feat: add x-request-id to the response (#96)

src/response.ts

@@ -378,6 +378,13 @@ export class Response extends Macroable {
       return
     }
 
+    /*
+     * ----------------------------------------
+     * SET X-REQUEST-ID HEADER
+     * ----------------------------------------
+     */
+    this.setRequestId()
+
     /*
      * ----------------------------------------
      * SET CONTENT-LENGTH HEADER
@@ -779,6 +786,18 @@ export class Response extends Macroable {
     return this
   }
 
+  /**
+   * Set X-Request-Id header by copying the header value from the request if it exists.
+   *
+   */
+  setRequestId(): this {
+    const requestId = this.request.headers['x-request-id']
+    if (requestId) {
+      this.header('X-Request-Id', requestId)
+    }
+    return this
+  }
+
   /**
    * Returns a boolean telling if the new response etag evaluates same
    * as the request header `if-none-match`. In case of `true`, the

tests/response.spec.ts

@@ -108,6 +108,18 @@ test.group('Response', (group) => {
     })
   })
 
+  test('set x-request-id header', async () => {
+    const { url } = await httpServer.create((req, res) => {
+      req.headers['x-request-id'] = '20241127'
+      const response = new ResponseFactory().merge({ req, res, encryption, router }).create()
+
+      response.send('<p> hello </p>')
+      response.finish()
+    })
+
+    await supertest(url).get('/').expect(200).expect('x-request-id', '20241127')
+  })
+
   test('get merged from http res object', async ({ assert }) => {
     const { url } = await httpServer.create((req, res) => {
       res.setHeader('content-type', 'application/json')