Vencord/src/webpack/patchWebpack.ts

353 lines
15 KiB
TypeScript

/*
* Vencord, a modification for Discord's desktop app
* Copyright (c) 2022 Vendicated and contributors
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <https://www.gnu.org/licenses/>.
*/
import { WEBPACK_CHUNK } from "@utils/constants";
import { Logger } from "@utils/Logger";
import { canonicalizeMatch, canonicalizeReplacement } from "@utils/patches";
import { PatchReplacement } from "@utils/types";
import { WebpackInstance } from "discord-types/other";
import { traceFunction } from "../debug/Tracer";
import { patches } from "../plugins";
import { _initWebpack, beforeInitListeners, factoryListeners, moduleListeners, subscriptions, wreq } from ".";
const logger = new Logger("WebpackInterceptor", "#8caaee");
const initCallbackRegex = canonicalizeMatch(/{return \i\(".+?"\)}/);
let webpackChunk: any[];
// Patch the window webpack chunk setter to monkey patch the push method before any chunks are pushed
// This way we can patch the factory of everything being pushed to the modules array
Object.defineProperty(window, WEBPACK_CHUNK, {
configurable: true,
get: () => webpackChunk,
set: v => {
if (v?.push) {
if (!v.push.$$vencordOriginal) {
logger.info(`Patching ${WEBPACK_CHUNK}.push`);
patchPush(v);
// @ts-ignore
delete window[WEBPACK_CHUNK];
window[WEBPACK_CHUNK] = v;
}
}
webpackChunk = v;
}
});
// wreq.O is the webpack onChunksLoaded function
// Discord uses it to await for all the chunks to be loaded before initializing the app
// We monkey patch it to also monkey patch the initialize app callback to get immediate access to the webpack require and run our listeners before doing it
Object.defineProperty(Function.prototype, "O", {
configurable: true,
set(onChunksLoaded: any) {
// When using react devtools or other extensions, or even when discord loads the sentry, we may also catch their webpack here.
// This ensures we actually got the right one
// this.e (wreq.e) is the method for loading a chunk, and only the main webpack has it
if (new Error().stack?.includes("discord.com") && String(this.e).includes("Promise.all")) {
logger.info("Found main WebpackRequire.onChunksLoaded");
delete (Function.prototype as any).O;
const originalOnChunksLoaded = onChunksLoaded;
onChunksLoaded = function (this: unknown, result: any, chunkIds: string[], callback: () => any, priority: number) {
if (callback != null && initCallbackRegex.test(callback.toString())) {
Object.defineProperty(this, "O", {
value: originalOnChunksLoaded,
configurable: true
});
const wreq = this as WebpackInstance;
const originalCallback = callback;
callback = function (this: unknown) {
logger.info("Patched initialize app callback invoked, initializing our internal references to WebpackRequire and running beforeInitListeners");
_initWebpack(wreq);
for (const beforeInitListener of beforeInitListeners) {
beforeInitListener(wreq);
}
originalCallback.apply(this, arguments as any);
};
callback.toString = originalCallback.toString.bind(originalCallback);
arguments[2] = callback;
}
originalOnChunksLoaded.apply(this, arguments as any);
};
onChunksLoaded.toString = originalOnChunksLoaded.toString.bind(originalOnChunksLoaded);
}
Object.defineProperty(this, "O", {
value: onChunksLoaded,
configurable: true
});
}
});
// wreq.m is the webpack module factory.
// normally, this is populated via webpackGlobal.push, which we patch below.
// However, Discord has their .m prepopulated.
// Thus, we use this hack to immediately access their wreq.m and patch all already existing factories
//
// Update: Discord now has TWO webpack instances. Their normal one and sentry
// Sentry does not push chunks to the global at all, so this same patch now also handles their sentry modules
Object.defineProperty(Function.prototype, "m", {
configurable: true,
set(v: any) {
// When using react devtools or other extensions, we may also catch their webpack here.
// This ensures we actually got the right one
const error = new Error();
if (error.stack?.includes("discord.com")) {
logger.info("Found Webpack module factory", error.stack.match(/\/assets\/(.+?\.js)/)?.[1] ?? "");
patchFactories(v);
}
Object.defineProperty(this, "m", {
value: v,
configurable: true
});
}
});
function patchPush(webpackGlobal: any) {
function handlePush(chunk: any) {
try {
patchFactories(chunk[1]);
} catch (err) {
logger.error("Error in handlePush", err);
}
return handlePush.$$vencordOriginal.call(webpackGlobal, chunk);
}
handlePush.$$vencordOriginal = webpackGlobal.push;
handlePush.toString = handlePush.$$vencordOriginal.toString.bind(handlePush.$$vencordOriginal);
// Webpack overwrites .push with its own push like so: `d.push = n.bind(null, d.push.bind(d));`
// it wraps the old push (`d.push.bind(d)`). this old push is in this case our handlePush.
// If we then repatched the new push, we would end up with recursive patching, which leads to our patches
// being applied multiple times.
