2 files changed, 65 insertions, 0 deletions
diff --git a/util/pathutil/pathutil.go b/util/pathutil/pathutil.go
new file mode 100644
index 000000000..6b3728d9f
--- /dev/null
+++ b/util/pathutil/pathutil.go
@@ -0,0 +1,28 @@
+// Copyright (c) Tailscale Inc & AUTHORS
+// SPDX-License-Identifier: BSD-3-Clause
+
+// package pathutil provides utility functions for working with URL paths.
+package pathutil
+
+import (
+	"path"
+	"strings"
+)
+
+const (
+	sepString       = "/"
+	sepStringAndDot = "/."
+	sep             = '/'
+)
+
+func Split(p string) []string {
+	return strings.Split(strings.Trim(path.Clean(p), sepStringAndDot), sepString)
+}
+
+func Join(parts ...string) string {
+	return sepString + strings.Join(parts, sepString)
+}
+
+func IsRoot(path string) bool {
+	return len(path) == 0 || len(path) == 1 && path[0] == sep
+}
diff --git a/util/pathutil/pathutil_test.go b/util/pathutil/pathutil_test.go
new file mode 100644
index 000000000..7ecc3787c
--- /dev/null
+++ b/util/pathutil/pathutil_test.go
@@ -0,0 +1,37 @@
+// Copyright (c) Tailscale Inc & AUTHORS
+// SPDX-License-Identifier: BSD-3-Clause
+
+package pathutil
+
+import (
+	"reflect"
+	"testing"
+)
+
+func TestSplit(t *testing.T) {
+	tests := []struct {
+		path string
+		want []string
+	}{
+		{"", []string{""}},
+		{"/", []string{""}},
+		{"//", []string{""}},
+		{"a", []string{"a"}},
+		{"/a", []string{"a"}},
+		{"a/", []string{"a"}},
+		{"/a/", []string{"a"}},
+		{"a/b", []string{"a", "b"}},
+		{"/a/b", []string{"a", "b"}},
+		{"a/b/", []string{"a", "b"}},
+		{"/a/b/", []string{"a", "b"}},
+		{"/a/../b", []string{"b"}},
+	}
+	for _, tt := range tests {
+		t.Run(tt.path, func(t *testing.T) {
+			if got := Split(tt.path); !reflect.DeepEqual(tt.want, got) {
+				t.Errorf("Split(%q) = %v; want %v", tt.path, got, tt.want)
+			}
+		})
+	}
+
+}