Merge pull request #19170 from callthingsoff/simplify_MergeOutputPaths

client/pkg/logutil: simplify MergeOutputPaths function

client/pkg/logutil/zap.go

@@ -15,7 +15,7 @@
 package logutil
 
 import (
-	"sort"
+	"slices"
 	"time"
 
 	"go.uber.org/zap"
@@ -72,37 +72,22 @@ var DefaultZapLoggerConfig = zap.Config{
 
 // MergeOutputPaths merges logging output paths, resolving conflicts.
 func MergeOutputPaths(cfg zap.Config) zap.Config {
-	outputs := make(map[string]struct{})
-	for _, v := range cfg.OutputPaths {
-		outputs[v] = struct{}{}
-	}
-	outputSlice := make([]string, 0)
-	if _, ok := outputs["/dev/null"]; ok {
-		// "/dev/null" to discard all
-		outputSlice = []string{"/dev/null"}
-	} else {
-		for k := range outputs {
-			outputSlice = append(outputSlice, k)
-		}
-	}
-	cfg.OutputPaths = outputSlice
-	sort.Strings(cfg.OutputPaths)
+	cfg.OutputPaths = mergePaths(cfg.OutputPaths)
+	cfg.ErrorOutputPaths = mergePaths(cfg.ErrorOutputPaths)
+	return cfg
+}
 
-	errOutputs := make(map[string]struct{})
-	for _, v := range cfg.ErrorOutputPaths {
-		errOutputs[v] = struct{}{}
+func mergePaths(old []string) []string {
+	if len(old) == 0 {
+		// the original implementation ensures the result is non-nil
+		return []string{}
 	}
-	errOutputSlice := make([]string, 0)
-	if _, ok := errOutputs["/dev/null"]; ok {
-		// "/dev/null" to discard all
-		errOutputSlice = []string{"/dev/null"}
-	} else {
-		for k := range errOutputs {
-			errOutputSlice = append(errOutputSlice, k)
-		}
+	// use "/dev/null" to discard all
+	if slices.Contains(old, "/dev/null") {
+		return []string{"/dev/null"}
 	}
-	cfg.ErrorOutputPaths = errOutputSlice
-	sort.Strings(cfg.ErrorOutputPaths)
-
-	return cfg
+	// clone a new one; don't modify the original, in case it matters.
+	dup := slices.Clone(old)
+	slices.Sort(dup)
+	return slices.Compact(dup)
 }