Update router and tests to fix issues

api/src/category.router.test.ts

@@ -1,35 +1,104 @@
 import { describe, it } from 'node:test';
 import assert from 'node:assert/strict';
-import { buildCategoryTree, CategoryNode } from './tree.utility.ts';
+import { createCategoryRouter } from './category.router.ts';
+import { CategoryRepository } from './category.repository.ts';
+import { Request, Response } from 'express';
 
-describe('Tree Utility - buildCategoryTree()', () => {
+// 1. Generate a mock factory for the Express Response object
-    it('should transform a flat list of ltree rows into a nested JSON structure', () => {
+function createMockResponse() {
-        const flatNodes: CategoryNode[] = [
+  const res: Partial<Response> = {};
-            { id: 1, name: 'Root', path: 'Top' },
+  const data: { statusCode: number; jsonPayload: any } = { statusCode: 200, jsonPayload: null };
-            { id: 3, name: 'Astronomy', path: 'Top.Science.Astronomy' },
-            { id: 2, name: 'Science', path: 'Top.Science' },
-            { id: 4, name: 'Gardening', path: 'Top.Hobbies.Gardening' },
-            { id: 5, name: 'Hobbies', path: 'Top.Hobbies' }
-        ];
 
-        const tree = buildCategoryTree(flatNodes);
+  res.status = function (code: number) {
+    data.statusCode = code;
+    return this as Response;
+  };
 
-        // Verify root nodes count
+  res.json = function (payload: any) {
-        assert.equal(tree.length, 1);
+    data.jsonPayload = payload;
-        assert.equal(tree[0].name, 'Root');
+    return this as Response;
+  };
 
-        // Verify second level ("Science" and "Hobbies")
+  return { mockRes: res as Response, data };
-        const rootChildren = tree[0].children;
+}
-        assert.equal(rootChildren.length, 2);
 
-        const scienceNode = rootChildren.find(c => c.name === 'Science');
+// 2. Generate a mock factory for the repository layer
-        const hobbiesNode = rootChildren.find(c => c.name === 'Hobbies');
+function createMockRepository(behavior: 'success' | 'failure') {
+  return {
+    findAllDescendants: async (path: string) => {
+      if (behavior === 'failure') throw new Error('Database connection failed');
+      // Return a valid single-root array format mimicking real ltree database outputs
+      return [
+        { id: 1, name: 'Top', path: 'Top' },
+        { id: 2, name: 'Science', path: 'Top.Science' }
+      ];
+    }
+  } as unknown as CategoryRepository;
+}
 
-        assert.ok(scienceNode);
+// Helper utility to safely extract the Express handler bypassing strict undefined types
-        assert.ok(hobbiesNode);
+function getRouteHandler(router: any): Function {
+  const routeLayer = router.stack.find((layer: any) => layer.route);
+  if (!routeLayer || !routeLayer.route || !routeLayer.route.stack) {
+    throw new Error('Could not find route handler in mock router stack');
+  }
+  return routeLayer.route.stack[0].handle; // Target the primary callback handler array element
+}
 
