Utility for intercepting and patching Webpack chunks in UserScripts
Tento skript by neměl být instalován přímo. Jedná se o knihovnu, kterou by měly jiné skripty využívat pomocí meta příkazu // @require https://update.greasyfork.org/scripts/588910/1889690/Webpack%20Patcher%20Library.js
// ==UserScript==
// @name Webpack Patcher Library
// @namespace webasm
// @version 0.3
// @description Utility for intercepting and patching Webpack chunks in UserScripts
// @author webasm
// @grant unsafeWindow
// ==/UserScript==
(function() {
'use strict';
const targetWindow =
typeof unsafeWindow !== 'undefined' ? unsafeWindow : window;
if (targetWindow.WebpackPatcher) return;
// ============================================================
// ModulePatch
// ============================================================
class ModulePatch {
constructor(idOrKeyword, context = null) {
if (typeof idOrKeyword === 'number') {
this._id = idOrKeyword;
this._keyword = null;
} else {
this._id = null;
this._keyword =
Array.isArray(idOrKeyword)
? idOrKeyword
: [idOrKeyword];
}
this._context = context;
this._isPatched = false;
}
get id() {
return this._id;
}
get keyword() {
return this._keyword;
}
get context() {
return this._context;
}
get isPatched() {
return this._isPatched;
}
test(moduleId, moduleStr) {
if (this._id !== null) {
return String(moduleId) === String(this._id);
}
if (this._keyword !== null) {
return this._keyword.every(kw => {
if (typeof kw === 'string') {
return moduleStr.includes(kw);
}
if (kw instanceof RegExp) {
return kw.test(moduleStr);
}
return false;
});
}
return false;
}
transformBody(originalBody) {
return originalBody;
}
applyTo(originalModule, matchedId) {
const moduleStr = originalModule.toString();
const match = moduleStr.match(
/^(?:async\s+)?(?:function\*?\s*(?:\w+\s*)?)?\(([^)]*)\)\s*(?:=>)?\s*\{([\s\S]*)\}$/
);
if (!match) {
console.warn(
`[Patch] Regex mismatch for module ${matchedId}. ` +
`It might be an unexpected format. Skipping.`
);
return originalModule;
}
const argsStr = match[1];
const funcBodyStr = match[2];
const args = argsStr
.split(',')
.map(s => s.trim())
.filter(Boolean);
const modifiedBody = this.transformBody(funcBodyStr);
const errorCatchStart = `try { \n`;
const errorCatchEnd =
`\n} catch(err) { ` +
`console.error("[Patch Error] Module ${matchedId}:", err); }`;
try {
const newFunc = new Function(
...args,
errorCatchStart + modifiedBody + errorCatchEnd
);
this._isPatched = true;
return newFunc;
} catch (err) {
console.error(
`[Patch] Syntax Error while building function for module ${matchedId}. ` +
`Falling back to original.`,
err
);
return originalModule;
}
}
}
// ============================================================
// ModulePatchManager
// ============================================================
class ModulePatchManager {
constructor() {
this.patches = [];
}
register(patch) {
this.patches.push(patch);
}
unregister(patch) {
this.patches = this.patches.filter(p => p !== patch);
}
processModules(modules, currentContext = null) {
if (!modules) return;
const pendingPatches = [...this.patches];
for (const patch of pendingPatches) {
if (patch.isPatched) continue;
if (
patch.context !== null &&
patch.context !== currentContext
) {
continue;
}
for (const [moduleId, originalModule] of Object.entries(modules)) {
if (!originalModule) continue;
const moduleStr = originalModule.toString();
if (patch.test(moduleId, moduleStr)) {
try {
const patchedModule =
patch.applyTo(originalModule, moduleId);
modules[moduleId] = patchedModule;
console.log(
`[PatchManager] Successfully patched module: ` +
`${moduleId} (Context: ${currentContext})`
);
if (patch.isPatched) {
this.unregister(patch);
}
} catch (error) {
console.error(
`[PatchManager] Failed to patch module: ${moduleId}`,
error
);
}
break;
}
}
}
}
}
// ============================================================
// WebpackChunkInterceptor
// ============================================================
class WebpackChunkInterceptor {
constructor(
patchManager,
globalVarName,
injectionPayload = null
) {
this.patchManager = patchManager;
this.globalVarName = globalVarName;
this.injectionPayload = injectionPayload;
}
_getChunkIdentifier(chunk) {
try {
return chunk[0][0];
} catch (e) {
return "unknown";
}
}
attach() {
if (this.patchManager.patches.length === 0) return;
const self = this;
const globalName = this.globalVarName;
const hookArray = (arr) => {
if (!arr || arr.__isHooked) return;
Object.defineProperty(arr, '__isHooked', {
value: true,
enumerable: false,
writable: true
});
/*
* Capture the original push method before installing
* the interceptor.
