Add and use Logger / FancyLogger interface

logging.go

@@ -18,15 +18,23 @@ package riak
 
 import (
 	"fmt"
-	"log"
 	"os"
 )
 
+// Logger represents a leveled logger, with methods representing
+// debug, warn, and error levels
+type Logger interface {
+	Debug(v ...interface{})
+	Debugf(format string, v ...interface{})
+	Warn(v ...interface{})
+	Warnf(format string, v ...interface{})
+	Error(v ...interface{})
+	Errorf(format string, v ...interface{})
+}
+
 // If true, debug messages will be written to the log
 var EnableDebugLogging = false
-
-var errLogger = log.New(os.Stderr, "", log.LstdFlags)
-var stdLogger = log.New(os.Stderr, "", log.LstdFlags)
+var logger Logger
 
 func init() {
 	if debugEnvVar := os.Getenv("RIAK_GO_CLIENT_DEBUG"); debugEnvVar != "" {
@@ -36,50 +44,45 @@ func init() {
 
 // SetLogger sets the standard logger used for
 // WARN and DEBUG (if enabled)
-func SetLogger(logger *log.Logger) {
-	stdLogger = logger
-}
-
-// SetErrorLogger sets the logger used for errors
-func SetErrorLogger(logger *log.Logger) {
-	errLogger = logger
+func SetLogger(l Logger) {
+	logger = l
 }
 
 // logDebug writes formatted string debug messages using Printf only if debug logging is enabled
 func logDebug(source, format string, v ...interface{}) {
 	if EnableDebugLogging {
-		stdLogger.Printf(fmt.Sprintf("[DEBUG] %s %s", source, format), v...)
+		logger.Debugf(fmt.Sprintf("%s %s", source, format), v...)
 	}
 }
 
 // logDebugln writes string debug messages using Println
 func logDebugln(source string, v ...interface{}) {
 	if EnableDebugLogging {
-		stdLogger.Println("[DEBUG]", source, v)
+		logger.Debug(source, v)
 	}
 }
 
 // logWarn writes formatted string warning messages using Printf
 func logWarn(source, format string, v ...interface{}) {
-	stdLogger.Printf(fmt.Sprintf("[WARNING] %s %s", source, format), v...)
+	logger.Warnf(fmt.Sprintf("%s %s", source, format), v...)
 }
 
 // logWarnln writes string warning messages using Println
 func logWarnln(source string, v ...interface{}) {
-	stdLogger.Println("[WARNING]", source, v)
+	logger.Warn(source, v)
 }
 
 // logError writes formatted string error messages using Printf
 func logError(source, format string, v ...interface{}) {
-	errLogger.Printf(fmt.Sprintf("[ERROR] %s %s", source, format), v...)
+	logger.Errorf(fmt.Sprintf("%s %s", source, format), v...)
 }
 
 // logErr writes err.Error() using Println
 func logErr(source string, err error) {
-	errLogger.Println("[ERROR]", source, err)
+	logger.Error(source, err)
 }
 
 // logErrorln writes an error message using Println
 func logErrorln(source string, v ...interface{}) {
-	errLogger.Println("[ERROR]", source, v)
+	logger.Error(source, v)
 }

logging_test.go

@@ -3,16 +3,75 @@ package riak
 import (
 	"bytes"
 	"fmt"
+	"io"
 	"log"
 	"strings"
 	"testing"
 )
 
