d837abe5e6
<!-- CURSOR_SUMMARY --> > [!NOTE] > Broaden injection to extensionless and .html routes, gate by Content-Type, and conditionally strip caching/compression headers only when injecting. > > - **Proxy HTML injection**: > - Update `needsInjection(pathname)` to inject for routes without extensions and `.html` files (e.g., `/`, `/foo`, `/foo/bar`, `*.html`). > - Only request uncompressed content and remove `if-none-match` when `needsInjection(target.pathname)` is true. > - During upstream response, inject only if `Content-Type` includes `text/html`; otherwise pass through without modification. > > <sup>Written by [Cursor Bugbot](https://cursor.com/dashboard?tab=bugbot) for commit 2986ceccea64e7881a2197a2a0b202216f21d27d. This will update automatically on new commits. Configure [here](https://cursor.com/dashboard?tab=bugbot).</sup> <!-- /CURSOR_SUMMARY -->
291 lines
8.8 KiB
JavaScript
291 lines
8.8 KiB
JavaScript
/**
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* proxy.js – zero-dependency worker-based HTTP/WS forwarder
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*/
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const { parentPort, workerData } = require("worker_threads");
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const http = require("http");
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const https = require("https");
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const { URL } = require("url");
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const fs = require("fs");
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const path = require("path");
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/* ──────────────────────────── worker code ─────────────────────────────── */
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const LISTEN_HOST = "localhost";
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const LISTEN_PORT = workerData.port;
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let rememberedOrigin = null; // e.g. "http://localhost:5173"
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/* ---------- pre-configure rememberedOrigin from workerData ------- */
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{
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const fixed = workerData?.targetOrigin;
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if (fixed) {
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try {
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rememberedOrigin = new URL(fixed).origin;
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parentPort?.postMessage(
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`[proxy-worker] fixed upstream: ${rememberedOrigin}`,
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);
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} catch {
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throw new Error(
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`Invalid target origin "${fixed}". Must be absolute http/https URL.`,
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);
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}
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}
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}
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/* ---------- optional resources for HTML injection ---------------------- */
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let stacktraceJsContent = null;
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let dyadShimContent = null;
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let dyadComponentSelectorClientContent = null;
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try {
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const stackTraceLibPath = path.join(
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__dirname,
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"..",
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"node_modules",
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"stacktrace-js",
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"dist",
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"stacktrace.min.js",
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);
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stacktraceJsContent = fs.readFileSync(stackTraceLibPath, "utf-8");
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parentPort?.postMessage("[proxy-worker] stacktrace.js loaded.");
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} catch (error) {
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parentPort?.postMessage(
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`[proxy-worker] Failed to read stacktrace.js: ${error.message}`,
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);
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}
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try {
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const dyadShimPath = path.join(__dirname, "dyad-shim.js");
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dyadShimContent = fs.readFileSync(dyadShimPath, "utf-8");
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parentPort?.postMessage("[proxy-worker] dyad-shim.js loaded.");
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} catch (error) {
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parentPort?.postMessage(
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`[proxy-worker] Failed to read dyad-shim.js: ${error.message}`,
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);
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}
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try {
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const dyadComponentSelectorClientPath = path.join(
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__dirname,
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"dyad-component-selector-client.js",
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);
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dyadComponentSelectorClientContent = fs.readFileSync(
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dyadComponentSelectorClientPath,
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"utf-8",
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);
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parentPort?.postMessage(
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"[proxy-worker] dyad-component-selector-client.js loaded.",
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);
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} catch (error) {
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parentPort?.postMessage(
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`[proxy-worker] Failed to read dyad-component-selector-client.js: ${error.message}`,
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);
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}
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/* ---------------------- helper: need to inject? ------------------------ */
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function needsInjection(pathname) {
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// Inject for routes without a file extension (e.g., "/foo", "/foo/bar", "/")
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const ext = path.extname(pathname).toLowerCase();
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return ext === "" || ext === ".html";
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}
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function injectHTML(buf) {
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let txt = buf.toString("utf8");
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// These are strings that were used since the first version of the dyad shim.
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// If the dyad shim is used from legacy apps which came pre-baked with the shim
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// as a vite plugin, then do not inject the shim twice to avoid weird behaviors.
