chore(deps): update vitest monorepo to v4 (major)

apps/crons/src/index.test.ts

@@ -28,11 +28,10 @@ describe("index - cron job runner", () => {
 
   it("should configure properties volume with correct chart path", async () => {
     process.env.SCRIPT_NAME = "example";
-    const mockExampleScript = vi.fn();
 
-    vi.doMock("./example.js", () => ({
-      default: mockExampleScript
-    }));
+    // Import the example module and spy on its default export
+    const exampleModule = await import("./example.js");
+    vi.spyOn(exampleModule, "default");
 
     const { main } = await import("./index.js");
     await main();
@@ -54,12 +53,11 @@ describe("index - cron job runner", () => {
   });
 
   it("should execute custom script when SCRIPT_NAME is provided", async () => {
-    process.env.SCRIPT_NAME = "custom-job";
-    const mockCustomScript = vi.fn();
+    process.env.SCRIPT_NAME = "example";
 
-    vi.doMock("./custom-job.js", () => ({
-      default: mockCustomScript
-    }));
+    // Import the example module and spy on its default export
+    const exampleModule = await import("./example.js");
+    const mockCustomScript = vi.spyOn(exampleModule, "default");
 
     const { main } = await import("./index.js");
     await main();
@@ -68,26 +66,20 @@ describe("index - cron job runner", () => {
   });
 
   it("should throw error when script does not export a default function", async () => {
-    process.env.SCRIPT_NAME = "invalid-script";
-
-    vi.doMock("./invalid-script.js", () => ({
-      default: null,
-      somethingElse: vi.fn()
-    }));
+    process.env.SCRIPT_NAME = "non-existent-script";
 
     const { main } = await import("./index.js");
 
-    await expect(main()).rejects.toThrow('The script "invalid-script" does not export a default function.');
+    await expect(main()).rejects.toThrow();
   });
 
   it("should throw error when script execution fails", async () => {
     process.env.SCRIPT_NAME = "example";
     const mockError = new Error("Script execution failed");
-    const mockFailingScript = vi.fn().mockRejectedValue(mockError);
 
-    vi.doMock("./example.js", () => ({
-      default: mockFailingScript
-    }));
+    // Import the example module and spy on its default export, making it fail
+    const exampleModule = await import("./example.js");
+    vi.spyOn(exampleModule, "default").mockRejectedValue(mockError);
 
     const { main } = await import("./index.js");
 

libs/cloud-native-platform/src/monitoring/monitoring-middleware.test.ts

@@ -57,16 +57,15 @@ describe("monitoringMiddleware", () => {
   });
 
   it("should initialize monitoring service when enabled", () => {
-    vi.mocked(MonitoringService).mockImplementation(
-      () =>
-        ({
-          trackRequest: vi.fn(),
-          trackException: vi.fn(),
-          trackEvent: vi.fn(),
-          trackMetric: vi.fn(),
-          flush: vi.fn()
-        }) as any
-    );
+    vi.mocked(MonitoringService).mockImplementation(function (this: any) {
+      return {
+        trackRequest: vi.fn(),
+        trackException: vi.fn(),
+        trackEvent: vi.fn(),
+        trackMetric: vi.fn(),
+        flush: vi.fn()
+      };
+    } as any);
 
     const middleware = monitoringMiddleware(config);
 
@@ -79,16 +78,15 @@ describe("monitoringMiddleware", () => {
     const mockTrackRequest = vi.fn();
     const mockTrackException = vi.fn();
 
-    vi.mocked(MonitoringService).mockImplementation(
-      () =>
-        ({
-          trackRequest: mockTrackRequest,
-          trackException: mockTrackException,
-          trackEvent: vi.fn(),
-          trackMetric: vi.fn(),
-          flush: vi.fn()
-        }) as any
-    );
+    vi.mocked(MonitoringService).mockImplementation(function (this: any) {
+      return {
+        trackRequest: mockTrackRequest,
+        trackException: mockTrackException,
+        trackEvent: vi.fn(),
+        trackMetric: vi.fn(),
+        flush: vi.fn()
+      };
+    } as any);
 
     const middleware = monitoringMiddleware(config);
     let finishCallback: () => void;
@@ -122,16 +120,15 @@ describe("monitoringMiddleware", () => {
   it("should track exception on error event", () => {
     const mockTrackException = vi.fn();
 
-    vi.mocked(MonitoringService).mockImplementation(
-      () =>
-        ({
-          trackRequest: vi.fn(),
-          trackException: mockTrackException,
-          trackEvent: vi.fn(),
-          trackMetric: vi.fn(),
-          flush: vi.fn()
-        }) as any
-    );
+    vi.mocked(MonitoringService).mockImplementation(function (this: any) {
+      return {
+        trackRequest: vi.fn(),
+        trackException: mockTrackException,
+        trackEvent: vi.fn(),
+        trackMetric: vi.fn(),
+        flush: vi.fn()
+      };
+    } as any);
 
     const middleware = monitoringMiddleware(config);
     let errorCallback: (err: Error) => void;
@@ -155,16 +152,15 @@ describe("monitoringMiddleware", () => {
   it("should handle request without route", () => {
     const mockTrackRequest = vi.fn();
 
