func expectedLogFormat(tag, msg string) string { return fmt.Sprintf("\\[%s\\] [0-9]{4}/[0-9]{2}/[0-9]{2} [0-9]{2}:[0-9]{2}:[0-9]{2} %s\n", tag, msg) } var _ = Describe("NewFileLogger", func() { var ( fs *fakeboshsys.FakeFileSystem logFile boshsys.File ) BeforeEach(func() { fs = fakeboshsys.NewFakeFileSystem() var err error logFile, err = fs.TempFile("file-logger-test") Expect(err).ToNot(HaveOccurred()) err = logFile.Close() Expect(err).ToNot(HaveOccurred()) }) AfterEach(func() { logFile.Close() fs.RemoveAll(logFile.Name()) }) It("logs the formatted DEBUG message to the file", func() { logger, logFile, err := New(boshlog.LevelDebug, logFile.Name(), DefaultLogFileMode, fs) Expect(err).ToNot(HaveOccurred()) logger.Debug("TAG", "some %s info to log", "awesome") contents, err := fs.ReadFileString(logFile.Name())