feat: use --app-name in error page title

- Replace hardcoded 'code-server' with {{APP_NAME}} template in error.html
- Add APP_NAME replacement in errors.ts using req.args['app-name']
- Add tests for custom app-name and default value

Author: RyanAI

src/browser/pages/error.html

@@ -11,7 +11,7 @@
       content="style-src 'self'; manifest-src 'self'; img-src 'self' data:; font-src 'self' data:;"
     />
     <meta name="color-scheme" content="light dark" />
-    <title>{{ERROR_TITLE}} - code-server</title>
+    <title>{{ERROR_TITLE}} - {{APP_NAME}}</title>
     <link rel="icon" href="{{CS_STATIC_BASE}}/src/browser/media/favicon-dark-support.svg" />
     <link rel="alternate icon" href="{{CS_STATIC_BASE}}/src/browser/media/favicon.ico" />
     <link rel="manifest" href="/manifest.json" crossorigin="use-credentials" />

src/node/routes/errors.ts

@@ -57,7 +57,8 @@ export const errorHandler: express.ErrorRequestHandler = async (err, req, res, n
       replaceTemplates(req, content)
         .replace(/{{ERROR_TITLE}}/g, statusCode.toString())
         .replace(/{{ERROR_HEADER}}/g, statusCode.toString())
-        .replace(/{{ERROR_BODY}}/g, escapeHtml(err.message)),
+        .replace(/{{ERROR_BODY}}/g, escapeHtml(err.message))
+        .replace(/{{APP_NAME}}/g, (req.args && req.args["app-name"]) || "code-server"),
     )
   } else {
     res.json({

test/unit/node/routes/errors.test.ts

@@ -20,9 +20,45 @@ describe("error page is rendered for text/html requests", () => {
     expect(res.status).toHaveBeenCalledWith(404)
     expect(res.send).toHaveBeenCalledWith(expect.not.stringContaining("<script>"))
   })
+
+  it("should use custom app-name in error page title", async () => {
+    const err = {
+      statusCode: 404,
+      message: "Not found",
+    }
+    const req = createRequest({ "app-name": "MyCodeServer" })
+    const res = {
+      status: jest.fn().mockReturnValue(this),
+      send: jest.fn().mockReturnValue(this),
+      set: jest.fn().mockReturnValue(this),
+    } as unknown as express.Response
+
+    await errorHandler(err, req, res, jest.fn())
+    expect(res.send).toHaveBeenCalledWith(
+      expect.stringContaining("<title>404 - MyCodeServer</title>"),
+    )
+  })
+
+  it("should use default 'code-server' when app-name is not set", async () => {
+    const err = {
+      statusCode: 500,
+      message: "Internal error",
+    }
+    const req = createRequest()
+    const res = {
+      status: jest.fn().mockReturnValue(this),
+      send: jest.fn().mockReturnValue(this),
+      set: jest.fn().mockReturnValue(this),
+    } as unknown as express.Response
+
+    await errorHandler(err, req, res, jest.fn())
+    expect(res.send).toHaveBeenCalledWith(
+      expect.stringContaining("<title>500 - code-server</title>"),
+    )
+  })
 })
 
-function createRequest(): express.Request {
+function createRequest(args?: Record<string, string>): express.Request {
   return {
     headers: {
       accept: ["text/html"],
@@ -31,5 +67,6 @@ function createRequest(): express.Request {
     query: {
       to: "test",
     },
+    args: args,
   } as unknown as express.Request
 }