add io.Writer and StdLogger adaptors #7

adaptor.go

@@ -0,0 +1,30 @@
+package lgr
+
+import (
+	"log"
+	"strings"
+)
+
+// Writer holds lgr.L and wraps with io.Writer interface
+type Writer struct {
+	L
+	level string // if defined added to each message
+}
+
+// Write to lgr.L, trim EOL
+func (w *Writer) Write(p []byte) (n int, err error) {
+	w.Logf(strings.TrimSuffix(w.level+string(p), "\n"))
+	return len(p), nil
+}
+
+// ToWriter makes io.Writer for given lgr.L with optional level
+func ToWriter(l L, level string) *Writer {
+	if level != "" && !strings.HasSuffix(level, " ") {
+		level += " "
+	}
+	return &Writer{l, level}
+}
+
+func ToStdLogger(l L, level string) *log.Logger {
+	return log.New(ToWriter(l, level), "", 0)
+}

adaptor_test.go

@@ -0,0 +1,55 @@
+package lgr
+
+import (
+	"bytes"
+	"testing"
+	"time"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+)
+
+func TestAdaptor_ToWriter(t *testing.T) {
+	rout, rerr := bytes.NewBuffer([]byte{}), bytes.NewBuffer([]byte{})
+	l := New(Out(rout), Err(rerr), Msec, LevelBraces)
+	l.now = func() time.Time { return time.Date(2018, 1, 7, 13, 2, 34, 0, time.Local) }
+
+	wr := ToWriter(l, "WARN")
+	sz, err := wr.Write([]byte("something blah 123"))
+	require.NoError(t, err)
+	assert.Equal(t, 18, sz)
+	assert.Equal(t, "2018/01/07 13:02:34.000 [WARN]  something blah 123\n", rout.String())
+}
+
+func TestAdaptor_ToWriterNoLevel(t *testing.T) {
+	rout, rerr := bytes.NewBuffer([]byte{}), bytes.NewBuffer([]byte{})
+	l := New(Out(rout), Err(rerr), Msec, LevelBraces)
+	l.now = func() time.Time { return time.Date(2018, 1, 7, 13, 2, 34, 0, time.Local) }
+
+	wr := ToWriter(l, "")
+	sz, err := wr.Write([]byte("something blah 123"))
+	require.NoError(t, err)
+	assert.Equal(t, 18, sz)
+	assert.Equal(t, "2018/01/07 13:02:34.000 [INFO]  something blah 123\n", rout.String())
+
+	rout.Reset()
+	rerr.Reset()
+	_, err = wr.Write([]byte("INFO something blah 123"))
+	require.NoError(t, err)
+	assert.Equal(t, "2018/01/07 13:02:34.000 [INFO]  something blah 123\n", rout.String())
+}
+
+func TestAdaptor_ToStdLogger(t *testing.T) {
+	rout, rerr := bytes.NewBuffer([]byte{}), bytes.NewBuffer([]byte{})
+	l := New(Out(rout), Err(rerr), Msec, LevelBraces)
+	l.now = func() time.Time { return time.Date(2018, 1, 7, 13, 2, 34, 0, time.Local) }
+
+	wr := ToStdLogger(l, "WARN")
+	wr.Print("something")
+	assert.Equal(t, "2018/01/07 13:02:34.000 [WARN]  something\n", rout.String())
+
+	rout.Reset()
+	rerr.Reset()
+	wr.Printf("xxx %s", "yyy")
+	assert.Equal(t, "2018/01/07 13:02:34.000 [WARN]  xxx yyy\n", rout.String())
+}