refactor: reorganize spec regeneration routes and add unit tests

- Removed the old spec regeneration routes and replaced them with a new structure under the app-spec directory for better modularity.
- Introduced unit tests for common functionalities in app-spec, covering state management and error handling.
- Added documentation on route organization patterns to improve maintainability and clarity for future development.

apps/server/tests/unit/routes/app-spec/common.test.ts

@@ -0,0 +1,103 @@
+import { describe, it, expect, beforeEach } from "vitest";
+import {
+  setRunningState,
+  getErrorMessage,
+  isRunning,
+  currentAbortController,
+} from "@/routes/app-spec/common.js";
+
+describe("app-spec/common.ts", () => {
+  beforeEach(() => {
+    // Reset state before each test
+    setRunningState(false, null);
+  });
+
+  describe("setRunningState", () => {
+    it("should set isRunning to true when running is true", () => {
+      setRunningState(true);
+      expect(isRunning).toBe(true);
+    });
+
+    it("should set isRunning to false when running is false", () => {
+      setRunningState(true);
+      setRunningState(false);
+      expect(isRunning).toBe(false);
+    });
+
+    it("should set currentAbortController when provided", () => {
+      const controller = new AbortController();
+      setRunningState(true, controller);
+      expect(currentAbortController).toBe(controller);
+    });
+
+    it("should set currentAbortController to null when not provided", () => {
+      const controller = new AbortController();
+      setRunningState(true, controller);
+      setRunningState(false);
+      expect(currentAbortController).toBe(null);
+    });
+
+    it("should set currentAbortController to null when explicitly passed null", () => {
+      const controller = new AbortController();
+      setRunningState(true, controller);
+      setRunningState(true, null);
+      expect(currentAbortController).toBe(null);
+    });
+
+    it("should update state multiple times correctly", () => {
+      const controller1 = new AbortController();
+      const controller2 = new AbortController();
+
+      setRunningState(true, controller1);
+      expect(isRunning).toBe(true);
+      expect(currentAbortController).toBe(controller1);
+
+      setRunningState(true, controller2);
+      expect(isRunning).toBe(true);
+      expect(currentAbortController).toBe(controller2);
+
+      setRunningState(false, null);
+      expect(isRunning).toBe(false);
+      expect(currentAbortController).toBe(null);
+    });
+  });
+
+  describe("getErrorMessage", () => {
+    it("should return message from Error instance", () => {
+      const error = new Error("Test error message");
+      expect(getErrorMessage(error)).toBe("Test error message");
+    });
+
+    it("should return 'Unknown error' for non-Error objects", () => {
+      expect(getErrorMessage("string error")).toBe("Unknown error");
+      expect(getErrorMessage(123)).toBe("Unknown error");
+      expect(getErrorMessage(null)).toBe("Unknown error");
+      expect(getErrorMessage(undefined)).toBe("Unknown error");
+      expect(getErrorMessage({})).toBe("Unknown error");
+      expect(getErrorMessage([])).toBe("Unknown error");
+    });
+
+    it("should return message from Error with empty message", () => {
+      const error = new Error("");
+      expect(getErrorMessage(error)).toBe("");
+    });
+
+    it("should handle Error objects with custom properties", () => {
+      const error = new Error("Base message");
+      (error as any).customProp = "custom value";
+      expect(getErrorMessage(error)).toBe("Base message");
+    });
+
+    it("should handle Error objects created with different constructors", () => {
+      class CustomError extends Error {
+        constructor(message: string) {
+          super(message);
+          this.name = "CustomError";
+        }
+      }
+
+      const customError = new CustomError("Custom error message");
+      expect(getErrorMessage(customError)).toBe("Custom error message");
+    });
+  });
+});