*
* The important part is that the wrapper itself is never
* assigned back to originalPush.
*/
const originalPush = arr.push;
const hookedPush = function(...args) {
try {
args.forEach(chunk => {
if (chunk && chunk[1]) {
const chunkId =
self._getChunkIdentifier(chunk);
self.patchManager.processModules(
chunk[1],
chunkId
);
}
});
} catch (err) {
console.error(
"[Interceptor] Error inside push wrapper:",
err
);
}
/*
* Call the original push directly.
*
* Do not access arr.push here, because arr.push is now
* the hooked function and would recurse into itself.
*/
return originalPush.apply(this, args);
};
/*
* Keep push as a normal writable data property.
*
* This intentionally avoids a getter/setter pair.
*/
Object.defineProperty(arr, 'push', {
value: hookedPush,
writable: true,
configurable: true,
enumerable: true
});
/*
* Process chunks that already exist.
*/
try {
arr.forEach(chunk => {
if (chunk && chunk[1]) {
const chunkId =
self._getChunkIdentifier(chunk);
self.patchManager.processModules(
chunk[1],
chunkId
);
}
});
} catch (err) {
console.error(
"[Interceptor] Error processing existing chunks:",
err
);
}
/*
* Inject the payload after the existing chunks have been
* processed, matching the original behavior.
*/
if (self.injectionPayload) {
try {
hookedPush.call(
arr,
self.injectionPayload
);
} catch (err) {
console.error(
"[Interceptor] Error injecting payload:",
err
);
}
}
};
let existingVal = targetWindow[globalName];
if (
existingVal &&
Array.isArray(existingVal)
) {
hookArray(existingVal);
} else if (
existingVal === undefined
) {
existingVal = [];
hookArray(existingVal);
}
Object.defineProperty(
targetWindow,
globalName,
{
get() {
return existingVal;
},
set(newVal) {
existingVal = newVal;
if (Array.isArray(existingVal)) {
hookArray(existingVal);
}
},
configurable: true
}
);
console.log(
`[Interceptor] Attached webpackChunk Interceptor ` +
`securely to ${globalName}`
);
}
}
// ============================================================
// WebpackInternalCallInterceptor
// ============================================================
class WebpackInternalCallInterceptor {
constructor(
patchManager,
triggerModuleId,
targetFilename
) {
this.patchManager = patchManager;
this.triggerModuleId = triggerModuleId;
this.targetFilename = targetFilename;
}
attach() {
if (
this.patchManager.patches.length === 0
) {
return;
}
const self = this;
const origCall = Function.prototype.call;
Function.prototype.call = function(
thisArg,
...args
) {
const module = args[0];
if (
module &&
String(module.id) ===
String(self.triggerModuleId)
) {
const stack =
new Error().stack || "";
if (
stack.includes(
self.targetFilename
)
) {
try {
const __webpack_require__ =
args[2];
if (
__webpack_require__ &&
__webpack_require__.m
) {
self.patchManager.processModules(
__webpack_require__.m,
self.targetFilename
);
}
} finally {
Function.prototype.call = origCall;
console.log(
`[Interceptor] Unhooked Webpack Internal ` +
`Call Interceptor for ${self.targetFilename}`
);
}
}
}
return origCall.apply(
this,
[thisArg, ...args]
);
};
console.log(
`[Interceptor] Attached Webpack Internal Call ` +
`Interceptor for ${self.targetFilename}`
);
}
}
// ============================================================
// Public API
// ============================================================
targetWindow.WebpackPatcher = {
ModulePatch,
ModulePatchManager,
WebpackChunkInterceptor,
WebpackInternalCallInterceptor
};
})();