Add employees management module with database schema and validation

- Introduced `EmployeesModule` to manage employee data, including read and write controllers.
- Created database migrations for the `employees` table, including constraints and unique indexes.
- Implemented validation for employee fields such as name, code, and position with corresponding utility functions.
- Developed service and repository layers for handling employee data operations.
- Added unit tests for the employees service, repository, and controllers to ensure functionality and correctness.
- Updated application module to include the new `EmployeesModule` for better organization.

src/modules/configuration/employees/employee-fields.spec.ts

@@ -0,0 +1,108 @@
+import {
+  EMPLOYEE_CODE_MAX_LENGTH,
+  EMPLOYEE_NAME_MAX_LENGTH,
+  isAllowedCsvUpload,
+  isValidEmployeeCode,
+  isValidEmployeeName,
+  isValidEmployeePosition,
+  parseCsvRecord,
+} from './employee-fields';
+
+describe('employee fields', () => {
+  describe('isValidEmployeeName', () => {
+    it.each(['Ada', 'Jean Luc', 'A', 'North West Crew'])(
+      'accepts %s',
+      (name) => {
+        expect(isValidEmployeeName(name)).toBe(true);
+      },
+    );
+
+    it.each(['', 'Ada1', 'Jean-Luc', 'EMP_01', ' Ada', 'Ada ', 'Jean  Luc'])(
+      'rejects %s',
+      (name) => {
+        expect(isValidEmployeeName(name)).toBe(false);
+      },
+    );
+
+    it('rejects names longer than 64 characters', () => {
+      expect(
+        isValidEmployeeName('A'.repeat(EMPLOYEE_NAME_MAX_LENGTH + 1)),
+      ).toBe(false);
+      expect(isValidEmployeeName('A'.repeat(EMPLOYEE_NAME_MAX_LENGTH))).toBe(
+        true,
+      );
+    });
+  });
+
+  describe('isValidEmployeeCode', () => {
+    it.each(['EMP', 'EMP_01', 'A', 'ops2', 'A_b_1'])('accepts %s', (code) => {
+      expect(isValidEmployeeCode(code)).toBe(true);
+    });
+
+    it.each(['', 'EMP 01', 'EMP-01', 'EMP.01', ' EMP', 'EMP '])(
+      'rejects %s',
+      (code) => {
+        expect(isValidEmployeeCode(code)).toBe(false);
+      },
+    );
+
+    it('rejects codes longer than 16 characters', () => {
+      expect(
+        isValidEmployeeCode('A'.repeat(EMPLOYEE_CODE_MAX_LENGTH + 1)),
+      ).toBe(false);
+      expect(isValidEmployeeCode('A'.repeat(EMPLOYEE_CODE_MAX_LENGTH))).toBe(
+        true,
+      );
+    });
+  });
+
+  describe('isValidEmployeePosition', () => {
+    it.each(['sales', 'driver', 'crew'])('accepts %s', (position) => {
+      expect(isValidEmployeePosition(position)).toBe(true);
+    });
+
+    it.each(['', 'Sales', 'pilot', 'crew '])('rejects %s', (position) => {
+      expect(isValidEmployeePosition(position)).toBe(false);
+    });
+  });
+
+  describe('parseCsvRecord', () => {
+    it('keeps commas inside quoted fields', () => {
+      expect(parseCsvRecord('EMP_01,Ada Lovelace,"sales, lead"')).toEqual([
+        'EMP_01',
+        'Ada Lovelace',
+        'sales, lead',
+      ]);
+    });
+
+    it('unescapes doubled quotes', () => {
+      expect(parseCsvRecord('"Say ""hello""",x')).toEqual(['Say "hello"', 'x']);
+    });
+  });
+
+  describe('isAllowedCsvUpload', () => {
+    it('accepts csv mime or .csv names', () => {
+      expect(
+        isAllowedCsvUpload({
+          mimetype: 'text/csv',
+          originalname: 'x.txt',
+        }),
+      ).toBe(true);
+      expect(
+        isAllowedCsvUpload({
+          mimetype: 'application/octet-stream',
+          originalname: 'employees.csv',
+        }),
+      ).toBe(true);
+    });
+
+    it('rejects non-csv files', () => {
+      expect(
+        isAllowedCsvUpload({
+          mimetype: 'application/pdf',
+          originalname: 'x.pdf',
+        }),
+      ).toBe(false);
+    });
+  });
+});