add func PathBase

Author: cdvelop

README.md

@@ -87,6 +87,7 @@ Replace common `strings` package functions with TinyString equivalents:
 | `strings.TrimSuffix()` | `Convert(s).TrimSuffix(suffix).String()` |
 | `strings.HasPrefix()` | `HasPrefix(s, prefix)` |
 | `strings.HasSuffix()` | `HasSuffix(s, suffix)` |
+| `filepath.Base()` | `PathBase(path)` |
 
 #### Other String Transformations
 
@@ -125,6 +126,13 @@ if pos >= 0 {
 //             Contains(s, substr)         // ✅ Correct
 //             LastIndex(s, substr)        // ✅ Correct
 
+
+// PathBase
+PathBase("/a/b/c.txt") // -> "c.txt"
+PathBase("folder/file.txt")   // -> "file.txt"
+PathBase("")           // -> "."
+PathBase("c:\file program\app.exe") // -> "app.exe"
+
 // Replace operations
 Convert("hello world").Replace("world", "Go").String() // out: "hello Go"
 Convert("test 123 test").Replace(123, 456).String()    // out: "test 456 test"

filepath.go

@@ -0,0 +1,60 @@
+package tinystring
+
+// PathBase returns the last element of path, similar to
+// filepath.Base from the Go standard library. It treats
+// trailing slashes specially ("/a/b/" -> "b") and preserves
+// a single root slash ("/" -> "/"). An empty path returns ".".
+//
+// The implementation uses tinystring helpers (HasSuffix and Index)
+// to avoid importing the standard library and keep the function
+// minimal and TinyGo-friendly.
+//
+// Examples:
+//
+//		PathBase("/a/b/c.txt") // -> "c.txt"
+//		PathBase("folder/file.txt")   // -> "file.txt"
+//		PathBase("")           // -> "."
+//	 PathBase("c:\file program\app.exe") // -> "app.exe"
+func PathBase(path string) string {
+	if path == "" {
+		return "."
+	}
+
+	// prefer backslash if present
+	sep := byte('/')
+	if Index(path, "\\") != -1 {
+		sep = '\\'
+	}
+
+	// windows drive root like "C:\" or with only extra separators -> return "\\"
+	if sep == '\\' && len(path) >= 2 && path[1] == ':' {
+		onlySep := true
+		for i := 2; i < len(path); i++ {
+			if path[i] != '\\' && path[i] != '/' {
+				onlySep = false
+				break
+			}
+		}
+		if onlySep {
+			return "\\"
+		}
+	}
+
+	// trim trailing separators
+	for len(path) > 1 && path[len(path)-1] == sep {
+		path = path[:len(path)-1]
+	}
+
+	// if path reduced to a single root separator, return it
+	if len(path) == 1 && (path[0] == '/' || path[0] == '\\') {
+		return path
+	}
+
+	// search from end for last separator
+	for i := len(path) - 1; i >= 0; i-- {
+		if path[i] == sep {
+			return path[i+1:]
+		}
+	}
+	return path
+}

filepath_test.go

@@ -0,0 +1,59 @@
+package tinystring
+
+import "testing"
+
+func TestFilePathBase(t *testing.T) {
+	tests := []struct {
+		path string
+		want string
+	}{
+		{"", "."},
+		{"/", "/"},
+		{"///", "/"},
+		{"a", "a"},
+		{"a/b", "b"},
+		{"a/b/", "b"},
+		{"/a/b/c", "c"},
+		{"/a/b/c/", "c"},
+		{"///a", "a"},
+		{"a//b", "b"},
+		{".", "."},
+		{"..", ".."},
+		{"no/slash_at_end", "slash_at_end"},
+		// file extension cases
+		{"file.txt", "file.txt"},
+		{"dir/file.txt", "file.txt"},
+		{"/path/to/archive.tar.gz", "archive.tar.gz"},
+		{"dir/.hidden", ".hidden"},
+		{"a/b.c/d.e", "d.e"},
+		{"/trailing/.bashrc/", ".bashrc"},
+	}
+
+	for _, tc := range tests {
+		t.Run(tc.path, func(t *testing.T) {
+			got := PathBase(tc.path)
+			if got != tc.want {
+				t.Fatalf("FilePathBase(%q) = %q; want %q", tc.path, got, tc.want)
+			}
+		})
+	}
+}
+
+func TestPathBaseWindows(t *testing.T) {
+	tests := []struct{ path, want string }{
+		{`C:\`, `\`},
+		{`C:\file.exe`, `file.exe`},
+		{`C:\Program Files\App\app.exe`, `app.exe`},
+		{`C:\dir\\sub\file.txt`, `file.txt`},
+		{`\\server\share\file`, `file`},
+	}
+
+	for _, tc := range tests {
+		t.Run(tc.path, func(t *testing.T) {
+			got := PathBase(tc.path)
+			if got != tc.want {
+				t.Fatalf("PathBase(%q) = %q; want %q", tc.path, got, tc.want)
+			}
+		})
+	}
+}