import * as fsp from 'fs/promises';
import * as os from 'os';
import * as path from 'path';
describe('logger', () => {
const originalEnv = {
LOG_FILE: process.env.LOG_FILE,
LOG_LEVEL: process.env.LOG_LEVEL,
};
afterEach(() => {
if (originalEnv.LOG_FILE === undefined) {
delete process.env.LOG_FILE;
} else {
process.env.LOG_FILE = originalEnv.LOG_FILE;
}
if (originalEnv.LOG_LEVEL === undefined) {
delete process.env.LOG_LEVEL;
} else {
process.env.LOG_LEVEL = originalEnv.LOG_LEVEL;
}
jest.restoreAllMocks();
jest.resetModules();
});
it('writes log messages to the configured file', async () => {
const tempDir = await fsp.mkdtemp(path.join(os.tmpdir(), 'kb-logger-file-'));
const logFile = path.join(tempDir, 'logs', 'app.log');
process.env.LOG_FILE = logFile;
process.env.LOG_LEVEL = 'debug';
await jest.isolateModulesAsync(async () => {
const { logger } = await import('./logger.js');
logger.info('File target message');
logger.debug('debug content');
await new Promise((resolve) => setImmediate(resolve));
});
await expect(fsp.stat(path.dirname(logFile))).resolves.toBeTruthy();
const fileContents = await fsp.readFile(logFile, 'utf-8');
expect(fileContents).toContain('File target message');
expect(fileContents).toContain('[DEBUG] debug content');
});
it('falls back to stderr when log file cannot be initialized', async () => {
const stderrSpy = jest.spyOn(process.stderr, 'write').mockImplementation(() => true);
const tempDir = await fsp.mkdtemp(path.join(os.tmpdir(), 'kb-logger-stderr-'));
const lockedDir = path.join(tempDir, 'locked');
await fsp.mkdir(lockedDir, { recursive: true });
await fsp.chmod(lockedDir, 0o500);
const logFile = path.join(lockedDir, 'app.log');
process.env.LOG_FILE = logFile;
try {
await jest.isolateModulesAsync(async () => {
const { logger } = await import('./logger.js');
logger.info('Fallback message');
await new Promise((resolve) => setImmediate(resolve));
});
} finally {
await fsp.chmod(lockedDir, 0o700);
}
const stderrOutput = stderrSpy.mock.calls.flat().join('');
expect(stderrOutput).toMatch(/Failed to (initialize|write log)|Log file stream error/);
});
});
