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

@madappgang/update-by-path

v1.1.19

Published

Easy deep immutable updates to objects

Downloads

587

Readme

Update by path

Build Status Coverage Status

Intent

It is a function that allows to make immutable alterations to objects. It's meant to reduce the code needed to update a deep value without any mutations. It brings readability by reducing the verbosity.

Installation

As simple as that

npm i --save @madappgang/update-by-path

import update from '@madappgang/update-by-path';

Real-world example

I find this package extremely useful with redux reducers, so I'm going to use one of those as an example.

First off, let's take a look at what a simple reducer would look like without this package.

  const INITIAL_STATE = {
    isFetching: false,
    list: [],
    error: null,
  };

  export default (state = INITIAL_STATE, action) => {
    const { type, payload } = action;

    switch (type) {
      case types.FETCH_ATTEMPT:
        return {
          ...state,
          isFetching: true,
        };
      case types.FETCH_SUCCESS:
        return {
          ...state,
          isFetching: false,
          list: payload,
        };
      default:
        return state;
    }
  };

It can be a lot shorter if we use update from the package

...

case types.FETCH_ATTEMPT:
  return update(state, { isFetching: true });
case types.FETCH_SUCCESS:
  return update(state, { isFetching: false, list: payload });
default:
  return state;

...
};

Same result. What about a bit more complex alterations?

Here we got to replace a list element by id:

...

case types.REPLACE_BY_ID
  return {
    ...state,
    list: state.list.map((element) => {
      if (element.id === payload.id) {
        return payload;
      }
      return element;
    });
  };

...

Let's apply the update function:

...

case types.REPLACE_BY_ID:
  return update(state, `list[id=${payload.id}]`, payload);

...

Still a single line, and still completely immutable.

API

It accepts either 2, or 3 arguments.

update(object, 'deep.path.to.prop', valueToInsert);

update(object, {
  'deep.path.to.props': valueToInsert,
  'another.path': valueToInsert,
});

They are completely identical, though the second option allows to make multiple insertions at a time.

Create new nodes

If the path contains nodes that do not exist in the source object, they are going to be created

update({}, 'deep.path', 'value');
// { deep: { path: 'value' } }

Use function as a value

If you need to generate next value based on the previous one, use a function

const user = {
  name: 'John',
};

update(user, {
  name: name => name.toUpperCase(),
});
// { name: 'JOHN' }

Go deep inside arrays

By value

const user = {
  skills: ['html', 'javascript'],
};

update(user, `skills[javascript]`, 'JavaScript');
// { skills: ['html', 'JavaScript' ] }

By index

const user = {
  skills: ['html', 'javascript'],
};

update(user, `skills[0]`, skill => skill.toUpperCase());
// { skills: ['HTML', 'javascript' ] }

By property value

const user = {
  skills: [{ name: 'html'}, { name: 'javascript' }],
};

update(user, `skills[name=javascript]`, { name: 'JavaScript' });
// { skills: [{ name: 'html'}, { name: 'JavaScript' }] },

If there are no matches for your query the source object remains intact.

Go even deeper inside array elements.

Alter a property of the matching array element. It doesn't metter which kind of query to use to match the element.

const user = {
  skills: [{ name: 'html'}, { name: 'javascript' }],
};

update(user, `skills[name=html].name`, name => name.toUpperCase());
// { skills: [{ name: 'HTML'}, { name: 'javascript' }] },

Contribute

First off, thanks for taking the time to contribute! Now, take a moment to be sure your contributions make sense to everyone else.

LICENSE

This project is licensed under the MIT License - see the LICENSE file for details.