Task 12: Create MaterialsToDeleteDAO with SQL injection protection

Implement MaterialsToDeleteDAO class with secure parameterized queries following
the pattern established in Task 11 (commit 5aafb23).

Features:
- getMaterialsToDeleteByManagers(): Query materials_to_delete table with
  optional filtering by manager_names using parameterized queries
- getAllMaterialsToDelete(): Wrapper to retrieve all materials without filtering

Security:
- Uses parameterized queries (@param0, @param1, etc.) to prevent SQL injection
- Parameters passed separately from query string via executeSQLServerQuery()
- Input validation for empty arrays
- Comprehensive test coverage including SQL injection attempt scenarios

Testing:
- 11 comprehensive unit tests covering all methods and edge cases
- Tests verify parameterized query pattern prevents SQL injection
- All tests passing (12/12 including existing tests)

Files:
- src/main/dao/materials-to-delete.dao.ts: DAO implementation
- tests/unit/dao/materials-to-delete.dao.test.ts: Unit tests

Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>

src/main/dao/materials-to-delete.dao.ts

@@ -0,0 +1,61 @@
+import { DatabaseService } from '../services/database.service';
+import { LoggerService } from '../services/logger.service';
+
+export class MaterialsToDeleteDAO {
+  constructor(private dbService: DatabaseService) {}
+
+  /**
+   * Query materials_to_delete table and return distinct material codes
+   * @param managerNames - Optional array of manager names to filter by. Pass null to get all materials.
+   * @returns Promise<string[]> - Array of distinct material codes
+   */
+  async getMaterialsToDeleteByManagers(
+    managerNames: string[] | null
+  ): Promise<string[]> {
+    try {
+      // Input validation
+      if (managerNames && managerNames.length === 0) {
+        LoggerService.warn('Empty manager names array provided, returning empty result');
+        return [];
+      }
+
+      LoggerService.info(
+        `Querying materials_to_delete${managerNames ? ` for ${managerNames.length} managers` : ' (all managers)'}`
+      );
+
+      // Build base query
+      let query = `
+        SELECT DISTINCT material_code
+        FROM materials_to_delete
+      `;
+
+      let params: string[] | undefined;
+
+      // Add WHERE clause with parameterized query if manager names provided
+      // SECURITY: Use parameterized queries to prevent SQL injection
+      if (managerNames && managerNames.length > 0) {
+        const placeholders = managerNames.map((_, i) => `@param${i}`).join(',');
+        query += ` WHERE manager_name IN (${placeholders})`;
+        params = managerNames;
+      }
+
+      // Execute query with parameters (if any)
+      const result = await this.dbService.executeSQLServerQuery(query, params);
+      const materials = result.rows.map((row: any) => row.material_code);
+
+      LoggerService.info(`Found ${materials.length} materials to delete`);
+      return materials;
+    } catch (error) {
+      LoggerService.error('Failed to query materials_to_delete table', error);
+      throw error;
+    }
+  }
+
+  /**
+   * Get all materials from materials_to_delete table without filtering
+   * @returns Promise<string[]> - Array of all distinct material codes
+   */
+  async getAllMaterialsToDelete(): Promise<string[]> {
+    return this.getMaterialsToDeleteByManagers(null);
+  }
+}