+type fakeFancyLogger struct {
+	buf        io.Writer
+	lastCalled string
+}
+
+// appendNewline adds a newline, if one does not already exist at the
+// end of the format string.  This mimics log.Print[f|ln]'s behavior.
+func appendNewline(s string, w io.Writer) {
+	// taken from stdlib's log.Printf
+	if len(s) == 0 || s[len(s)-1] != '\n' {
+		w.Write([]byte(string('\n')))
+	}
+}
+
+func (logger *fakeFancyLogger) Println(v ...interface{}) {
+	fmt.Fprintln(logger.buf, v...)
+	logger.lastCalled = "Println"
+}
+
+func (logger *fakeFancyLogger) Printf(format string, v ...interface{}) {
+	fmt.Fprintf(logger.buf, format, v...)
+	appendNewline(format, logger.buf)
+	logger.lastCalled = "Printf"
+}
+
+func (logger *fakeFancyLogger) Debug(v ...interface{}) {
+	fmt.Fprintln(logger.buf, v...)
+	logger.lastCalled = "Debug"
+}
+
+func (logger *fakeFancyLogger) Debugf(format string, v ...interface{}) {
+	fmt.Fprintf(logger.buf, format, v...)
+	appendNewline(format, logger.buf)
+	logger.lastCalled = "Debugf"
+}
+
+func (logger *fakeFancyLogger) Warn(v ...interface{}) {
+	fmt.Fprintln(logger.buf, v...)
+	logger.lastCalled = "Warn"
+}
+
+func (logger *fakeFancyLogger) Warnf(format string, v ...interface{}) {
+	fmt.Fprintf(logger.buf, format, v...)
+	appendNewline(format, logger.buf)
+	logger.lastCalled = "Warnf"
+}
+
+func (logger *fakeFancyLogger) Error(v ...interface{}) {
+	fmt.Fprintln(logger.buf, v...)
+	logger.lastCalled = "Error"
+}
+
+func (logger *fakeFancyLogger) Errorf(format string, v ...interface{}) {
+	fmt.Fprintf(logger.buf, format, v...)
+	appendNewline(format, logger.buf)
+	logger.lastCalled = "Errorf"
+}
+
 func TestLog(t *testing.T) {
 	EnableDebugLogging = true
 
 	tests := []struct {
-		setLoggerFunc func(*log.Logger)
+		setLoggerFunc func(Logger)
 		logFunc       func(string, string, ...interface{})
 		prefix        string
 	}{
@@ -48,11 +107,54 @@ func TestLog(t *testing.T) {
 	}
 }
 
+func TestFancyLog(t *testing.T) {
+	EnableDebugLogging = true
+
+	tests := []struct {
+		setLoggerFunc func(Logger)
+		logFunc       func(string, string, ...interface{})
+		shouldCall    string
+	}{
+		{
+			SetErrorLogger,
+			logError,
+			"Errorf",
+		},
+		{
+			SetLogger,
+			logWarn,
+			"Warnf",
+		},
+		{
+			SetLogger,
+			logDebug,
+			"Debugf",
+		},
+	}
+
+	for _, tt := range tests {
+		buf := &bytes.Buffer{}
+		fancyLogger := &fakeFancyLogger{buf: buf}
+		tt.setLoggerFunc(fancyLogger)
+		tt.logFunc("[test]", "Hello %s!", "World")
+
+		actual := buf.String()
+		suffix := "[test] Hello World!\n"
+
+		if !strings.HasSuffix(actual, suffix) {
+			t.Errorf("Expected %s to end with %s", actual, suffix)
+		}
+		if fancyLogger.lastCalled != tt.shouldCall {
+			t.Errorf("Expected call to %s, got %s", tt.shouldCall, fancyLogger.lastCalled)
+		}
+	}
+}
+
 func TestLogln(t *testing.T) {
 	EnableDebugLogging = true
 
 	tests := []struct {
-		setLoggerFunc func(*log.Logger)
+		setLoggerFunc func(Logger)
 		logFunc       func(string, ...interface{})
 		prefix        string
 	}{
@@ -88,6 +190,49 @@ func TestLogln(t *testing.T) {
 	}
 }
 
+func TestFancyLogln(t *testing.T) {
+	EnableDebugLogging = true
+
+	tests := []struct {
+		setLoggerFunc func(Logger)
+		logFunc       func(string, ...interface{})
+		shouldCall    string
+	}{
+		{
+			SetErrorLogger,
+			logErrorln,
+			"Error",
+		},
+		{
+			SetLogger,
+			logWarnln,
+			"Warn",
+		},
+		{
+			SetLogger,
+			logDebugln,
+			"Debug",
+		},
+	}
+
+	for _, tt := range tests {
+		buf := &bytes.Buffer{}
+		fancyLogger := &fakeFancyLogger{buf: buf}
+		tt.setLoggerFunc(fancyLogger)
+		tt.logFunc("[test]", "Hello", "World!")
+
+		actual := buf.String()
+		suffix := "[test] [Hello World!]\n"
+
+		if !strings.HasSuffix(actual, suffix) {
+			t.Errorf("Expected %s to end with %s", actual, suffix)
+		}
+		if fancyLogger.lastCalled != tt.shouldCall {
+			t.Errorf("Expected call to %s, got %s", tt.shouldCall, fancyLogger.lastCalled)
+		}
+	}
+}
+
 func TestDebugDisabled(t *testing.T) {
 	EnableDebugLogging = false