HLCC

The client mod agnostic tool to build Discord snippets, powered by swc

Warning | This repo is a Discord modding project. On the 27th September 2022, Discord switched part of their build pipeline out.
This fundamentally broke many parts of modding, and hence this project is discontinued.
For more info see https://cumcord.com/an-exercise-in-futility
EVERYTHING HERE IS NOW LICENSED UNDER THE UNLICENSE AS OF 2022-10-19

Installation

npm i -D hlcc or pnpm i -D hlcc

Basic Usage

Your code should be wrapped in hlccInject, as such:

hlccInject([], () => {
    console.log("Hello, World! from HLCC")
});

Any instance of hlccInject is transformed.

Now simply build your code: npm exec hlcc -- mycode.js output.js or pnpm hlcc mycode.js output.js

Reference

hlccInject(ModuleFind[], Function)

hlccInject takes two arguments: a list of module finds, and a callback function. It will find the modules passed (see below), and make them available to your code.

The args of your function should correspond to the module finds: the first module find will be the first arg passed etc.

hlccAll()

A module find that just returns the raw modules object.

hlccByProps(...string[], number?)

A module find that finds the module with the given props.

All arguments must be strings, except optionally the last argument, which may be a number - if multiple modules match this specifies which to grab (index).

If left blank it is effectively 0.

hlccByProps("commonProp", 5); // 6th match
hlccByProps("commonProp"); // 1st match

hlccByDName(string, number?)

A module find that finds the module with the given display name, useful for React components.

It, unlike hlccByProps, does not return the default export of the module - this is because doing that would make patching impossible.

For indexing behaviour, see hlccByProps above.

React.createElement(hlccByDName("Header").default);
hlccByDName("Header", 1); // i actually wanted the 2nd header module

hlccByPredicate((any) => bool, number?)

Finds a module by a test function. Optionally indexes - see above.

hlccByPredicate(m => Array.isArray(m?._Messages) /* , 1 */);

As an API

HLCC exports an (async) function to run its transform (and optionally / by default minify).

import hlcc from "hlcc";
// hlcc: (input: string, shouldMinify?: boolean) => Promise<string>
const code = "hlccInject([], () => {});";
const transformed = await hlcc(code); // see below example for sample output
const unminified = await hlcc(code, false); // should be pretty self-explanatory

A full example (as a build tool)

hlcc example.js compiled.js

This is an example input code to HLCC.

hlccInject(
  [
    hlccByProps("_dispatcher", 50), // 51st Flux store found
    hlccByProps("open"), // first module with `open`
    hlccByDName("Header", 1), // 2nd `Header` component
    hlccAll(),
  ],
  (store, settings, Header, mods) => {
    if (Object.keys(mods).length % 2 === 0)
      console.log("Even number of modules");
    else console.log("Odd number of modules");

    console.log(store, settings, Header);
  }
);

Here is the generated code - with --nominify flag and run through prettier:

{
  const _w = webpackChunkdiscord_app;
  let store, settings, Header, mods;
  _w.push([
    [Symbol()],
    {},
    (e) => {
      mods = e.c;
      let _i0 = 0,
        _i2 = 0;
      for (const k in e.c) {
        const m = e.c[k].exports;
        const mDef = m?.default && m.__esModule ? m.default : m;
        if (mDef?._dispatcher && _i0++ === 50) store = mDef;
        if (mDef?.open && !settings) settings = mDef;
        if (mDef?.displayName === "Header" && _i2++ === 1) Header = m;
      }
    },
  ]);
  _w.pop();
  if (Object.keys(mods).length % 2 === 0) console.log("Even number of modules");
  else console.log("Odd number of modules");
  console.log(store, settings, Header);
  void 0;
}

Here is the actual output as HLCC will output it:

{const a=webpackChunkdiscord_app;let b,c,d,e;a.push([[Symbol()],{},a=>{e=a.c;let f=0,g=0;for(const h in a.c){const i=a.c[h].exports;const j=i?.default&&i.__esModule?i.default:i;if(j?._dispatcher&&(f++)===50)b=j;if(j?.open&&!c)c=j;if(j?.displayName==="Header"&&(g++)===1)d=i}}]);a.pop();if(Object.keys(e).length%2===0)console.log("Even number of modules");else console.log("Odd number of modules");console.log(b,c,d);void 0}

A minimal (ish!) annotated example

hlccInject(
  [
    hlccAll(),
    hlccByDName("Header"),
    hlccByProps("_dispatcher", 50),
  ],
  (mods, Header, store) => {
    console.log(Object.keys(mods).length, Head, store);
  }
);

{
  // help out minifiers in compressing the compiled snippets
  const _w = webpackChunkdiscord_app;

  // initialise variables - these are the "args" you asked for in your callback
  let mods, header, store;

  // inject into webpack
  _w.push([
    [Symbol()],
    {},
    (e) => {
      // e.c now contains the raw module list
      // mods (1st find) wants the raw modules
      mods = e.c;
      // the module find at index 2 (3rd one) uses indexing instead of first
      // so store the counter here
      let _i2 = 0;

      // begin looping through modules
      for (const k in e.c) {
        // get the raw module
        const m = e.c[k].exports;
        // if the module has a default export, use that instead (except for display names)
        const mDef = m?.default && m.__esModule ? m.default : m;
        // match default.displayName, and only match once (&& !header)
        if (mDef?.displayName === "Header" && !header) header = m;
        // match default._dispatcher, and only if index is 50 (also increment)
        if (mDef?._dispatcher && _i2++ === 50) store = mDef;
      }
    },
  ]);

  // dont memory leak
  _w.pop();

  // this is the code the user passed in the callback! Here just logs
  console.log(Object.keys(mods).length, header, store);

  // prevents the value of the last expr being printed when you paste into devtools
  void 0;
}