feat: Add unit tests for backend validators and configure Jest.

Backend/tests/unit/validators/usermanagement.validator.test.ts

@@ -0,0 +1,59 @@
+import {
+    getUserByIdValidator,
+    updateUserRoleValidator,
+} from '@/validators/usermanagement.validator';
+
+describe('getUserByIdValidator', () => {
+    it('should pass with valid id', () => {
+        const { error } = getUserByIdValidator.validate({ id: 1 });
+        expect(error).toBeUndefined();
+    });
+
+    it('should fail without id', () => {
+        const { error } = getUserByIdValidator.validate({});
+        expect(error).toBeDefined();
+    });
+
+    it('should fail with non-numeric id', () => {
+        const { error } = getUserByIdValidator.validate({ id: 'abc' });
+        expect(error).toBeDefined();
+        expect(error?.details[0].message).toMatch(/ID must be a number/i);
+    });
+
+    it('should pass with id = 0', () => {
+        // Joi number() allows 0 by default unless positive() is specified
+        const { error } = getUserByIdValidator.validate({ id: 0 });
+        expect(error).toBeUndefined();
+    });
+});
+
+describe('updateUserRoleValidator', () => {
+    it('should pass with valid id and role_id', () => {
+        const { error } = updateUserRoleValidator.validate({ id: 1, role_id: 2 });
+        expect(error).toBeUndefined();
+    });
+
+    it('should fail without id', () => {
+        const { error } = updateUserRoleValidator.validate({ role_id: 2 });
+        expect(error).toBeDefined();
+    });
+
+    it('should fail without role_id', () => {
+        const { error } = updateUserRoleValidator.validate({ id: 1 });
+        expect(error).toBeDefined();
+        // Joi uses field name in message when custom messages don't match
+        expect(error?.details[0].message).toContain('role_id');
+    });
+
+    it('should fail with non-numeric role_id', () => {
+        const { error } = updateUserRoleValidator.validate({ id: 1, role_id: 'admin' });
+        expect(error).toBeDefined();
+        expect(error?.details[0].message).toMatch(/Role ID must be a number/i);
+    });
+
+    it('should fail with non-numeric id', () => {
+        const { error } = updateUserRoleValidator.validate({ id: 'abc', role_id: 1 });
+        expect(error).toBeDefined();
+        expect(error?.details[0].message).toMatch(/ID must be a number/i);
+    });
+});