define public interface instead use *logrus.Logger

add example

fix lint issue with exhaustive

add new api

improve tests, format code

Update klogrus.go

Improve existing documentation

Update klogrus.go

Fix typos

Update klogrus.go

remove period

plugin/klogrus/go.mod

@@ -4,13 +4,16 @@ go 1.18
 
 require (
 	github.com/sirupsen/logrus v1.9.3
+	github.com/stretchr/testify v1.8.0
 	github.com/twmb/franz-go v1.14.3
 )
 
 require (
+	github.com/davecgh/go-spew v1.1.1 // indirect
 	github.com/klauspost/compress v1.16.7 // indirect
 	github.com/pierrec/lz4/v4 v4.1.18 // indirect
-	github.com/stretchr/testify v1.8.0 // indirect
+	github.com/pmezard/go-difflib v1.0.0 // indirect
 	github.com/twmb/franz-go/pkg/kmsg v1.6.1 // indirect
 	golang.org/x/sys v0.10.0 // indirect
+	gopkg.in/yaml.v3 v3.0.1 // indirect
 )

plugin/klogrus/go.sum

@@ -22,6 +22,7 @@ github.com/twmb/franz-go/pkg/kmsg v1.6.1/go.mod h1:se9Mjdt0Nwzc9lnjJ0HyDtLyBnaBD
 golang.org/x/sys v0.0.0-20220715151400-c0bba94af5f8/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
 golang.org/x/sys v0.10.0 h1:SqMFp9UcQJZa+pmYuAKjd9xq1f0j5rLcDIk0mj4qAsA=
 golang.org/x/sys v0.10.0/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
+gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405 h1:yhCVgyC4o1eVCa2tZl7eS0r+SDo693bJlVdllGtEeKM=
 gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
 gopkg.in/yaml.v3 v3.0.0-20200313102051-9f266ea9e77c/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=
 gopkg.in/yaml.v3 v3.0.1 h1:fxVm/GzAzEWqLHuvctI91KS9hhNmmWOoWu0XTYJS7CA=

plugin/klogrus/klogrus.go

@@ -7,17 +7,37 @@ import (
 	"github.com/twmb/franz-go/pkg/kgo"
 )
 
+var (
+	_ FieldLogger = (*logrus.Logger)(nil)
+	_ kgo.Logger  = (*Logger)(nil)
+)
+
+// FieldLogger interface combines logrus.FieldLogger with GetLevel method
+// useful to represent a wrapper around *logrus.Logger.
+type FieldLogger interface {
+	logrus.FieldLogger
+	GetLevel() logrus.Level
+}
+
 // Logger provides the kgo.Logger interface for usage in kgo.WithLogger when
 // initializing a client.
 type Logger struct {
-	lr *logrus.Logger
+	lr FieldLogger
 }
 
-// New returns a new Logger.
+// New returns a new Logger using a *logrus.Logger instance.
 func New(lr *logrus.Logger) *Logger {
 	return &Logger{lr}
 }
 
+// NewFieldLogger returns a new Logger using a FieldLogger interface.
+// it is isofunctional with New constructor, except it can accept either
+// *logrus.Logger or a possible wrapper that implements logrus.FieldLogger
+// and includes GetLevel method.
+func NewFieldLogger(fl FieldLogger) *Logger {
+	return &Logger{fl}
+}
+
 // Level is for the kgo.Logger interface.
 func (l *Logger) Level() kgo.LogLevel {
 	return logrusToKgoLevel(l.lr.GetLevel())
@@ -45,6 +65,8 @@ func kgoToLogrusLevel(level kgo.LogLevel) (logrus.Level, bool) {
 		return logrus.InfoLevel, true
 	case kgo.LogLevelDebug:
 		return logrus.DebugLevel, true
+	case kgo.LogLevelNone:
+		return logrus.TraceLevel, false
 	}
 	return logrus.TraceLevel, false
 }

plugin/klogrus/klogrus_test.go

@@ -0,0 +1,44 @@
+package klogrus_test
+
+import (
+	"testing"
+
+	"github.com/sirupsen/logrus"
+	"github.com/sirupsen/logrus/hooks/test"
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+
+	"github.com/twmb/franz-go/pkg/kgo"
+	"github.com/twmb/franz-go/plugin/klogrus"
+)
+
+func ExampleNew() {
+	l := klogrus.New(logrus.New())
+
+	l.Log(kgo.LogLevelInfo, "test message", "test-key", "test-val")
+	// Output:
+}
+
+func TestFieldLogger(t *testing.T) {
+	logger, hook := test.NewNullLogger()
+
+	l := klogrus.NewFieldLogger(logger)
+
+	level := l.Level()
+	assert.Equal(t, kgo.LogLevelInfo, level)
+
+	l.Log(kgo.LogLevelInfo, "test message", "test-key", "test-val")
+
+	require.Equal(t, 1, len(hook.Entries))
+	lastEntry := hook.LastEntry()
+
+	assert.Equal(t, logrus.InfoLevel, lastEntry.Level)
+	assert.Equal(t, "test message", lastEntry.Message)
+
+	value, ok := lastEntry.Data["test-key"]
+	assert.True(t, ok)
+	assert.Equal(t, "test-val", value)
+
+	hook.Reset()
+	assert.Nil(t, hook.LastEntry())
+}