jq-wasm

A fork of jq-web, the WebAssembly build of jq.

I forked the main project to have more control over the build process and the API interface, since it's a core component of Virtual Json Viewer browser extension.

Highlights

• jq version ~1.8
• emcc version ~4.0
• Straightforward client API
• Typescript support
• Docker toolchain setup
• No Git submodules

Quickstart

var newJQ = require('jq-wasm')
const jq = await newJQ()
const output = await jq.invoke('{"jq": {"is": "awesome"}}', ".jq.is")
// "awesome"

Installation

The easiest way is to download the build output directly from the releases page:

File	Description
jq.wasm.js	Javascript interface for interacting with JQ
jq.wasm	JQ WebAssembly binary, loaded by jq.wasm.js
jq.wasm.d.ts	Typescript types definition

Reference

newJQ(module?): Promise<JQ>

Return a promise that resolves into a JQ instance after the WebAssembly runtime has been initialized.

It accepts an optional module object to overwrite emscripten default parameters.
Example: customize the path of the wasm file with newJQ({locateFile: () => "path/to/jq.wasm"})

For a complete list of available options, see the emscripten official documentation

jq.invoke(input, filter, options): Promise<string>

Run jq and return the content of stdout on success.
It's equivalent to echo <input> | jq <options> <filter>

Build

Make sure you have Docker installed and then simply

docker compose run --rm emsdk make

Output files will be in dist folder.

Yarn

It's suggested to also have Yarn installed, in order to run tests and make sure everything works as expected

# shorter alias for building jq through docker
yarn make

# run smoke tests with Javascript
yarn test