© 2024 – Pkg Stats / Ryan Hefner

typed-get-prop

v1.1.5

Published

Strongly-typed function to get a nested & potentially null/undefined property value safely from an object

Downloads

135

Readme

npm version Build Status Coverage Status Greenkeeper badge

Install

npm install typed-get-prop --save

Usage

import { getProp } from 'typed-get-prop';

const movie: Movie = {
  title: 'The Matrix',
  year: 1999
  cast: [
    {
      name: 'Keanu Reeves',
      characters: [{
        name: 'Neo'
      }]
    },
    {
      name: 'Carrie-Anne Moss',
      characters: [{
        name: 'Trinity'
      }]
    }
  ]
};

const year = getProp(movie, 'year'); // number | undefined
const trinity = getProp(movie, 'cast', 1, 'characters', 0, 'name'); // string | undefined

Why do I need this?

  1. Because getting a nested property value can be error-prone when parent properties can be null or undefined.

    const movie: Movie = {
      title: 'Fight Club',
      year: 1999
    };
    
    // Next line will error because `cast` is optional and undefined
    const leadActor = movie.cast[0];
    
    // Using getProp will simply return undefined rather than erroring
    const leadActor = getProp(movie, 'cast', 0);
  2. Unlike most (if not all?) other property getter libraries on NPM, typed-get-prop will complain at design/compile-time if you try to access a property of a typed object that doesn't exist in the model.

    const movie: Movie = {
      title: 'The Matrix',
      year: 1999
      cast: [
        {
          name: 'Keanu Reeves',
          characters: [{
            name: 'Neo'
          }]
        }
      ]
    };
    
    // Next line will error at design/compile-time because `actors` isn't a property on the Movie type. It should be `cast`.
    const leadActor = getProp(movie, 'actors', 0);
  3. Again, unlike other property getter libraries, typed-get-prop will correctly infer types of properties.

    const movie: Movie = {
      title: 'The Matrix',
      year: 1999
      cast: [
        {
          name: 'Keanu Reeves',
          characters: [{
            name: 'Neo'
          }]
        }
      ]
    };
    
    const year = getProp(movie, 'year'); // year is number | undefined at design-time

Comparison with other npm libraries

| Library | Typesafe | Supports older browsers | Doesn't mutates Object.prototype | Doesn't swallow exceptions indiscriminately | :- | :-: | :-: | :-: | :-: | get-typed-prop | ✅ | ✅ | ✅ | ✅ | nevernull | ❌ | ❌ | ✅ | ✅ | telvis | ✅ | ❌ | ❌ | ✅ | ts-optchain | ✅ | ❌ Only via a custom compiler & transform | ✅ | ✅ | @smartlyio/safe-navigation | ✅ | ❌ | ✅ | ✅ | safe-ts | ✅ | ✅ | ✅ | ❌ | lonely-operation | ✅ | ❌ | ✅ | ✅

Contributing

Got an issue or a feature request? Log it.

Pull-requests are also welcome.