Add methods for logging with level as argument (#1406)

Adding generic `Log`, `Logf`, `Logw` and `Logln` methods to Sugared
logger.

When I need to do a wrapper around Zap logger to pass that into 3rd
party library for unifying logging, it might come handy to use
zap.Log(level, ...) instead of switch or if-else if chain.

However, now I need to do a same wrapper but with Sugared logger. And
that doesn't support general Log method.

More description in #1405

sugar.go

@@ -137,6 +137,12 @@ func (s *SugaredLogger) Level() zapcore.Level {
 	return zapcore.LevelOf(s.base.core)
 }
 
+// Log logs the provided arguments at provided level.
+// Spaces are added between arguments when neither is a string.
+func (s *SugaredLogger) Log(lvl zapcore.Level, args ...interface{}) {
+	s.log(lvl, "", args, nil)
+}
+
 // Debug logs the provided arguments at [DebugLevel].
 // Spaces are added between arguments when neither is a string.
 func (s *SugaredLogger) Debug(args ...interface{}) {
@@ -180,6 +186,12 @@ func (s *SugaredLogger) Fatal(args ...interface{}) {
 	s.log(FatalLevel, "", args, nil)
 }
 
+// Logf formats the message according to the format specifier
+// and logs it at provided level.
+func (s *SugaredLogger) Logf(lvl zapcore.Level, template string, args ...interface{}) {
+	s.log(lvl, template, args, nil)
+}
+
 // Debugf formats the message according to the format specifier
 // and logs it at [DebugLevel].
 func (s *SugaredLogger) Debugf(template string, args ...interface{}) {
@@ -223,6 +235,12 @@ func (s *SugaredLogger) Fatalf(template string, args ...interface{}) {
 	s.log(FatalLevel, template, args, nil)
 }
 
+// Logw logs a message with some additional context. The variadic key-value
+// pairs are treated as they are in With.
+func (s *SugaredLogger) Logw(lvl zapcore.Level, msg string, keysAndValues ...interface{}) {
+	s.log(lvl, msg, nil, keysAndValues)
+}
+
 // Debugw logs a message with some additional context. The variadic key-value
 // pairs are treated as they are in With.
 //
@@ -270,6 +288,12 @@ func (s *SugaredLogger) Fatalw(msg string, keysAndValues ...interface{}) {
 	s.log(FatalLevel, msg, nil, keysAndValues)
 }
 
+// Logln logs a message at provided level.
+// Spaces are always added between arguments.
+func (s *SugaredLogger) Logln(lvl zapcore.Level, args ...interface{}) {
+	s.logln(lvl, args, nil)
+}
+
 // Debugln logs a message at [DebugLevel].
 // Spaces are always added between arguments.
 func (s *SugaredLogger) Debugln(args ...interface{}) {

sugar_test.go

@@ -311,9 +311,10 @@ func TestSugarStructuredLogging(t *testing.T) {
 			logger.With(context...).Warnw(tt.msg, extra...)
 			logger.With(context...).Errorw(tt.msg, extra...)
 			logger.With(context...).DPanicw(tt.msg, extra...)
+			logger.With(context...).Logw(WarnLevel, tt.msg, extra...)
 
-			expected := make([]observer.LoggedEntry, 5)
-			for i, lvl := range []zapcore.Level{DebugLevel, InfoLevel, WarnLevel, ErrorLevel, DPanicLevel} {
+			expected := make([]observer.LoggedEntry, 6)
+			for i, lvl := range []zapcore.Level{DebugLevel, InfoLevel, WarnLevel, ErrorLevel, DPanicLevel, WarnLevel} {
 				expected[i] = observer.LoggedEntry{
 					Entry:   zapcore.Entry{Message: tt.expectMsg, Level: lvl},
 					Context: expectedFields,
@@ -343,9 +344,10 @@ func TestSugarConcatenatingLogging(t *testing.T) {
 			logger.With(context...).Warn(tt.args...)
 			logger.With(context...).Error(tt.args...)
 			logger.With(context...).DPanic(tt.args...)
+			logger.With(context...).Log(InfoLevel, tt.args...)
 
-			expected := make([]observer.LoggedEntry, 5)
-			for i, lvl := range []zapcore.Level{DebugLevel, InfoLevel, WarnLevel, ErrorLevel, DPanicLevel} {
+			expected := make([]observer.LoggedEntry, 6)
+			for i, lvl := range []zapcore.Level{DebugLevel, InfoLevel, WarnLevel, ErrorLevel, DPanicLevel, InfoLevel} {
 				expected[i] = observer.LoggedEntry{
 					Entry:   zapcore.Entry{Message: tt.expect, Level: lvl},
 					Context: expectedFields,
@@ -379,9 +381,10 @@ func TestSugarTemplatedLogging(t *testing.T) {
 			logger.With(context...).Warnf(tt.format, tt.args...)
 			logger.With(context...).Errorf(tt.format, tt.args...)
 			logger.With(context...).DPanicf(tt.format, tt.args...)
+			logger.With(context...).Logf(ErrorLevel, tt.format, tt.args...)
 
-			expected := make([]observer.LoggedEntry, 5)
-			for i, lvl := range []zapcore.Level{DebugLevel, InfoLevel, WarnLevel, ErrorLevel, DPanicLevel} {
+			expected := make([]observer.LoggedEntry, 6)
+			for i, lvl := range []zapcore.Level{DebugLevel, InfoLevel, WarnLevel, ErrorLevel, DPanicLevel, ErrorLevel} {
 				expected[i] = observer.LoggedEntry{
 					Entry:   zapcore.Entry{Message: tt.expect, Level: lvl},
 					Context: expectedFields,
@@ -415,9 +418,10 @@ func TestSugarLnLogging(t *testing.T) {
 			logger.With(context...).Warnln(tt.args...)
 			logger.With(context...).Errorln(tt.args...)
 			logger.With(context...).DPanicln(tt.args...)
+			logger.With(context...).Logln(InfoLevel, tt.args...)
 
-			expected := make([]observer.LoggedEntry, 5)
-			for i, lvl := range []zapcore.Level{DebugLevel, InfoLevel, WarnLevel, ErrorLevel, DPanicLevel} {
+			expected := make([]observer.LoggedEntry, 6)
+			for i, lvl := range []zapcore.Level{DebugLevel, InfoLevel, WarnLevel, ErrorLevel, DPanicLevel, InfoLevel} {
 				expected[i] = observer.LoggedEntry{
 					Entry:   zapcore.Entry{Message: tt.expect, Level: lvl},
 					Context: expectedFields,