/** * Comprehensive tests for API error handling * * Tests cover: * - Type guards (isAxiosError, isAPIErrorArray) * - Error parsing for all scenarios (network, HTTP status, structured errors) * - Field error extraction * - General error extraction * - Edge cases and error recovery */ import { AxiosError } from 'axios'; import { parseAPIError, getErrorMessage, getFieldErrors, getGeneralError, isAPIErrorArray, ERROR_MESSAGES, type APIError, } from '@/lib/api/errors'; describe('API Error Handling', () => { describe('isAPIErrorArray', () => { it('should return true for valid APIError array', () => { const errors: APIError[] = [ { code: 'AUTH_001', message: 'Invalid credentials' }, { code: 'VAL_002', message: 'Invalid email', field: 'email' }, ]; expect(isAPIErrorArray(errors)).toBe(true); }); it('should return false for non-array', () => { expect(isAPIErrorArray('not an array')).toBe(false); expect(isAPIErrorArray(null)).toBe(false); expect(isAPIErrorArray(undefined)).toBe(false); expect(isAPIErrorArray({})).toBe(false); }); it('should return false for empty array', () => { expect(isAPIErrorArray([])).toBe(true); // Empty array is technically valid }); it('should return false for array with invalid elements', () => { const invalidErrors = [ { code: 'AUTH_001' }, // missing message { message: 'Invalid credentials' }, // missing code 'string', // not an object ]; expect(isAPIErrorArray(invalidErrors)).toBe(false); }); it('should handle optional field property', () => { const errorsWithField: APIError[] = [ { code: 'VAL_001', message: 'Invalid input', field: 'email' }, ]; const errorsWithoutField: APIError[] = [{ code: 'AUTH_001', message: 'Invalid credentials' }]; expect(isAPIErrorArray(errorsWithField)).toBe(true); expect(isAPIErrorArray(errorsWithoutField)).toBe(true); }); it('should reject invalid field types', () => { const invalidFieldType = [ { code: 'VAL_001', message: 'Invalid', field: 123 }, // field must be string ]; expect(isAPIErrorArray(invalidFieldType)).toBe(false); }); }); describe('parseAPIError', () => { describe('Non-AxiosError handling', () => { it('should handle generic Error objects', () => { const error = new Error('Something went wrong'); const result = parseAPIError(error); expect(result).toEqual([ { code: 'UNKNOWN', message: 'Something went wrong', }, ]); }); it('should handle non-Error objects', () => { const error = { some: 'object' }; const result = parseAPIError(error); expect(result).toEqual([ { code: 'UNKNOWN', message: ERROR_MESSAGES['UNKNOWN'], }, ]); }); it('should handle null and undefined', () => { expect(parseAPIError(null)).toEqual([ { code: 'UNKNOWN', message: ERROR_MESSAGES['UNKNOWN'] }, ]); expect(parseAPIError(undefined)).toEqual([ { code: 'UNKNOWN', message: ERROR_MESSAGES['UNKNOWN'] }, ]); }); it('should handle strings', () => { const result = parseAPIError('some error string'); expect(result).toEqual([{ code: 'UNKNOWN', message: ERROR_MESSAGES['UNKNOWN'] }]); }); }); describe('Backend structured errors', () => { it('should parse structured error response', () => { const axiosError: Partial = { isAxiosError: true, message: 'Request failed', response: { status: 400, data: { success: false, errors: [ { code: 'AUTH_001', message: 'Invalid credentials' }, { code: 'VAL_002', message: 'Invalid email', field: 'email' }, ], }, statusText: 'Bad Request', headers: {}, config: {} as any, }, }; const result = parseAPIError(axiosError); expect(result).toEqual([ { code: 'AUTH_001', message: 'Invalid credentials' }, { code: 'VAL_002', message: 'Invalid email', field: 'email' }, ]); }); it('should handle single error in array', () => { const axiosError: Partial = { isAxiosError: true, message: 'Request failed', response: { status: 400, data: { errors: [{ code: 'USER_001', message: 'User not found' }], }, statusText: 'Bad Request', headers: {}, config: {} as any, }, }; const result = parseAPIError(axiosError); expect(result).toEqual([{ code: 'USER_001', message: 'User not found' }]); }); it('should handle multiple field errors', () => { const axiosError: Partial = { isAxiosError: true, message: 'Validation failed', response: { status: 422, data: { errors: [ { code: 'VAL_002', message: 'Invalid email', field: 'email' }, { code: 'VAL_003', message: 'Weak password', field: 'password' }, { code: 'VAL_004', message: 'Required', field: 'first_name' }, ], }, statusText: 'Unprocessable Entity', headers: {}, config: {} as any, }, }; const result = parseAPIError(axiosError); expect(result).toHaveLength(3); expect(result[0].field).toBe('email'); expect(result[1].field).toBe('password'); expect(result[2].field).toBe('first_name'); }); }); describe('Network