1 files changed, 46 insertions, 0 deletions
diff --git a/cli/tests/unit/fetch_test.ts b/cli/tests/unit/fetch_test.ts
index c2224083d..cf7510ea2 100644
--- a/cli/tests/unit/fetch_test.ts
+++ b/cli/tests/unit/fetch_test.ts
@@ -1149,3 +1149,49 @@ unitTest({}, function fetchWritableRespProps(): void {
   assertEquals(original.status, new_.status);
   assertEquals(new_.headers.get("x-deno"), "foo");
 });
+
+function returnHostHeaderServer(addr: string): Deno.Listener {
+  const [hostname, port] = addr.split(":");
+  const listener = Deno.listen({
+    hostname,
+    port: Number(port),
+  }) as Deno.Listener;
+
+  listener.accept().then(async (conn: Deno.Conn) => {
+    const httpConn = Deno.serveHttp(conn);
+
+    await httpConn.nextRequest()
+      .then(async (requestEvent: Deno.RequestEvent | null) => {
+        const hostHeader = requestEvent?.request.headers.get("Host");
+        const headersToReturn = hostHeader ? { "Host": hostHeader } : undefined;
+
+        await requestEvent?.respondWith(
+          new Response("", {
+            status: 200,
+            headers: headersToReturn,
+          }),
+        );
+      });
+
+    httpConn.close();
+  });
+
+  return listener;
+}
+
+unitTest(
+  { perms: { net: true } },
+  async function fetchFilterOutCustomHostHeader(): Promise<
+    void
+  > {
+    const addr = "127.0.0.1:4502";
+    const listener = returnHostHeaderServer(addr);
+    const response = await fetch(`http://${addr}/`, {
+      headers: { "Host": "example.com" },
+    });
+    await response.text();
+    listener.close();
+
+    assertEquals(response.headers.get("Host"), addr);
+  },
+);