/**
* @file logger.test.ts
* @description Unit tests for shared/logger module
*
* Tests the logging functionality including:
* - Log level filtering
* - Message formatting
* - Stream separation (stdout vs stderr)
* - Environment variable configuration
*
* @since 3.1.1
*/
import { describe, it, expect, vi, beforeEach, afterEach } from 'vitest';
import { logger, LogLevel } from '../../../src/shared/logger.js';
describe('shared/logger', () => {
let consoleErrorSpy: ReturnType<typeof vi.spyOn>;
let consoleWarnSpy: ReturnType<typeof vi.spyOn>;
let consoleLogSpy: ReturnType<typeof vi.spyOn>;
let originalEnv: string | undefined;
beforeEach(() => {
// Spy on console methods
consoleErrorSpy = vi.spyOn(console, 'error').mockImplementation(() => {});
consoleWarnSpy = vi.spyOn(console, 'warn').mockImplementation(() => {});
consoleLogSpy = vi.spyOn(console, 'log').mockImplementation(() => {});
originalEnv = process.env.LOG_LEVEL;
});
afterEach(() => {
// Restore console methods
consoleErrorSpy.mockRestore();
consoleWarnSpy.mockRestore();
consoleLogSpy.mockRestore();
process.env.LOG_LEVEL = originalEnv;
vi.clearAllMocks();
});
describe('LogLevel enum', () => {
it('should define all log levels', () => {
expect(LogLevel.ERROR).toBe('error');
expect(LogLevel.WARN).toBe('warn');
expect(LogLevel.INFO).toBe('info');
expect(LogLevel.DEBUG).toBe('debug');
});
});
describe('logger.error', () => {
it('should log error messages to stderr', () => {
logger.error('Test error');
expect(consoleErrorSpy).toHaveBeenCalledTimes(1);
const call = consoleErrorSpy.mock.calls[0][0];
expect(call).toContain('ERROR');
expect(call).toContain('Test error');
});
it('should include metadata in error logs', () => {
logger.error('Test error', { code: 500, details: 'Internal error' });
expect(consoleErrorSpy).toHaveBeenCalledTimes(1);
const call = consoleErrorSpy.mock.calls[0][0];
expect(call).toContain('ERROR');
expect(call).toContain('Test error');
expect(call).toContain('"code":500');
expect(call).toContain('"details":"Internal error"');
});
it('should include ISO timestamp', () => {
logger.error('Test error');
const call = consoleErrorSpy.mock.calls[0][0];
// Check for ISO timestamp pattern [YYYY-MM-DDTHH:MM:SS.MMMZ]
expect(call).toMatch(/\[\d{4}-\d{2}-\d{2}T\d{2}:\d{2}:\d{2}\.\d{3}Z\]/);
});
});
describe('logger.warn', () => {
it('should log warning messages to stderr', () => {
logger.warn('Test warning');
expect(consoleWarnSpy).toHaveBeenCalledTimes(1);
const call = consoleWarnSpy.mock.calls[0][0];
expect(call).toContain('WARN');
expect(call).toContain('Test warning');
});
it('should include metadata in warning logs', () => {
logger.warn('Deprecation warning', { feature: 'old-api' });
const call = consoleWarnSpy.mock.calls[0][0];
expect(call).toContain('WARN');
expect(call).toContain('Deprecation warning');
expect(call).toContain('"feature":"old-api"');
});
});
describe('logger.info', () => {
it('should log info messages to stdout', () => {
logger.info('Test info');
expect(consoleLogSpy).toHaveBeenCalledTimes(1);
const call = consoleLogSpy.mock.calls[0][0];
expect(call).toContain('INFO');
expect(call).toContain('Test info');
});
it('should include metadata in info logs', () => {
logger.info('Server started', { port: 3000, version: '1.0.0' });
const call = consoleLogSpy.mock.calls[0][0];
expect(call).toContain('INFO');
expect(call).toContain('Server started');
expect(call).toContain('"port":3000');
expect(call).toContain('"version":"1.0.0"');
});
});
describe('logger.debug', () => {
it('should log debug messages to stdout', () => {
logger.debug('Test debug');
expect(consoleLogSpy).toHaveBeenCalledTimes(1);
const call = consoleLogSpy.mock.calls[0][0];
expect(call).toContain('DEBUG');
expect(call).toContain('Test debug');
});
it('should include metadata in debug logs', () => {
logger.debug('Processing request', { requestId: '123', operation: 'matrix_multiply' });
const call = consoleLogSpy.mock.calls[0][0];
expect(call).toContain('DEBUG');
expect(call).toContain('Processing request');
expect(call).toContain('"requestId":"123"');
expect(call).toContain('"operation":"matrix_multiply"');
});
});
describe('message formatting', () => {
it('should format messages with timestamp, level, and message', () => {
logger.info('Formatted message');
const call = consoleLogSpy.mock.calls[0][0];
// Format: [timestamp] LEVEL: message
expect(call).toMatch(/\[\d{4}-\d{2}-\d{2}T\d{2}:\d{2}:\d{2}\.\d{3}Z\] INFO: Formatted message/);
});
it('should handle empty metadata gracefully', () => {
logger.info('No metadata', {});
const call = consoleLogSpy.mock.calls[0][0];
expect(call).toContain('INFO');
expect(call).toContain('No metadata');
// Should have metadata object even if empty
expect(call).toContain('{}');
});
it('should handle complex nested metadata', () => {
logger.info('Complex data', {
user: { id: 1, name: 'Test' },
settings: { theme: 'dark', notifications: true }
});
const call = consoleLogSpy.mock.calls[0][0];
expect(call).toContain('INFO');
expect(call).toContain('Complex data');
expect(call).toContain('"user"');
expect(call).toContain('"id":1');
expect(call).toContain('"name":"Test"');
});
});
describe('stream separation', () => {
it('should use stderr for error and warn levels', () => {
logger.error('Error message');
logger.warn('Warning message');
expect(consoleErrorSpy).toHaveBeenCalledTimes(1);
expect(consoleWarnSpy).toHaveBeenCalledTimes(1);
expect(consoleLogSpy).not.toHaveBeenCalled();
});
it('should use stdout for info and debug levels', () => {
logger.info('Info message');
logger.debug('Debug message');
expect(consoleLogSpy).toHaveBeenCalledTimes(2);
expect(consoleErrorSpy).not.toHaveBeenCalled();
expect(consoleWarnSpy).not.toHaveBeenCalled();
});
});
});
