Repro / mock request with incoming request.cf properties

test/request-with-IncomingRequestCfProperties.spec.ts

@@ -0,0 +1,49 @@
+import { Miniflare } from "miniflare";
+
+// PASSES
+test("set `cf` in RequestInit", () => {
+  const request = new Request("http://localhost:8787", {
+    cf: { regionCode: "CA" } as IncomingRequestCfProperties,
+  });
+  expect(request.cf?.regionCode).toBe("CA");
+});
+
+// FAILS
+test("set `cf` via Miniflare#metaProvider", async () => {
+  async function handleRequest(request: Request) {
+    // undefined
+    expect(request.cf?.regionCode).toBe("CA");
+    return new Response("OK");
+  }
+
+  const mf = new Miniflare({
+    script: `
+      export default {
+        fetch: handleRequest,
+      }
+    `,
+    globals: {
+      handleRequest,
+    },
+    modules: true,
+    /**
+     * > Added a metaProvider option that allows you fetch metadata for an incoming Request
+     * > https://github.com/cloudflare/miniflare/releases/tag/v2.0.0
+     *
+     * https://github.com/cloudflare/miniflare/issues/61#issuecomment-952817275
+     * https://github.com/cloudflare/miniflare/commit/b7ddbb36f0a1998519a4ac179e1a609cad7e75be#diff-a732a2a999ca2078de283e7dab7fe68fef00ec14cda5e89c1fb8d3a26518fc2eR31
+     */
+    async metaProvider(_req: Request) {
+      return {
+        // forwardedProto: req.headers.get("X-Forwarded-Proto"),
+        // realIp: req.headers.get("X-Forwarded-For"),
+        cf: {
+          regionCode: "CA",
+        },
+      };
+    },
+  });
+
+  await mf.dispatchFetch("http://localhost:8787/");
+  expect.assertions(1);
+});