func TestContext(t *testing.T) {
t.Parallel()
buf := &bytes.Buffer{}
logger := log.NewLogfmtLogger(buf)
kvs := []interface{}{"a", 123}
lc := log.NewContext(logger).With(kvs...)
kvs[1] = 0 // With should copy its key values
lc = lc.With("b", "c") // With should stack
if err := lc.Log("msg", "message"); err != nil {
t.Fatal(err)
}
if want, have := "a=123 b=c msg=message\n", buf.String(); want != have {
t.Errorf("\nwant: %shave: %s", want, have)
}
buf.Reset()
lc = lc.WithPrefix("p", "first")
if err := lc.Log("msg", "message"); err != nil {
t.Fatal(err)
}
if want, have := "p=first a=123 b=c msg=message\n", buf.String(); want != have {
t.Errorf("\nwant: %shave: %s", want, have)
}
}
func TestDefaultLevels(t *testing.T) {
buf := bytes.Buffer{}
logger := levels.New(log.NewLogfmtLogger(&buf))
logger.Debug("msg", "résumé") // of course you'd want to do this
if want, have := "level=debug msg=résumé\n", buf.String(); want != have {
t.Errorf("want %#v, have %#v", want, have)
}
buf.Reset()
logger.Info("msg", "Åhus")
if want, have := "level=info msg=Åhus\n", buf.String(); want != have {
t.Errorf("want %#v, have %#v", want, have)
}
buf.Reset()
logger.Error("msg", "© violation")
if want, have := "level=error msg=\"© violation\"\n", buf.String(); want != have {
t.Errorf("want %#v, have %#v", want, have)
}
buf.Reset()
logger.Crit("msg", " ")
if want, have := "level=crit msg=\"\\t\"\n", buf.String(); want != have {
t.Errorf("want %#v, have %#v", want, have)
}
}
func ExampleLevels() {
logger := levels.New(log.NewLogfmtLogger(os.Stdout))
logger.Debug("msg", "hello")
logger.With("context", "foo").Warn("err", "error")
// Output:
// level=debug msg=hello
// level=warn context=foo err=error
}
func ExampleContext() {
logger := log.NewLogfmtLogger(os.Stdout)
logger.Log("foo", 123)
ctx := log.NewContext(logger).With("level", "info")
ctx.Log()
ctx = ctx.With("msg", "hello")
ctx.Log()
ctx.With("a", 1).Log("b", 2)
// Output:
// foo=123
// level=info
// level=info msg=hello
// level=info msg=hello a=1 b=2
}
func TestSwapLogger(t *testing.T) {
var logger log.SwapLogger
// Zero value does not panic or error.
err := logger.Log("k", "v")
if got, want := err, error(nil); got != want {
t.Errorf("got %v, want %v", got, want)
}
buf := &bytes.Buffer{}
json := log.NewJSONLogger(buf)
logger.Swap(json)
if err := logger.Log("k", "v"); err != nil {
t.Error(err)
}
if got, want := buf.String(), `{"k":"v"}`+"\n"; got != want {
t.Errorf("got %v, want %v", got, want)
}
buf.Reset()
prefix := log.NewLogfmtLogger(buf)
logger.Swap(prefix)
if err := logger.Log("k", "v"); err != nil {
t.Error(err)
}
if got, want := buf.String(), "k=v\n"; got != want {
t.Errorf("got %v, want %v", got, want)
}
buf.Reset()
logger.Swap(nil)
if err := logger.Log("k", "v"); err != nil {
t.Error(err)
}
if got, want := buf.String(), ""; got != want {
t.Errorf("got %v, want %v", got, want)
}
}