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https://github.com/stainless-api/jq-web

Emscripten-compiled jq that is compatible with cloudflare workers
https://github.com/stainless-api/jq-web

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Emscripten-compiled jq that is compatible with cloudflare workers

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[![npm badge](https://img.shields.io/npm/v/jq-web.svg)](https://www.npmjs.com/package/jq-web) [![Mentioned in Awesome jq](https://awesome.re/mentioned-badge.svg)](https://github.com/fiatjaf/awesome-jq)

# jq-web (Cloudflare Workers Compatible Fork)

This is a fork of [jq-web](https://github.com/fiatjaf/jq-web) that is compatible with Cloudflare Workers and other JavaScript environments.

This is a WebAssembly build of [jq](https://github.com/jqlang/jq), the command-line JSON processor.

It runs in the browser, Node.js, and Cloudflare Workers.

## Why use this fork?

**Use this fork if you:**
- Need to run jq in Cloudflare Workers
- Want a simple, consistent API across all environments
- Prefer static bundling over dynamic WASM loading
- Are building libraries that need universal compatibility

**Use the original jq-web if you:**
- Only target browsers/Node.js (not Cloudflare Workers)
- Want smaller bundle sizes (dynamic WASM loading)
- Need the most memory-efficient option for Node.js servers

## Key differences from original jq-web

1. **Static WASM bundling** - The WASM file is imported at build time rather than fetched at runtime
2. **Universal compatibility** - Works in Cloudflare Workers, which doesn't support dynamic WASM fetching
3. **Emscripten web mode** - Built with `ENVIRONMENT="web"` for better compatibility
4. **Simplified API** - One import works everywhere, no environment detection needed

## Installation and use

```bash
npm install jq-web
```

```js
import initJq from 'jq-web';

const jq = await initJq();
const output = jq.json({
a: {
big: {
json: [
'full',
'of',
'important',
'things'
]
}
}
}, '.a.big.json | ["empty", .[1], "useless", .[3]] | join(" ")');
```

The code above returns the string `"empty of useless things"`.

### Webpack issues

#### `fs`
The Emscripten runtime will try to `require` the `fs` module, and if it fails it will resort to an in-memory filesystem (almost no use of that is made of the library, but it is needed somehow). In Browserify there's a default `{}` that corresponds to the `fs` module, but in Webpack you must [declare it as an empty module](https://github.com/fiatjaf/jq-web/issues/5#issuecomment-342694955).

#### 404 error when loading `.wasm` files
By default projects compiled with Emscripten look for `.wasm` files in the same directory that the `.js` file is run from. This causes issues when using webpack because name of the `.wasm` file is altered with a hash and can be placed in a different directory. To fix this problem you can use the [copy-webpack-plugin](https://github.com/webpack-contrib/copy-webpack-plugin) to copy the `jq.wasm` file to the same directory that the webpack bundle is placed.

## Reference

`jq-web` exports a promise that resolves to an object with `json` and `raw` methods.

`jq.json(, ) ` will take a Javascript object, or scalar, whatever, and dump it to JSON, then it will return whatever your filter outputs and try to convert that into a JS object.

`jq.raw(, , ) ` will take a string that will be passed as it is to jq (like if you were doing `echo '' | jq ` on the command line) then return a string with the raw STDOUT response.

## Build

### Option 1: Using Docker (Recommended)
```bash
./docker-make.sh # Builds everything (equivalent to 'make all')
./docker-make.sh clean # Cleans build artifacts
./docker-make.sh test # Runs tests
```

### Option 2: Local Build
1. Install Emscripten. There have been several API changes over time; version 3.1.31
is known to work.
2. Clone this repository, and `cd` into it.
3. `make`
* This may take a while if you have never run Emscripten before.

## Test
A handful of tests exist in `test.js`. These are a good place to start when verifying a build.
To run them, do `make test`.

You can test browser functionality by running:
`./node_modules/live-server/live-server.js --open="index.html"`.