fix(zapgrpc): add WithVerbosity for correct grpclog V() semantics

zapgrpc/zapgrpc.go

@@ -72,6 +72,15 @@ func WithDebug() Option {
 	})
 }
 
+// WithVerbosity configures a Logger to use the given verbosity level for V() calls.
+// By default, V() uses zap's severity levels instead (Info, Warn, Error, Fatal).
+func WithVerbosity(verbosity int) Option {
+	return optionFunc(func(logger *Logger) {
+		logger.useVerbosity = true
+		logger.verbosity = verbosity
+	})
+}
+
 // withWarn redirects the fatal level to the warn level, which makes testing
 // easier. This is intentionally unexported.
 func withWarn() Option {
@@ -140,8 +149,8 @@ type Logger struct {
 	levelEnabler zapcore.LevelEnabler
 	print        *printer
 	fatal        *printer
-	// printToDebug bool
-	// fatalToWarn  bool
+	useVerbosity bool
+	verbosity    int
 }
 
 // Print implements grpclog.Logger.
@@ -233,6 +242,9 @@ func (l *Logger) Fatalf(format string, args ...interface{}) {
 
 // V implements grpclog.LoggerV2.
 func (l *Logger) V(level int) bool {
+	if l.useVerbosity {
+		return level <= l.verbosity
+	}
 	return l.levelEnabler.Enabled(_grpcToZapLevel[level])
 }
 

zapgrpc/zapgrpc_test.go

@@ -221,7 +221,17 @@ func checkLevel(
 	expectedBool bool,
 	f func(*Logger) bool,
 ) {
-	withLogger(enab, nil, func(logger *Logger, observedLogs *observer.ObservedLogs) {
+	checkLevelOpts(t, enab, nil, expectedBool, f)
+}
+
+func checkLevelOpts(
+	t testing.TB,
+	enab zapcore.LevelEnabler,
+	opts []Option,
+	expectedBool bool,
+	f func(*Logger) bool,
+) {
+	withLogger(enab, opts, func(logger *Logger, observedLogs *observer.ObservedLogs) {
 		actualBool := f(logger)
 		if expectedBool {
 			require.True(t, actualBool)
@@ -231,6 +241,47 @@ func checkLevel(
 	})
 }
 
+func TestLoggerVWithVerbosity(t *testing.T) {
+	tests := []struct {
+		verbosity    int
+		grpcEnabled  []int
+		grpcDisabled []int
+	}{
+		{
+			verbosity:    0,
+			grpcEnabled:  []int{0, -1},
+			grpcDisabled: []int{1, 2, 3},
+		},
+		{
+			verbosity:    2,
+			grpcEnabled:  []int{0, 1, 2},
+			grpcDisabled: []int{3, 4},
+		},
+	}
+
+	// Test that it behaves independently of the core zap level
+	zapLevels := []zapcore.Level{zapcore.DebugLevel, zapcore.InfoLevel, zapcore.ErrorLevel}
+
+	for _, zl := range zapLevels {
+		for _, tst := range tests {
+			for _, grpcLvl := range tst.grpcEnabled {
+				t.Run(fmt.Sprintf("level %s verbosity %d enabled %d", zl, tst.verbosity, grpcLvl), func(t *testing.T) {
+					checkLevelOpts(t, zl, []Option{WithVerbosity(tst.verbosity)}, true, func(logger *Logger) bool {
+						return logger.V(grpcLvl)
+					})
+				})
+			}
+			for _, grpcLvl := range tst.grpcDisabled {
+				t.Run(fmt.Sprintf("level %s verbosity %d disabled %d", zl, tst.verbosity, grpcLvl), func(t *testing.T) {
+					checkLevelOpts(t, zl, []Option{WithVerbosity(tst.verbosity)}, false, func(logger *Logger) bool {
+						return logger.V(grpcLvl)
+					})
+				})
+			}
+		}
+	}
+}
+
 func checkMessages(
 	t testing.TB,
 	enab zapcore.LevelEnabler,