errors', () => { it('should handle network error (no response)', () => { const axiosError: Partial = { isAxiosError: true, message: 'Network Error', response: undefined, }; const result = parseAPIError(axiosError); expect(result).toEqual([ { code: 'NETWORK_ERROR', message: ERROR_MESSAGES['NETWORK_ERROR'], }, ]); }); it('should handle timeout error', () => { const axiosError: Partial = { isAxiosError: true, message: 'timeout of 5000ms exceeded', response: undefined, code: 'ECONNABORTED', }; const result = parseAPIError(axiosError); expect(result).toEqual([ { code: 'NETWORK_ERROR', message: ERROR_MESSAGES['NETWORK_ERROR'], }, ]); }); }); describe('HTTP status-based errors', () => { it('should handle 401 Unauthorized', () => { const axiosError: Partial = { isAxiosError: true, message: 'Request failed', response: { status: 401, data: {}, statusText: 'Unauthorized', headers: {}, config: {} as any, }, }; const result = parseAPIError(axiosError); expect(result).toEqual([ { code: 'AUTH_003', message: ERROR_MESSAGES['AUTH_003'], }, ]); }); it('should handle 403 Forbidden', () => { const axiosError: Partial = { isAxiosError: true, message: 'Request failed', response: { status: 403, data: {}, statusText: 'Forbidden', headers: {}, config: {} as any, }, }; const result = parseAPIError(axiosError); expect(result).toEqual([ { code: 'FORBIDDEN', message: ERROR_MESSAGES['FORBIDDEN'], }, ]); }); it('should handle 404 Not Found', () => { const axiosError: Partial = { isAxiosError: true, message: 'Request failed', response: { status: 404, data: {}, statusText: 'Not Found', headers: {}, config: {} as any, }, }; const result = parseAPIError(axiosError); expect(result).toEqual([ { code: 'NOT_FOUND', message: ERROR_MESSAGES['NOT_FOUND'], }, ]); }); it('should handle 429 Too Many Requests', () => { const axiosError: Partial = { isAxiosError: true, message: 'Request failed', response: { status: 429, data: {}, statusText: 'Too Many Requests', headers: {}, config: {} as any, }, }; const result = parseAPIError(axiosError); expect(result).toEqual([ { code: 'RATE_LIMIT', message: ERROR_MESSAGES['RATE_LIMIT'], }, ]); }); it('should handle 500 Internal Server Error', () => { const axiosError: Partial = { isAxiosError: true, message: 'Request failed', response: { status: 500, data: {}, statusText: 'Internal Server Error', headers: {}, config: {} as any, }, }; const result = parseAPIError(axiosError); expect(result).toEqual([ { code: 'SERVER_ERROR', message: ERROR_MESSAGES['SERVER_ERROR'], }, ]); }); it('should handle 502 Bad Gateway', () => { const axiosError: Partial = { isAxiosError: true, message: 'Request failed', response: { status: 502, data: {}, statusText: 'Bad Gateway', headers: {}, config: {} as any, }, }; const result = parseAPIError(axiosError); expect(result).toEqual([ { code: 'SERVER_ERROR', message: ERROR_MESSAGES['SERVER_ERROR'], }, ]); }); it('should handle 503 Service Unavailable', () => { const axiosError: Partial = { isAxiosError: true, message: 'Request failed', response: { status: 503, data: {}, statusText: 'Service Unavailable', headers: {}, config: {} as any, }, }; const result = parseAPIError(axiosError); expect(result).toEqual([ { code: 'SERVER_ERROR', message: ERROR_MESSAGES['SERVER_ERROR'], }, ]); }); }); describe('Fallback error handling', () => { it('should handle unrecognized status code with message', () => { const axiosError: Partial = { isAxiosError: true, message: 'Custom error message', response: { status: 418, // I'm a teapot data: {}, statusText: "I'm a teapot", headers: {}, config: {} as any, }, }; const result = parseAPIError(axiosError); expect(result).toEqual([ { code: 'UNKNOWN', message: 'Custom error message', }, ]); }); it('should handle response with non-structured data', () => { const axiosError: Partial = { isAxiosError: true, message: 'Request failed', response: { status: 400, data: 'Plain text error', statusText: 'Bad Request', headers: {}, config: {} as any, }, }; const result = parseAPIError(axiosError); expect(result).toEqual([ { code: 'UNKNOWN', message: 'Request failed', }, ]); }); }); describe('Priority testing', () => { it('should prioritize structured errors over status codes', () => { const axiosError: Partial = { isAxiosError: true, message: 'Request failed', response: { status: 401, data: { errors: [{ code: 'CUSTOM_ERROR', message: 'Custom structured error' }], }, statusText: 'Unauthorized', headers: {}, config: {} as any, }, }; const result = parseAPIError(axiosError); // Should return structured error, not the 401 default expect(result).toEqual([{ code: 'CUSTOM_ERROR', message: 'Custom structured error' }]); }); }); }); describe('getErrorMessage', () => { it('should