feat: set metadata headers on all responses

lib/handler.ts

@@ -6,7 +6,9 @@ import { UrlConfig } from "./types.d.ts";
 import { parseBool, requestLog } from "./util.ts";
 import { sendWebhook } from "./webhook.ts";
 
-export default async function handle(req: Request): Promise<Response> {
+export default async function handle(
+    req: Request,
+): Promise<Response | [Response, Record<string, string>]> {
     const url = new URL(req.url);
 
     // redirect to repo if `GET /`

lib/webhook.ts

@@ -6,7 +6,7 @@ export async function sendWebhook(
     token: string,
     headers: Headers,
     body: string,
-): Promise<Response> {
+): Promise<[Response, Record<string, string>]> {
     const reqLog = requestLog(headers);
     const url = `https://discord.com/api/webhooks/${id}/${token}/github?wait=1`;
 
@@ -54,22 +54,9 @@ export async function sendWebhook(
         await sleep(resetms);
     } while (true);
 
-    // clone response to make headers mutable
-    res = new Response(res.body, res);
-
-    // set metadata headers
-    const meta: Record<string, string> = {
-        "deploy": config.deployId,
-    };
+    // set metadata
+    const meta: Record<string, string> = {};
     if (retries) meta["retries"] = retries.toString();
 
-    setMetadata(res, meta);
-
-    return res;
-}
-
-function setMetadata(res: Response, meta: Record<string, string>): void {
-    for (const [key, value] of Object.entries(meta)) {
-        res.headers.set(`x-webhook-filter-${key}`, value);
-    }
+    return [res, meta];
 }

main.ts

@@ -21,9 +21,16 @@ async function setupLogs(): Promise<void> {
 
 async function handleRequest(req: Request, connInfo: http.ConnInfo): Promise<Response> {
     const reqLog = requestLog(req.headers);
+
     let res: Response;
+    let meta: Record<string, string> | null = null;
     try {
-        res = await handler(req);
+        const webhookResult = await handler(req);
+        if (webhookResult instanceof Response) {
+            res = webhookResult;
+        } else {
+            [res, meta] = webhookResult;
+        }
     } catch (err) {
         if (http.isHttpError(err) && err.expose) {
             reqLog.warning(`http error: ${err.message}`);
@@ -34,6 +41,19 @@ async function handleRequest(req: Request, connInfo: http.ConnInfo): Promise<Res
         }
     }
 
+    // clone response to make headers mutable
+    res = new Response(res.body, res);
+
+    // set metadata headers
+    meta = {
+        "deploy": config.deployId,
+        ...meta,
+    };
+    for (const [key, value] of Object.entries(meta)) {
+        res.headers.set(`x-webhook-filter-${key}`, value);
+    }
+
+    // log request
     const respLen = res.headers.get("content-length") || 0;
     const addr = connInfo.remoteAddr as Deno.NetAddr;
     reqLog.info(