tests/unit/dao/materials-to-delete.dao.test.ts

@@ -0,0 +1,232 @@
+import { MaterialsToDeleteDAO } from '../../../src/main/dao/materials-to-delete.dao';
+import { DatabaseService } from '../../../src/main/services/database.service';
+
+// Mock LoggerService to avoid Electron app dependency
+jest.mock('../../../src/main/services/logger.service', () => ({
+  LoggerService: {
+    info: jest.fn(),
+    warn: jest.fn(),
+    error: jest.fn(),
+    debug: jest.fn(),
+  },
+}));
+
+describe('MaterialsToDeleteDAO', () => {
+  let dao: MaterialsToDeleteDAO;
+  let mockDbService: jest.Mocked<DatabaseService>;
+
+  beforeEach(() => {
+    // Clear all mocks before each test
+    jest.clearAllMocks();
+
+    // Create a mock DatabaseService
+    mockDbService = {
+      executeSQLServerQuery: jest.fn(),
+    } as any;
+
+    dao = new MaterialsToDeleteDAO(mockDbService);
+  });
+
+  describe('getMaterialsToDeleteByManagers', () => {
+    it('should return all materials when managerNames is null', async () => {
+      const mockResult = {
+        rows: [
+          { material_code: 'MAT001' },
+          { material_code: 'MAT002' },
+          { material_code: 'MAT003' },
+        ],
+        rowCount: 3,
+      };
+
+      mockDbService.executeSQLServerQuery.mockResolvedValue(mockResult);
+
+      const result = await dao.getMaterialsToDeleteByManagers(null);
+
+      expect(result).toEqual(['MAT001', 'MAT002', 'MAT003']);
+      expect(mockDbService.executeSQLServerQuery).toHaveBeenCalledTimes(1);
+
+      // Verify the query does not contain WHERE clause
+      const queryCall = mockDbService.executeSQLServerQuery.mock.calls[0];
+      const query = queryCall[0];
+      expect(query).not.toContain('WHERE');
+      expect(query).toContain('SELECT DISTINCT material_code');
+      expect(query).toContain('FROM materials_to_delete');
+    });
+
+    it('should return materials filtered by manager names using parameterized query', async () => {
+      const managerNames = ['Manager1', 'Manager2'];
+      const mockResult = {
+        rows: [
+          { material_code: 'MAT001' },
+          { material_code: 'MAT002' },
+        ],
+        rowCount: 2,
+      };
+
+      mockDbService.executeSQLServerQuery.mockResolvedValue(mockResult);
+
+      const result = await dao.getMaterialsToDeleteByManagers(managerNames);
+
+      expect(result).toEqual(['MAT001', 'MAT002']);
+      expect(mockDbService.executeSQLServerQuery).toHaveBeenCalledTimes(1);
+
+      // Verify parameterized query is used (SQL injection protection)
+      const queryCall = mockDbService.executeSQLServerQuery.mock.calls[0];
+      const query = queryCall[0];
+      const params = queryCall[1];
+
+      expect(query).toContain('WHERE manager_name IN');
+      expect(query).toContain('@param0');
+      expect(query).toContain('@param1');
+
+      // Verify parameters are passed separately (not concatenated in query)
+      expect(params).toEqual(managerNames);
+
+      // Ensure no string concatenation of values in query
+      expect(query).not.toContain("'Manager1'");
+      expect(query).not.toContain("'Manager2'");
+    });
+
+    it('should return empty array when managerNames is empty', async () => {
+      const result = await dao.getMaterialsToDeleteByManagers([]);
+
+      expect(result).toEqual([]);
+      expect(mockDbService.executeSQLServerQuery).not.toHaveBeenCalled();
+    });
+
+    it('should handle single manager name', async () => {
+      const managerNames = ['Manager1'];
+      const mockResult = {
+        rows: [{ material_code: 'MAT001' }],
+        rowCount: 1,
+      };
+
+      mockDbService.executeSQLServerQuery.mockResolvedValue(mockResult);
+
+      const result = await dao.getMaterialsToDeleteByManagers(managerNames);
+
+      expect(result).toEqual(['MAT001']);
+      expect(mockDbService.executeSQLServerQuery).toHaveBeenCalledTimes(1);
+
+      const queryCall = mockDbService.executeSQLServerQuery.mock.calls[0];