return message for known error code', () => { expect(getErrorMessage('AUTH_001')).toBe('Invalid email or password'); expect(getErrorMessage('USER_002')).toBe('This email is already registered'); expect(getErrorMessage('VAL_002')).toBe('Email format is invalid'); }); it('should return UNKNOWN message for unknown code', () => { expect(getErrorMessage('UNKNOWN_CODE')).toBe(ERROR_MESSAGES['UNKNOWN']); expect(getErrorMessage('')).toBe(ERROR_MESSAGES['UNKNOWN']); }); it('should handle all documented error codes', () => { const codes = [ 'AUTH_001', 'AUTH_002', 'AUTH_003', 'AUTH_004', 'USER_001', 'USER_002', 'USER_003', 'USER_004', 'VAL_001', 'VAL_002', 'VAL_003', 'VAL_004', 'ORG_001', 'ORG_002', 'ORG_003', 'PERM_001', 'PERM_002', 'PERM_003', 'RATE_001', 'SESSION_001', 'SESSION_002', 'SESSION_003', 'NETWORK_ERROR', 'SERVER_ERROR', 'UNKNOWN', 'FORBIDDEN', 'NOT_FOUND', 'RATE_LIMIT', ]; codes.forEach((code) => { const message = getErrorMessage(code); expect(message).toBeTruthy(); expect(typeof message).toBe('string'); expect(message.length).toBeGreaterThan(0); }); }); }); describe('getFieldErrors', () => { it('should extract field-specific errors', () => { const errors: APIError[] = [ { code: 'VAL_002', message: 'Invalid email format', field: 'email' }, { code: 'VAL_003', message: 'Password too weak', field: 'password' }, { code: 'AUTH_001', message: 'Invalid credentials' }, // no field ]; const result = getFieldErrors(errors); expect(result).toEqual({ email: 'Invalid email format', password: 'Password too weak', }); }); it('should return empty object when no field errors', () => { const errors: APIError[] = [ { code: 'AUTH_001', message: 'Invalid credentials' }, { code: 'SERVER_ERROR', message: 'Server error' }, ]; const result = getFieldErrors(errors); expect(result).toEqual({}); }); it('should return empty object for empty array', () => { const result = getFieldErrors([]); expect(result).toEqual({}); }); it('should use error code message if message is missing', () => { const errors: APIError[] = [{ code: 'VAL_002', message: '', field: 'email' }]; const result = getFieldErrors(errors); expect(result.email).toBe(ERROR_MESSAGES['VAL_002']); }); it('should handle multiple errors for same field (last one wins)', () => { const errors: APIError[] = [ { code: 'VAL_001', message: 'First error', field: 'email' }, { code: 'VAL_002', message: 'Second error', field: 'email' }, ]; const result = getFieldErrors(errors); expect(result.email).toBe('Second error'); }); }); describe('getGeneralError', () => { it('should return first non-field error', () => { const errors: APIError[] = [ { code: 'VAL_002', message: 'Invalid email', field: 'email' }, { code: 'AUTH_001', message: 'Invalid credentials' }, { code: 'SERVER_ERROR', message: 'Server error' }, ]; const result = getGeneralError(errors); expect(result).toBe('Invalid credentials'); }); it('should return undefined when only field errors exist', () => { const errors: APIError[] = [ { code: 'VAL_002', message: 'Invalid email', field: 'email' }, { code: 'VAL_003', message: 'Weak password', field: 'password' }, ]; const result = getGeneralError(errors); expect(result).toBeUndefined(); }); it('should return undefined for empty array', () => { const result = getGeneralError([]); expect(result).toBeUndefined(); }); it('should use error code message if message is missing', () => { const errors: APIError[] = [{ code: 'AUTH_001', message: '' }]; const result = getGeneralError(errors); expect(result).toBe(ERROR_MESSAGES['AUTH_001']); }); it('should skip field errors and find general error', () => { const errors: APIError[] = [ { code: 'VAL_001', message: 'Field error 1', field: 'field1' }, { code: 'VAL_002', message: 'Field error 2', field: 'field2' }, { code: 'VAL_003', message: 'Field error 3', field: 'field3' }, { code: 'SERVER_ERROR', message: 'General server error' }, ]; const result = getGeneralError(errors); expect(result).toBe('General server error'); }); }); describe('Error message completeness', () => { it('should have non-empty messages for all error codes', () => { Object.entries(ERROR_MESSAGES).forEach(([_code, message]) => { expect(message).toBeTruthy(); expect(message.length).toBeGreaterThan(0); expect(message).not.toBe(''); }); }); it('should have user-friendly messages', () => { // Check that messages don't contain technical jargon or error codes Object.entries(ERROR_MESSAGES).forEach(([_code, message]) => { expect(message).not.toContain('null'); expect(message).not.toContain('undefined'); expect(message).not.toContain('Error:'); // Messages should start with capital letter expect(message[0]).toMatch(/[A-Z]/); }); }); }); });