chore: add mock for "no servers" example

Author: kantord

src/lib/api-client.ts

@@ -13,13 +13,16 @@
 
 "use server";
 
-import { headers as nextHeaders } from "next/headers";
+import { cookies, headers as nextHeaders } from "next/headers";
 import { redirect } from "next/navigation";
 import { createClient, createConfig } from "@/generated/client";
 import * as apiServices from "@/generated/sdk.gen";
 import { auth } from "./auth/auth";
 import { getValidOidcToken } from "./auth/token";
 
+const MOCK_SCENARIO_COOKIE = "mock-scenario";
+const MOCK_SCENARIO_HEADER = "X-Mock-Scenario";
+
 // Validate required environment variables at module load time (fail-fast)
 const API_BASE_URL = process.env.API_BASE_URL;
 
@@ -65,13 +68,22 @@ export async function getAuthenticatedClient(accessToken?: string) {
     accessToken = token;
   }
 
+  // Check for mock scenario cookie (development only)
+  const requestHeaders: Record<string, string> = {
+    Authorization: `Bearer ${accessToken}`,
+  };
+
+  const cookieStore = await cookies();
+  const mockScenario = cookieStore.get(MOCK_SCENARIO_COOKIE)?.value;
+  if (mockScenario) {
+    requestHeaders[MOCK_SCENARIO_HEADER] = mockScenario;
+  }
+
   // Create a new client instance per request to avoid race conditions
   const authenticatedClient = createClient(
     createConfig({
       baseUrl: API_BASE_URL,
-      headers: {
-        Authorization: `Bearer ${accessToken}`,
-      },
+      headers: requestHeaders,
     }),
   );
 

src/mocks/handlers.ts

@@ -1,8 +1,13 @@
 import type { RequestHandler } from "msw";
 import { autoGeneratedHandlers } from "./mocker";
+import { emptyServersHandlers } from "./scenarios/empty-servers";
 import { serverDetailHandlers } from "./server-detail";
 
 export const handlers: RequestHandler[] = [
+  // Scenario handlers (cookie-activated) - must come first
+  ...emptyServersHandlers,
+  // Custom handlers
   ...serverDetailHandlers,
+  // Auto-generated handlers (fallback)
   ...autoGeneratedHandlers,
 ];

src/mocks/mockScenario.ts

@@ -0,0 +1,47 @@
+import { type HttpHandler, http } from "msw";
+
+type HttpMethod =
+  | "get"
+  | "post"
+  | "put"
+  | "patch"
+  | "delete"
+  | "head"
+  | "options";
+
+const SCENARIO_HEADER = "x-mock-scenario";
+
+/**
+ * Creates scenario-specific mock handlers that only activate when the X-Mock-Scenario header matches.
+ * The header is set by the API client based on the "mock-scenario" cookie.
+ */
+export function mockScenario(
+  scenario: string,
+): Record<HttpMethod, typeof http.get> {
+  return new Proxy({} as Record<HttpMethod, typeof http.get>, {
+    get(_, method: HttpMethod) {
+      const httpMethod = http[method];
+      if (typeof httpMethod !== "function") return undefined;
+
+      return (
+        path: string,
+        handler: Parameters<typeof httpMethod>[1],
+      ): HttpHandler =>
+        httpMethod(path, (info) => {
+          const headerValue = info.request.headers.get(SCENARIO_HEADER);
+          console.log(
+            `[mockScenario] ${method.toUpperCase()} ${info.request.url}`,
+            `| header "${SCENARIO_HEADER}"="${headerValue}"`,
+            `| expected="${scenario}"`,
+            `| match=${headerValue === scenario}`,
+          );
+
+          if (headerValue !== scenario) {
+            return;
+          }
+          console.log(`[mockScenario] ACTIVATED scenario "${scenario}"`);
+          return handler(info);
+        });
+    },
+  });
+}

src/mocks/scenarios/empty-servers.ts

@@ -0,0 +1,15 @@
+import { HttpResponse } from "msw";
+import { mockScenario } from "../mockScenario";
+
+/**
+ * Empty servers scenario - returns an empty list of servers.
+ * Activate by setting cookie: mock-scenario=empty-servers
+ */
+export const emptyServersHandlers = [
+  mockScenario("empty-servers").get("*/registry/v0.1/servers", () => {
+    return HttpResponse.json({
+      servers: [],
+      metadata: { count: 0 },
+    });
+  }),
+];