json-multi-parse

This is a simple Node module to parse multiple JSON objects from a single source, such as the following:

{"object 1": "value 1"}{"object 2":"value 2"}

There can be whitespace between objects. Bare JSON types other than objects, like strings, arrays, booleans, and numbers, may or may not be supported depending on the Javascript engine being used.

An array is always returned on success. Otherwise, an error thrown by JSON.parse is rethrown.

Regex solutions such as splitting on }{ won't work since that could appear in a string inside the JSON object.

An option partial is available to handle ending partway through a JSON object. If this is enabled, and such an unexpected ending is encountered, the returned array will have an extra property remainder containing the remaining partial JSON string.

Typescript types are included.

Installation

npm install json-multi-parse

Usage

jsonMultiParse = require('json-multi-parse');

parsed = jsonMultiParse('{"object 1": "value 1"}{"object 2":"value 2"}');
console.log(parsed.length); // 2
console.log(parsed.remainder); // undefined

parsed = jsonMultiParse('{"object 1": "value 1"}{"object 2":"value 2"}', {partial: true});
console.log(parsed.length); // 2
console.log(parsed.remainder); // ''

parsed = jsonMultiParse('{"object 1": "value 1"}{"obje', {partial: true});
console.log(parsed.length); // 1
console.log(parsed.remainder); // '{"obje'

Typescript

The default type of each item of the returned array is any. This can be overridden if you are certain of what you will be receiving, by passing a type to the generic:

const parsed = jsonMultiParse<MyObjectType>('...'); // MyObjectType[]

If you are not totally certain about the data you're receiving, like if it's from a 3rd-party API or from user input, it's safer to do some type validation/narrowing, such as via type predicates, or maybe using something like Zod.

Warning

This relies on the error message JSON.parse throws when trying to parse such a string. It may therefore be brittle.