+      expect(queryCall[0]).toContain('@param0');
+      expect(queryCall[1]).toEqual(['Manager1']);
+    });
+
+    it('should return empty array when no materials found', async () => {
+      const mockResult = {
+        rows: [],
+        rowCount: 0,
+      };
+
+      mockDbService.executeSQLServerQuery.mockResolvedValue(mockResult);
+
+      const result = await dao.getMaterialsToDeleteByManagers(['Manager1']);
+
+      expect(result).toEqual([]);
+    });
+
+    it('should handle SQL injection attempts via parameterized query', async () => {
+      const maliciousInput = [
+        "Manager1'; DROP TABLE materials_to_delete; --",
+        "Manager2' OR '1'='1",
+      ];
+
+      const mockResult = {
+        rows: [],
+        rowCount: 0,
+      };
+
+      mockDbService.executeSQLServerQuery.mockResolvedValue(mockResult);
+
+      await dao.getMaterialsToDeleteByManagers(maliciousInput);
+
+      // Verify parameters are passed as values, not concatenated
+      const queryCall = mockDbService.executeSQLServerQuery.mock.calls[0];
+      const query = queryCall[0];
+      const params = queryCall[1];
+
+      // The malicious strings should be in params, not in query
+      expect(params).toEqual(maliciousInput);
+
+      // Query should only contain placeholders, not actual values
+      expect(query).not.toContain('DROP TABLE');
+      expect(query).not.toContain('OR 1=1');
+      expect(query).toMatch(/@param\d+/);
+    });
+
+    it('should throw error when database query fails', async () => {
+      const dbError = new Error('Database connection failed');
+      mockDbService.executeSQLServerQuery.mockRejectedValue(dbError);
+
+      await expect(
+        dao.getMaterialsToDeleteByManagers(['Manager1'])
+      ).rejects.toThrow('Database connection failed');
+    });
+
+    it('should handle large number of manager names', async () => {
+      const managerNames = Array.from({ length: 100 }, (_, i) => `Manager${i}`);
+      const mockResult = {
+        rows: [{ material_code: 'MAT001' }],
+        rowCount: 1,
+      };
+
+      mockDbService.executeSQLServerQuery.mockResolvedValue(mockResult);
+
+      const result = await dao.getMaterialsToDeleteByManagers(managerNames);
+
+      expect(result).toEqual(['MAT001']);
+
+      // Verify all parameters are passed
+      const queryCall = mockDbService.executeSQLServerQuery.mock.calls[0];
+      expect(queryCall[1]).toEqual(managerNames);
+      expect(queryCall[1]?.length).toBe(100);
+    });
+  });
+
+  describe('getAllMaterialsToDelete', () => {
+    it('should return all materials by calling getMaterialsToDeleteByManagers with null', async () => {
+      const mockResult = {
+        rows: [
+          { material_code: 'MAT001' },
+          { material_code: 'MAT002' },
+          { material_code: 'MAT003' },
+        ],
+        rowCount: 3,
+      };
+
+      mockDbService.executeSQLServerQuery.mockResolvedValue(mockResult);
+
+      const result = await dao.getAllMaterialsToDelete();
+
+      expect(result).toEqual(['MAT001', 'MAT002', 'MAT003']);
+      expect(mockDbService.executeSQLServerQuery).toHaveBeenCalledTimes(1);
+
+      // Verify query without filter
+      const queryCall = mockDbService.executeSQLServerQuery.mock.calls[0];
+      expect(queryCall[0]).not.toContain('WHERE');
+    });
+
+    it('should propagate errors from getMaterialsToDeleteByManagers', async () => {
+      const dbError = new Error('Database error');
+      mockDbService.executeSQLServerQuery.mockRejectedValue(dbError);
+
+      await expect(dao.getAllMaterialsToDelete()).rejects.toThrow(
+        'Database error'
+      );
+    });
+
+    it('should return empty array when no materials exist', async () => {
+      const mockResult = {
+        rows: [],
+        rowCount: 0,
+      };
+
+      mockDbService.executeSQLServerQuery.mockResolvedValue(mockResult);
+
+      const result = await dao.getAllMaterialsToDelete();
+
+      expect(result).toEqual([]);
+    });
+  });
+});