Merge pull request #17 from lifeomic/allow-customizing-error

feat: allow customizing success status codes

src/koa.test.ts

@@ -1,3 +1,6 @@
+import axios from 'axios';
+import Koa = require('koa');
+import bodyParser = require('koa-bodyparser');
 import Router = require('koa-router');
 import { implementSchema } from '.';
 import { withAssumptions } from './meta-schema';
@@ -25,3 +28,56 @@ test('using unsupported methods throws immediately', () => {
     );
   }).toThrowError('Unsupported method detected: OPTIONS /post');
 });
+
+test('setting a 200-level response code overrides the response', async () => {
+  const router = new Router();
+  implementSchema(
+    withAssumptions({
+      Endpoints: {
+        'DELETE /post/:id': {
+          Name: 'deletePost',
+          Response: {},
+        },
+        'POST /posts': {
+          Name: 'createPost',
+          Response: {},
+        },
+      },
+    }),
+    {
+      on: router,
+      parse: () => null as any,
+      implementation: {
+        'DELETE /post/:id': (ctx) => {
+          ctx.response.status = 204;
+          return {};
+        },
+        'POST /posts': (ctx) => {
+          ctx.response.status = 301;
+          return {};
+        },
+      },
+    },
+  );
+
+  const server = new Koa()
+    .use(bodyParser())
+    .use(router.routes())
+    .use(router.allowedMethods())
+    .listen();
+
+  const { port } = server.address() as any;
+
+  const client = axios.create({
+    baseURL: `http://localhost:${port}`,
+    validateStatus: () => true,
+  });
+
+  const deleteRes = await client.delete('/post/bogus');
+  expect(deleteRes.status).toStrictEqual(204);
+
+  const createRes = await client.post('/posts');
+  expect(createRes.status).toStrictEqual(200);
+
+  server.close();
+});

src/koa.ts

@@ -126,7 +126,11 @@ export const implementSchema = <State, Context, Schema extends OneSchema<any>>(
 
       // 3. Return the result and call the next middleware.
       ctx.response.body = response;
-      ctx.response.status = 200;
+      // If the response status is already set to a 200-level code, don't override it.
+      // This is the mechanism for allowing consumers to customize response codes.
+      if (ctx.response.status < 200 || ctx.response.status >= 300) {
+        ctx.response.status = 200;
+      }
       return next();
     };