fix: implement correct FilenameOverflow calculation

go.mod

@@ -7,6 +7,7 @@ retract v1.0.0
 require (
 	github.com/cheggaaa/pb/v3 v3.1.5
 	github.com/fatih/color v1.17.0
+	github.com/rivo/uniseg v0.4.7
 	github.com/stretchr/testify v1.9.0
 	github.com/urfave/cli/v2 v2.27.2
 	golang.org/x/crypto v0.23.0
@@ -21,7 +22,6 @@ require (
 	github.com/mattn/go-isatty v0.0.20 // indirect
 	github.com/mattn/go-runewidth v0.0.15 // indirect
 	github.com/pmezard/go-difflib v1.0.0 // indirect
-	github.com/rivo/uniseg v0.4.7 // indirect
 	github.com/russross/blackfriday/v2 v2.1.0 // indirect
 	github.com/xrash/smetrics v0.0.0-20240312152122-5f08fbb34913 // indirect
 	golang.org/x/sys v0.20.0 // indirect

pathutils/pathutils.go

@@ -5,6 +5,8 @@ import (
 	"fmt"
 	"os"
 	"path/filepath"
+
+	"github.com/rivo/uniseg"
 )
 
 // Checks whenever given slice of strings contains duplicates.
@@ -34,14 +36,19 @@ func hasDuplicateFilenames(s []string) bool {
 }
 
 func FilenameOverflow(s string, n int) string {
-	r := []rune(s)
-	if len(r) < n {
+	charCount := uniseg.GraphemeClusterCount(s)
+	if charCount < n {
 		return s
 	}
-	return string(r[:n]) + "..."
+	gr := uniseg.NewGraphemes(s)
+	for range n {
+		gr.Next()
+	}
+	_, to := gr.Positions()
+	return s[:to] + "..."
 }
 
-// Cleans given paths and ouputDir and checks for duplicates.
+// Cleans given paths and ouputDir (which is also assumed to be a path) and checks for duplicates.
 // Also checks for duplicate filenames if outputDir is not empty.
 // Returns cleaned paths or error if any of the checks failed.
 func CleanAndCheckPaths(paths []string, outputDir string) ([]string, string, error) {