feat: support blob responses

src/app.ts

@@ -135,6 +135,15 @@ export function createAppEventHandler(stack: Stack, options: AppOptions) {
           return send(event, val);
         }
 
+        // Blob
+        if (val.arrayBuffer && typeof val.arrayBuffer === "function") {
+          return send(
+            event,
+            Buffer.from(await (val as Blob).arrayBuffer()),
+            val.type
+          );
+        }
+
         // Error
         if (val instanceof Error) {
           throw createError(val);

test/app.test.ts

@@ -10,8 +10,9 @@ import {
   createError,
 } from "../src";
 
-const readableStreamSupported =
-  typeof ReadableStream !== "undefined"; /* Node.js 16 */
+// Node.js 16 limitations
+const readableStreamSupported = typeof ReadableStream !== "undefined";
+const blobSupported = typeof Blob !== "undefined";
 
 describe("app", () => {
   let app: App;
@@ -55,6 +56,21 @@ describe("app", () => {
     }
   });
 
+  it.runIf(blobSupported)("can return Blob directly", async () => {
+    app.use(
+      eventHandler(
+        () =>
+          new Blob(["<h1>Hello World</h1>"], {
+            type: "text/html",
+          })
+      )
+    );
+    const res = await request.get("/");
+
+    expect(res.headers["content-type"]).toBe("text/html");
+    expect(res.text).toBe("<h1>Hello World</h1>");
+  });
+
   it("can return Buffer directly", async () => {
     app.use(eventHandler(() => Buffer.from("<h1>Hello world!</h1>", "utf8")));
     const res = await request.get("/");