From 554686744901376f005d139f983d783668e402ff Mon Sep 17 00:00:00 2001
From: Brandon Wolfgang <developer@brandonwolfgang.com>
Date: Wed, 21 Oct 2026 19:30:31 -0500
Subject: [PATCH] =?UTF-8?q?test:=20add=20validation=20tests=20for=20POST?=
 =?UTF-8?q?=20/echo=20-=20Test=20successful=20echo=20responses=20for=20val?=
 =?UTF-8?q?id=20messages=20-=20Verify=20empty=20messages=20are=20rejected?=
 =?UTF-8?q?=20with=20HTTP=20400=20-=20Validate=20request=20bodies=20using?=
 =?UTF-8?q?=20a=20Zod=20schema=20with=20a=201=E2=80=93500=20character=20li?=
 =?UTF-8?q?mit=20-=20Return=20a=20consistent=20error=20response=20for=20in?=
 =?UTF-8?q?valid=20request=20bodies?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

---
 src/server.test.ts | 30 ++++++++++++++++++++++++++++++
 src/server.ts      | 19 +++++++++++++++++++
 2 files changed, 49 insertions(+)

diff --git a/src/server.test.ts b/src/server.test.ts
index cd48ff4..8aae978 100644
--- a/src/server.test.ts
+++ b/src/server.test.ts
@@ -37,6 +37,36 @@ describe("API endpoints", () => {
     });
   });
 
+  it("POST /echo returns the validated message", async () => {
+    const response = await app.inject({
+      method: "POST",
+      url: "/echo",
+      payload: {
+        message: "Hello, world!",
+      },
+    });
+
+    assert.equal(response.statusCode, 200);
+    assert.deepEqual(response.json(), {
+      message: "Hello, world!",
+    });
+  });
+
+  it("POST /echo rejects an empty message", async () => {
+    const response = await app.inject({
+      method: "POST",
+      url: "/echo",
+      payload: {
+        message: "",
+      },
+    });
+
+    assert.equal(response.statusCode, 400);
+    assert.deepEqual(response.json(), {
+      error: "Invalid request body",
+    });
+  });
+
   it("returns 404 for an unknown endpoint", async () => {
     const response = await app.inject({
       method: "GET",
diff --git a/src/server.ts b/src/server.ts
index 4730318..3b5118a 100644
--- a/src/server.ts
+++ b/src/server.ts
@@ -1,4 +1,5 @@
 import Fastify from "fastify";
+import { z } from "zod";
 
 export const buildApp = () => {
   const app = Fastify({
@@ -16,6 +17,24 @@ export const buildApp = () => {
     },
   }));
 
+  app.post("/echo", async (request, reply) => {
+    const schema = z.object({
+      message: z.string().min(1).max(500),
+    });
+
+    const result = schema.safeParse(request.body);
+
+    if (!result.success) {
+      return reply.code(400).send({
+        error: "Invalid request body",
+      });
+    }
+
+    return {
+      message: result.data.message,
+    };
+  });
+
   return app;
 };