-        // Verify third level deeply nested child ("Astronomy")
+describe('Category Router Endpoints', () => {
-        assert.equal(scienceNode.children.length, 1);
+  
-        assert.equal(scienceNode.children[0].name, 'Astronomy');
+  it('GET /tree{/:path} - should return 200 and structural JSON array data on valid requests', async () => {
-    });
+    const mockRepo = createMockRepository('success');
+    const router = createCategoryRouter(mockRepo);
+    
+    const mockReq = { params: { path: 'Top' } } as unknown as Request;
+    const { mockRes, data } = createMockResponse();
+
+    const routeHandler = getRouteHandler(router);
+    await routeHandler(mockReq, mockRes);
+
+    assert.equal(data.statusCode, 200);
+    assert.equal(data.jsonPayload.success, true);
+    
+    // Correct alignment: buildCategoryTree returns an ARRAY of root nodes
+    assert.equal(Array.isArray(data.jsonPayload.data), true);
+    assert.equal(data.jsonPayload.data[0].name, 'Top');
+  });
+
+  it('GET /tree{/:path} - should return 400 Bad Request if ltree path contains malformed formatting', async () => {
+    const mockRepo = createMockRepository('success');
+    const router = createCategoryRouter(mockRepo);
+    
+    const mockReq = { params: { path: 'Top.Bad Path!' } } as unknown as Request;
+    const { mockRes, data } = createMockResponse();
+
+    const routeHandler = getRouteHandler(router);
+    await routeHandler(mockReq, mockRes);
+
+    assert.equal(data.statusCode, 400);
+    assert.equal(data.jsonPayload.success, false);
+    assert.match(data.jsonPayload.error, /Invalid path format/);
+  });
+
+  it('GET /tree{/:path} - should handle runtime database crashes gracefully with a 500 error status', async () => {
+    const mockRepo = createMockRepository('failure'); 
+    const router = createCategoryRouter(mockRepo);
+    
+    const mockReq = { params: { path: 'Top' } } as unknown as Request;
+    const { mockRes, data } = createMockResponse();
+
+    // Prevent console.error from cluttering the test runner feedback during intentional failures
+    const originalConsoleError = console.error;
+    console.error = () => {};
+
+    const routeHandler = getRouteHandler(router);
+    await routeHandler(mockReq, mockRes);
+
+    // Restore original logger tracking
+    console.error = originalConsoleError;
+
+    assert.equal(data.statusCode, 500);
+    assert.equal(data.jsonPayload.success, false);
+    assert.equal(data.jsonPayload.error, 'Internal Server Error');
+  });
 });

api/src/category.router.ts

@@ -2,34 +2,35 @@ import { Router, Request, Response } from 'express';
 import { CategoryRepository } from './category.repository.ts';
 import { buildCategoryTree } from './tree.utility.ts';
 
+// Clean regex pattern matching valid Postgres ltree structures
+const LTREE_REGEX = /^[A-Za-z0-9_]+(\.[A-Za-z0-9_]+)*$/;
+
 export function createCategoryRouter(repository: CategoryRepository): Router {
-    const router = Router();
+  const router = Router();
 
-    /**
+  router.get('/tree{/:path}', async (req: Request, res: Response): Promise<void> => {
-     * GET /api/categories/tree/:path?
+    try {
-     * Fetches all descendants of a path and returns them formatted as a tree.
+      const rawPath = req.params.path;
-     * If no path parameter is provided, it defaults to the root level.
+      const parentPath = Array.isArray(rawPath) ? rawPath[0] : (rawPath || 'Top');
-     */
-    router.get('/tree/:path?', async (req: Request, params: Response): Promise<void> => {
-        try {
-            const rawPath = req.params.path;
 
-            const parentPath = Array.isArray(rawPath)
+      // 1. INPUT VALIDATION: Stop malicious or broken ltree strings early
-                ? rawPath[0]
+      if (!LTREE_REGEX.test(parentPath)) {
-                : (rawPath || 'Top');  // default fallback root value in the database
+        res.status(400).json({ 
+          success: false, 
+          error: 'Invalid path format. Path elements must be alphanumeric separated by dots.' 
+        });
+        return; // Break execution early
+      }
 
-            // Fetch flat database rows from our repository
+      const flatRows = await repository.findAllDescendants(parentPath);
-            const flatRows = await repository.findAllDescendants(parentPath);
+      const nestedTree = buildCategoryTree(flatRows);
+      
+      res.json({ success: true, data: nestedTree });
+    } catch (error) {
+      console.error('Failed to resolve category tree:', error);
+      res.status(500).json({ success: false, error: 'Internal Server Error' });
+    }
+  });
 
-            // Format data into nested layout
+  return router;
-            const nestedTree = buildCategoryTree(flatRows);
-
-            params.json({ success: true, data: nestedTree });
-        } catch (error) {
-            console.error('Failed to resolve category tree:', error);
-            params.status(500).json({ success: false, error: 'Internal Server Error' });
-        }
-    });
-
-    return router;
 }