🤖 Merge PR DefinitelyTyped#74687 [@types/koa]: add custom AsyncLocalStorage support to Application constructor by @kshitijanurag

Author: kshitijanurag

types/koa/index.d.ts

@@ -465,7 +465,7 @@ declare class Application<
      * @param {number} [options.subdomainOffset] Subdomain offset
      * @param {string} [options.proxyIpHeader] Proxy IP header, defaults to X-Forwarded-For
      * @param {number} [options.maxIpsCount] Max IPs read from proxy IP header, default to 0 (means infinity)
-     * @param {boolean} [options.asyncLocalStorage] Enable AsyncLocalStorage
+     * @param {boolean|AsyncLocalStorage} [options.asyncLocalStorage]  Pass `true` or an instance of `AsyncLocalStorage` to enable async local storage
      */
     constructor(options?: {
         env?: string | undefined;
@@ -474,7 +474,7 @@ declare class Application<
         subdomainOffset?: number | undefined;
         proxyIpHeader?: string | undefined;
         maxIpsCount?: number | undefined;
-        asyncLocalStorage?: boolean | undefined;
+        asyncLocalStorage?: boolean | AsyncLocalStorage<ContextT> | undefined;
     });
 
     /**

types/koa/test/constructor.ts

@@ -1,19 +1,41 @@
 import Koa = require("koa");
+import assert from "node:assert/strict";
+import { AsyncLocalStorage } from "node:async_hooks";
 
-const app = new Koa({
-    env: "abc",
-    keys: ["im a newer secret", "i like turtle"],
-    proxy: true,
-    subdomainOffset: 2,
-    proxyIpHeader: "XYZ-Forwarded-For",
-    maxIpsCount: 2,
-    asyncLocalStorage: true,
-});
+{
+    const app = new Koa({
+        env: "abc",
+        keys: ["im a newer secret", "i like turtle"],
+        proxy: true,
+        subdomainOffset: 2,
+        proxyIpHeader: "XYZ-Forwarded-For",
+        maxIpsCount: 2,
+        asyncLocalStorage: true,
+    });
 
-app.use(ctx => {
-    ctx.body = "Hello World";
-});
+    app.use(ctx => {
+        ctx.body = "Hello World";
+    });
 
-app.listen(3000);
+    app.listen(3000);
+}
 
-const server = app.listen();
+{
+    const asyncLocalStorage = new AsyncLocalStorage<Koa.Context>();
+    const app = new Koa({ asyncLocalStorage });
+
+    assert(app.currentContext === undefined);
+
+    app.use(async (ctx, next) => {
+        callSomeFunction();
+        ctx.body = "ok";
+        await next();
+    });
+
+    function callSomeFunction() {
+        const ctx = asyncLocalStorage.getStore();
+        assert(ctx === app.currentContext);
+    }
+
+    app.listen();
+}