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const legacyAppWithShim =
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txt.includes("window-error") && txt.includes("unhandled-rejection");
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const scripts = [];
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if (!legacyAppWithShim) {
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if (stacktraceJsContent) {
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scripts.push(`<script>${stacktraceJsContent}</script>`);
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} else {
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scripts.push(
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'<script>console.warn("[proxy-worker] stacktrace.js was not injected.");</script>',
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);
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}
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if (dyadShimContent) {
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scripts.push(`<script>${dyadShimContent}</script>`);
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} else {
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scripts.push(
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'<script>console.warn("[proxy-worker] dyad shim was not injected.");</script>',
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);
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}
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}
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if (dyadComponentSelectorClientContent) {
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scripts.push(`<script>${dyadComponentSelectorClientContent}</script>`);
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} else {
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scripts.push(
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'<script>console.warn("[proxy-worker] dyad component selector client was not injected.");</script>',
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);
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}
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const allScripts = scripts.join("\n");
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const headRegex = /<head[^>]*>/i;
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if (headRegex.test(txt)) {
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txt = txt.replace(headRegex, `$&\n${allScripts}`);
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} else {
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txt = allScripts + "\n" + txt;
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parentPort?.postMessage(
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"[proxy-worker] Warning: <head> tag not found – scripts prepended.",
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);
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}
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return Buffer.from(txt, "utf8");
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}
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/* ---------------- helper: build upstream URL from request -------------- */
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function buildTargetURL(clientReq) {
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if (!rememberedOrigin) throw new Error("No upstream configured.");
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// Forward to the remembered origin keeping path & query
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return new URL(clientReq.url, rememberedOrigin);
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}
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/* ----------------------------------------------------------------------- */
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/* 1. Plain HTTP request / response */
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/* ----------------------------------------------------------------------- */
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const server = http.createServer((clientReq, clientRes) => {
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let target;
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try {
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target = buildTargetURL(clientReq);
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} catch (err) {
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clientRes.writeHead(400, { "content-type": "text/plain" });
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return void clientRes.end("Bad request: " + err.message);
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}
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const isTLS = target.protocol === "https:";
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const lib = isTLS ? https : http;
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/* Copy request headers but rewrite Host / Origin / Referer */
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const headers = { ...clientReq.headers, host: target.host };
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if (headers.origin) headers.origin = target.origin;
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if (headers.referer) {
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try {
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const ref = new URL(headers.referer);
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headers.referer = target.origin + ref.pathname + ref.search;
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} catch {
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delete headers.referer;
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}
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}
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if (needsInjection(target.pathname)) {
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// Request uncompressed content from upstream
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delete headers["accept-encoding"];
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// Avoid getting cached resources.
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delete headers["if-none-match"];
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}
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const upOpts = {
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protocol: target.protocol,
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hostname: target.hostname,
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port: target.port || (isTLS ? 443 : 80),
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path: target.pathname + target.search,
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method: clientReq.method,
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headers,
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};
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const upReq = lib.request(upOpts, (upRes) => {
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const wantsInjection = needsInjection(target.pathname);
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// Only inject when upstream indicates HTML content
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const contentTypeHeader = upRes.headers["content-type"];
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const contentType = Array.isArray(contentTypeHeader)
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? contentTypeHeader[0]
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: contentTypeHeader || "";
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const isHtml =
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typeof contentType === "string" &&
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contentType.toLowerCase().includes("text/html");
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const inject = wantsInjection && isHtml;
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if (!inject) {
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clientRes.writeHead(upRes.statusCode, upRes.headers);
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return void upRes.pipe(clientRes);
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}
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const chunks = [];
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upRes.on("data", (c) => chunks.push(c));
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upRes.on("end", () => {
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try {
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const merged = Buffer.concat(chunks);
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const patched = injectHTML(merged);
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const hdrs = {
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...upRes.headers,
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"content-length": Buffer.byteLength(patched),
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};
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// If we injected content, it's no longer encoded in the original way
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delete hdrs["content-encoding"];
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// Also, remove ETag as content has changed
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delete hdrs["etag"];
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clientRes.writeHead(upRes.statusCode, hdrs);
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clientRes.end(patched);
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} catch (e) {
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clientRes.writeHead(500, { "content-type": "text/plain" });
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clientRes.end("Injection failed: " + e.message);
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}
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});
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});
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clientReq.pipe(upReq);
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upReq.on("error", (e) => {
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clientRes.writeHead(502, { "content-type": "text/plain" });
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clientRes.end("Upstream error: " + e.message);
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});
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});
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/* ----------------------------------------------------------------------- */
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/* 2. WebSocket / generic Upgrade tunnelling */
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/* ----------------------------------------------------------------------- */
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server.on("upgrade", (req, socket, _head) => {
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let target;
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try {
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target = buildTargetURL(req);
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} catch (err) {
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socket.write("HTTP/1.1 400 Bad Request\r\n\r\n" + err.message);
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return socket.destroy();
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}
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const isTLS = target.protocol === "https:";
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const headers = { ...req.headers, host: target.host };
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if (headers.origin) headers.origin = target.origin;
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const upReq = (isTLS ? https : http).request({
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protocol: target.protocol,
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hostname: target.hostname,
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port: target.port || (isTLS ? 443 : 80),
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path: target.pathname + target.search,
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method: "GET",
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headers,
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});
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upReq.on("upgrade", (upRes, upSocket, upHead) => {
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socket.write(
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"HTTP/1.1 101 Switching Protocols\r\n" +
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Object.entries(upRes.headers)
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.map(([k, v]) => `${k}: ${v}`)
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.join("\r\n") +
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"\r\n\r\n",
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);
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if (upHead && upHead.length) socket.write(upHead);
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upSocket.pipe(socket).pipe(upSocket);
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});
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upReq.on("error", () => socket.destroy());
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upReq.end();
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});
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/* ----------------------------------------------------------------------- */
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server.listen(LISTEN_PORT, LISTEN_HOST, () => {
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parentPort?.postMessage(
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`proxy-server-start url=http://${LISTEN_HOST}:${LISTEN_PORT}`,
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);
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});
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