From e289b515b13b376aaa66f12d8d630d607cd1e060 Mon Sep 17 00:00:00 2001
From: Le Vivilet <levivlet@pm.me>
Date: Fri, 27 Dec 2024 12:47:10 +0100
Subject: [PATCH] feature: add server timing response header

---
 .../src/parts/GetResponse/GetResponse.ts      | 34 +++++++++++++------
 .../test/WebViewProtocol.test.ts              |  8 +++++
 2 files changed, 31 insertions(+), 11 deletions(-)

diff --git a/packages/preview-process/src/parts/GetResponse/GetResponse.ts b/packages/preview-process/src/parts/GetResponse/GetResponse.ts
index d3ed3dcb..4fed8df0 100644
--- a/packages/preview-process/src/parts/GetResponse/GetResponse.ts
+++ b/packages/preview-process/src/parts/GetResponse/GetResponse.ts
@@ -8,16 +8,28 @@ import { NotFoundResponse } from '../Responses/NotFoundResponse.ts'
 import * as Routes from '../Routes/Routes.ts'
 
 export const getResponse = async (request: RequestOptions, options: HandlerOptions): Promise<Response> => {
-  if (request.method !== HttpMethod.Get && request.method !== HttpMethod.Head) {
-    return new MethodNotAllowedResponse()
-  }
-  const matchedRoute = FindMatchingRoute.findMatchingRoute(request.path, Routes.routes)
-  if (!matchedRoute) {
-    return new NotFoundResponse()
-  }
-  const response = await matchedRoute.handler(request, options)
-  if (request.method === HttpMethod.Head) {
-    return new HeadResponse(response.status, response.headers)
+  const start = performance.now()
+
+  try {
+    if (request.method !== HttpMethod.Get && request.method !== HttpMethod.Head) {
+      return new MethodNotAllowedResponse()
+    }
+    const matchedRoute = FindMatchingRoute.findMatchingRoute(request.path, Routes.routes)
+    if (!matchedRoute) {
+      return new NotFoundResponse()
+    }
+    const response = await matchedRoute.handler(request, options)
+    if (request.method === HttpMethod.Head) {
+      return new HeadResponse(response.status, response.headers)
+    }
+
+    // Add Server-Timing header
+    const duration = Math.round(performance.now() - start)
+    response.headers.set('Server-Timing', `total;dur=${duration}`)
+
+    return response
+  } catch (error) {
+    const response = new NotFoundResponse()
+    return response
   }
-  return response
 }
diff --git a/packages/preview-process/test/WebViewProtocol.test.ts b/packages/preview-process/test/WebViewProtocol.test.ts
index b3c713c3..94c6a6fe 100644
--- a/packages/preview-process/test/WebViewProtocol.test.ts
+++ b/packages/preview-process/test/WebViewProtocol.test.ts
@@ -54,6 +54,7 @@ test('get - css file', async () => {
     headers: {
       'Content-Type': 'text/css',
       'Cross-Origin-Resource-Policy': 'same-origin',
+      'Server-Timing': expect.any(String),
     },
   })
   expect(response.body.toString()).toBe('a')
@@ -69,6 +70,7 @@ test('get - javascript file', async () => {
     headers: {
       'Content-Type': 'text/javascript',
       'Cross-Origin-Resource-Policy': 'same-origin',
+      'Server-Timing': expect.any(String),
     },
   })
   expect(response.body.toString()).toBe('console.log("test")')
@@ -102,6 +104,7 @@ test('get - preview injected', async () => {
     headers: {
       'Content-Type': 'text/javascript',
       'Cross-Origin-Resource-Policy': 'same-origin',
+      'Server-Timing': expect.any(String),
     },
   })
   expect(response.body).toBeDefined()
@@ -118,6 +121,7 @@ test('get - index.html', async () => {
       'Content-Type': 'text/html',
       'Cross-Origin-Resource-Policy': 'cross-origin',
       'Cross-Origin-Embedder-Policy': 'require-corp',
+      'Server-Timing': expect.any(String),
     },
   })
   expect(response.body.toString()).toBe('<h1>hello world</h1>')
@@ -162,6 +166,7 @@ test('get - png image file', async () => {
       headers: {
         'Content-Type': 'image/png',
         'Cross-Origin-Resource-Policy': 'same-origin',
+        'Server-Timing': expect.any(String),
       },
     },
   })
@@ -179,6 +184,7 @@ test('get - svg file', async () => {
       headers: {
         'Content-Type': 'image/svg+xml',
         'Cross-Origin-Resource-Policy': 'same-origin',
+        'Server-Timing': expect.any(String),
       },
     },
   })
@@ -196,6 +202,7 @@ test('get - json file', async () => {
       headers: {
         'Content-Type': 'application/json',
         'Cross-Origin-Resource-Policy': 'same-origin',
+        'Server-Timing': expect.any(String),
       },
     },
   })
@@ -213,6 +220,7 @@ test('get - unknown file type', async () => {
       headers: {
         'Content-Type': 'text/plain',
         'Cross-Origin-Resource-Policy': 'same-origin',
+        'Server-Timing': expect.any(String),
       },
     },
   })