// Thus, override bind to use the original push
handlePush.bind = (...args: unknown[]) => handlePush.$$vencordOriginal.bind(...args);
Object.defineProperty(webpackGlobal, "push", {
configurable: true,
get: () => handlePush,
set(v) {
handlePush.$$vencordOriginal = v;
}
});
}
let webpackNotInitializedLogged = false;
function patchFactories(factories: Record<string, (module: any, exports: any, require: WebpackInstance) => void>) {
for (const id in factories) {
let mod = factories[id];
const originalMod = mod;
const patchedBy = new Set();
const factory = factories[id] = function (module: any, exports: any, require: WebpackInstance) {
if (wreq == null && IS_DEV) {
if (!webpackNotInitializedLogged) {
webpackNotInitializedLogged = true;
logger.error("WebpackRequire was not initialized, running modules without patches instead.");
}
return void originalMod(module, exports, require);
}
try {
mod(module, exports, require);
} catch (err) {
// Just rethrow discord errors
if (mod === originalMod) throw err;
logger.error("Error in patched module", err);
return void originalMod(module, exports, require);
}
exports = module.exports;
if (!exports) return;
// There are (at the time of writing) 11 modules exporting the window
// Make these non enumerable to improve webpack search performance
if (exports === window && require.c) {
Object.defineProperty(require.c, id, {
value: require.c[id],
enumerable: false,
configurable: true,
writable: true
});
return;
}
for (const callback of moduleListeners) {
try {
callback(exports, id);
} catch (err) {
logger.error("Error in Webpack module listener:\n", err, callback);
}
}
for (const [filter, callback] of subscriptions) {
try {
if (filter(exports)) {
subscriptions.delete(filter);
callback(exports, id);
} else if (exports.default && filter(exports.default)) {
subscriptions.delete(filter);
callback(exports.default, id);
}
} catch (err) {
logger.error("Error while firing callback for Webpack subscription:\n", err, filter, callback);
}
}
} as any as { toString: () => string, original: any, (...args: any[]): void; };
factory.toString = originalMod.toString.bind(originalMod);
factory.original = originalMod;
for (const factoryListener of factoryListeners) {
try {
factoryListener(originalMod);
} catch (err) {
logger.error("Error in Webpack factory listener:\n", err, factoryListener);
}
}
// Discords Webpack chunks for some ungodly reason contain random
// newlines. Cyn recommended this workaround and it seems to work fine,
// however this could potentially break code, so if anything goes weird,
// this is probably why.
// Additionally, `[actual newline]` is one less char than "\n", so if Discord
// ever targets newer browsers, the minifier could potentially use this trick and
// cause issues.
//
// 0, prefix is to turn it into an expression: 0,function(){} would be invalid syntax without the 0,
let code: string = "0," + mod.toString().replaceAll("\n", "");
for (let i = 0; i < patches.length; i++) {
const patch = patches[i];
if (patch.predicate && !patch.predicate()) continue;
if (!code.includes(patch.find)) continue;
patchedBy.add(patch.plugin);
const executePatch = traceFunction(`patch by ${patch.plugin}`, (match: string | RegExp, replace: string) => code.replace(match, replace));
const previousMod = mod;
const previousCode = code;
// We change all patch.replacement to array in plugins/index
for (const replacement of patch.replacement as PatchReplacement[]) {
if (replacement.predicate && !replacement.predicate()) continue;
const lastMod = mod;
const lastCode = code;
canonicalizeReplacement(replacement, patch.plugin);
try {
const newCode = executePatch(replacement.match, replacement.replace as string);
if (newCode === code) {
if (!patch.noWarn) {
logger.warn(`Patch by ${patch.plugin} had no effect (Module id is ${id}): ${replacement.match}`);
if (IS_DEV) {
logger.debug("Function Source:\n", code);
}
}
if (patch.group) {
logger.warn(`Undoing patch group ${patch.find} by ${patch.plugin} because replacement ${replacement.match} had no effect`);
mod = previousMod;
code = previousCode;
patchedBy.delete(patch.plugin);
break;
}
continue;
}
code = newCode;
mod = (0, eval)(`// Webpack Module ${id} - Patched by ${[...patchedBy].join(", ")}\n${newCode}\n//# sourceURL=WebpackModule${id}`);
} catch (err) {
logger.error(`Patch by ${patch.plugin} errored (Module id is ${id}): ${replacement.match}\n`, err);
if (IS_DEV) {
const changeSize = code.length - lastCode.length;
const match = lastCode.match(replacement.match)!;
// Use 200 surrounding characters of context
const start = Math.max(0, match.index! - 200);
const end = Math.min(lastCode.length, match.index! + match[0].length + 200);
// (changeSize may be negative)
const endPatched = end + changeSize;
const context = lastCode.slice(start, end);
const patchedContext = code.slice(start, endPatched);
// inline require to avoid including it in !IS_DEV builds
const diff = (require("diff") as typeof import("diff")).diffWordsWithSpace(context, patchedContext);
let fmt = "%c %s ";
const elements = [] as string[];
for (const d of diff) {
const color = d.removed
? "red"
: d.added
? "lime"
: "grey";
fmt += "%c%s";
elements.push("color:" + color, d.value);
}
logger.errorCustomFmt(...Logger.makeTitle("white", "Before"), context);
logger.errorCustomFmt(...Logger.makeTitle("white", "After"), patchedContext);
const [titleFmt, ...titleElements] = Logger.makeTitle("white", "Diff");
logger.errorCustomFmt(titleFmt + fmt, ...titleElements, ...elements);
}
patchedBy.delete(patch.plugin);
if (patch.group) {
logger.warn(`Undoing patch group ${patch.find} by ${patch.plugin} because replacement ${replacement.match} errored`);
mod = previousMod;
code = previousCode;
break;
}
mod = lastMod;
code = lastCode;
}
}
if (!patch.all) patches.splice(i--, 1);
}
}
}