Rename defaultFormatter to formatter - it's the only one

The field is not the default formatter, it's the actual formatter set by
the user. The default formatter is used when this is empty and that is
to just JSON marshal the type.

logrusr.go

@@ -18,7 +18,8 @@ import (
 const logrusDiffToInfo = 4
 
 // FormatFunc is the function to format log values with for non primitive data.
-// By default, this is empty and the data will be JSON marshaled.
+// If this is not set (default) all unknown types will be JSON marshaled and
+// added as a string.
 type FormatFunc func(interface{}) interface{}
 
 // Option is options to give when construction a logrusr logger.
@@ -27,7 +28,7 @@ type Option func(l *logrusr)
 // WithFormatter will set the FormatFunc to use.
 func WithFormatter(f FormatFunc) Option {
 	return func(l *logrusr) {
-		l.defaultFormatter = f
+		l.formatter = f
 	}
 }
 
@@ -51,11 +52,11 @@ func WithName(name ...string) Option {
 }
 
 type logrusr struct {
-	name             []string
-	depth            int
-	reportCaller     bool
-	logger           *logrus.Entry
-	defaultFormatter FormatFunc
+	name         []string
+	depth        int
+	reportCaller bool
+	logger       *logrus.Entry
+	formatter    FormatFunc
 }
 
 // New will return a new logr.Logger created from a logrus.FieldLogger.
@@ -110,7 +111,7 @@ func (l *logrusr) Info(level int, msg string, keysAndValues ...interface{}) {
 	}
 
 	log.
-		WithFields(listToLogrusFields(l.defaultFormatter, keysAndValues...)).
+		WithFields(listToLogrusFields(l.formatter, keysAndValues...)).
 		Log(logrus.Level(level+logrusDiffToInfo), msg)
 }
 
@@ -124,7 +125,7 @@ func (l *logrusr) Error(err error, msg string, keysAndValues ...interface{}) {
 	}
 
 	log.
-		WithFields(listToLogrusFields(l.defaultFormatter, keysAndValues...)).
+		WithFields(listToLogrusFields(l.formatter, keysAndValues...)).
 		WithError(err).
 		Error(msg)
 }
@@ -136,7 +137,7 @@ func (l *logrusr) Error(err error, msg string, keysAndValues ...interface{}) {
 func (l *logrusr) WithValues(keysAndValues ...interface{}) logr.LogSink {
 	newLogger := l.copyLogger()
 	newLogger.logger = newLogger.logger.WithFields(
-		listToLogrusFields(l.defaultFormatter, keysAndValues...),
+		listToLogrusFields(l.formatter, keysAndValues...),
 	)
 
 	return newLogger
@@ -197,11 +198,11 @@ func listToLogrusFields(formatter FormatFunc, keysAndValues ...interface{}) logr
 // the formatter and actual logrus logger.
 func (l *logrusr) copyLogger() *logrusr {
 	newLogger := &logrusr{
-		name:             make([]string, len(l.name)),
-		depth:            l.depth,
-		reportCaller:     l.reportCaller,
-		logger:           l.logger.Dup(),
-		defaultFormatter: l.defaultFormatter,
+		name:         make([]string, len(l.name)),
+		depth:        l.depth,
+		reportCaller: l.reportCaller,
+		logger:       l.logger.Dup(),
+		formatter:    l.formatter,
 	}
 
 	copy(newLogger.name, l.name)