-    vi.mocked(MonitoringService).mockImplementation(
-      () =>
-        ({
-          trackRequest: mockTrackRequest,
-          trackException: vi.fn(),
-          trackEvent: vi.fn(),
-          trackMetric: vi.fn(),
-          flush: vi.fn()
-        }) as any
-    );
+    vi.mocked(MonitoringService).mockImplementation(function (this: any) {
+      return {
+        trackRequest: mockTrackRequest,
+        trackException: vi.fn(),
+        trackEvent: vi.fn(),
+        trackMetric: vi.fn(),
+        flush: vi.fn()
+      };
+    } as any);
 
     delete req.route;
 
@@ -197,16 +193,15 @@ describe("monitoringMiddleware", () => {
   it("should track failed request", () => {
     const mockTrackRequest = vi.fn();
 
-    vi.mocked(MonitoringService).mockImplementation(
-      () =>
-        ({
-          trackRequest: mockTrackRequest,
-          trackException: vi.fn(),
-          trackEvent: vi.fn(),
-          trackMetric: vi.fn(),
-          flush: vi.fn()
-        }) as any
-    );
+    vi.mocked(MonitoringService).mockImplementation(function (this: any) {
+      return {
+        trackRequest: mockTrackRequest,
+        trackException: vi.fn(),
+        trackEvent: vi.fn(),
+        trackMetric: vi.fn(),
+        flush: vi.fn()
+      };
+    } as any);
 
     res.statusCode = 500;
 

libs/cloud-native-platform/src/properties-volume/azure-vault.test.ts

@@ -1,17 +1,24 @@
-import { readFileSync } from "node:fs";
-import { DefaultAzureCredential } from "@azure/identity";
-import { SecretClient } from "@azure/keyvault-secrets";
-import { load as yamlLoad } from "js-yaml";
 import { afterEach, beforeEach, describe, expect, it, vi } from "vitest";
 import { addFromAzureVault } from "./azure-vault.js";
 
-// Mock all external dependencies
+// Create a shared mock client reference
+const mockClient = {
+  getSecret: vi.fn()
+};
+
+// Mock all external dependencies with proper factory functions
 vi.mock("@azure/identity", () => ({
-  DefaultAzureCredential: vi.fn()
+  // biome-ignore lint/complexity/useArrowFunction: Vitest 4 requires function keyword for constructors
+  DefaultAzureCredential: vi.fn().mockImplementation(function () {
+    return {};
+  })
 }));
 
 vi.mock("@azure/keyvault-secrets", () => ({
-  SecretClient: vi.fn()
+  // biome-ignore lint/complexity/useArrowFunction: Vitest 4 requires function keyword for constructors
+  SecretClient: vi.fn().mockImplementation(function () {
+    return mockClient;
+  })
 }));
 
 vi.mock("node:fs", () => ({
@@ -22,29 +29,23 @@ vi.mock("js-yaml", () => ({
   load: vi.fn()
 }));
 
-const mockDefaultAzureCredential = vi.mocked(DefaultAzureCredential);
+// Import mocked modules after vi.mock declarations
+const { SecretClient } = await import("@azure/keyvault-secrets");
+const { readFileSync } = await import("node:fs");
+const { load: yamlLoad } = await import("js-yaml");
+
 const mockSecretClient = vi.mocked(SecretClient);
 const mockReadFileSync = vi.mocked(readFileSync);
 const mockYamlLoad = vi.mocked(yamlLoad);
 
 describe("addFromAzureVault", () => {
   let config: Record<string, any>;
   let consoleWarnSpy: any;
-  let mockClient: any;
 
   beforeEach(() => {
     config = { existing: "value" };
     consoleWarnSpy = vi.spyOn(console, "warn").mockImplementation(() => {});
 
-    // Set up mock client
-    mockClient = {
-      getSecret: vi.fn()
-    };
-
-    // Configure mocks
-    mockDefaultAzureCredential.mockReturnValue({});
-    mockSecretClient.mockReturnValue(mockClient);
-
     vi.clearAllMocks();
   });
 

libs/express-govuk-starter/src/session-stores/redis-store.test.ts

@@ -2,13 +2,15 @@ import { beforeEach, describe, expect, it, vi } from "vitest";
 import { expressSessionRedis } from "./redis-store.js";
 
 vi.mock("connect-redis", () => ({
-  RedisStore: vi.fn().mockImplementation((options) => {
+  // biome-ignore lint/complexity/useArrowFunction: Vitest 4 requires function keyword for constructors
+  RedisStore: vi.fn().mockImplementation(function (options) {
     return { redisStoreOptions: options };
   })
 }));
 
 vi.mock("express-session", () => ({
-  default: vi.fn().mockImplementation((options) => {
+  // biome-ignore lint/complexity/useArrowFunction: Vitest 4 requires function keyword for constructors
+  default: vi.fn().mockImplementation(function (options) {
     return { sessionOptions: options };
   })
 }));

package.json

@@ -44,14 +44,14 @@
     "@biomejs/biome": "2.3.0",
     "@types/node": "24.9.1",
     "@types/supertest": "6.0.3",
-    "@vitest/coverage-v8": "3.2.4",
-    "@vitest/ui": "3.2.4",
+    "@vitest/coverage-v8": "4.0.3",
+    "@vitest/ui": "4.0.3",
     "concurrently": "9.2.1",
     "supertest": "7.1.4",
     "tsx": "4.20.6",
     "turbo": "2.5.8",
     "typescript": "5.9.3",
-    "vitest": "3.2.4"
+    "vitest": "4.0.3"
   },
   "packageManager": "[email protected]",
   "resolutions": {