babel-plugin-object-to-json-parse 🚀

This repository is inspired by this article

As long as the JSON string is only evaluated once, the JSON.parse approach is much faster compared to the JavaScript object literal, especially for cold loads.

Object to JSON.parse

This plugin converts from object literal to JSON.parse (example)

// before
const data = { foo: 42, bar: 1337 };

// after
const data = JSON.parse('{"foo":42,"bar":1337}');

How to use

Install

$ npm install babel-plugin-object-to-json-parse -D
or
$ yarn add babel-plugin-object-to-json-parse -D

setup .babelrc

{
  "plugins": ["object-to-json-parse"]
}

Options

minJSONStringSize (number, defaults to 1024)

The minJSONStringSize option will prevent the plugin from replacing an expression if the length of the JSON string given to JSON.parse is smaller than minJSONStringSize. For example, the following ensures all replacements have a string size of at least 1kb.

{
  "plugins": [
    ["object-to-json-parse", {
      "minJSONStringSize": 1024
    }]
  ]
}

Caution!!

this plugin may not be production ready

I just made this plugin for my understanding about AST and babel plugin.

this plugin doesn't support partially JSON expression

I decided not to support partially JSON expression like below.

Partially JSON expressions such as [notValid, {isValid:true}] ensuring {isValid:true} is transformed.

const data = { bar: invalid_object, foo: 'foo' }
↓
const data = { bar: invalid_object, JSON.parse('{"foo": "foo"}')}

This is because I think most large objects are not partially JSON expressions. JSON.parse() is much faster in the case that object is 10 kB or larger. Converting small object to JSON.parse expression is not meaningful.

this plugin produces output that only works in modern environments (e.g. Node.js v10+)

I don't care about some backwards compatibilities like this issue.

Development

Setup

$ git clone [email protected]:nd-02110114/babel-plugin-object-to-json-parse.git
$ cd babel-plugin-object-to-json-parse
$ yarn install

Tips

// example
$ yarn build && yarn example

// test
$ yarn test