Example #1
0
func ExampleLogger() {
	var buf bytes.Buffer
	logger := log.New(&buf, "logger: ", log.Lshortfile)
	logger.Print("Hello, log file!")

	fmt.Print(&buf)
	// Output:
	// logger: example_test.go:17: Hello, log file!
}
Example #2
0
func TestWriteToWithLog(t *testing.T) {
	defer remove(t, "log.txt")
	os.Remove("log.txt")
	l := log.New(nil, "", 0)
	defer WriteToWithLog("log.txt", l).Close()

	want := "some log\n"
	l.Println("some log")
	fmt.Fprintln(os.Stdout, "This is from stdout")
	fmt.Fprintln(os.Stderr, "This is from stderr")
	got := readFile(t, "log.txt")

	if got != want {
		t.Errorf("\nwant: '%s'\n got: '%s'", want, got)
	}
}
Example #3
0
func TestRotateWithLog(t *testing.T) {
	os.Remove("log.txt")
	os.Remove("log.txt.old")
	l := log.New(nil, "", 0)
	stdout := os.Stdout
	stderr := os.Stderr
	defer remove(t, "log.txt", "log.txt.old")

	rl := WriteToWithLog("log.txt", l)
	defer rl.Close()
	l.Println("some log")
	err := os.Rename("log.txt", "log.txt.old")
	if err != nil {
		os.Stdout = stdout
		os.Stderr = stderr
		t.Fatalf("TestRotate(): %v\n", err)
	}
	l.Println("new filename")

	got := readFile(t, "log.txt.old")
	want := "some log\nnew filename\n"

	if got != want {
		t.Errorf("log file renamed failed\nwant: '%s'\n got: '%v'", want, got)
	}

	rl.rotate()
	want = "This is after rotation\n"
	l.Printf(want)

	os.Stdout = stdout
	os.Stderr = stderr
	got = readFile(t, "log.txt")

	if got != want {
		t.Errorf("rotate() failed\nwant: '%s'\n got: '%v'", want, got)
	}
}