Prepare Sandwich Hime v1 release candidate source

internal/testpath/tempdir.go

@@ -0,0 +1,36 @@
+// SPDX-License-Identifier: AGPL-3.0-only
+
+// Package testpath provides filesystem helpers for tests that exercise
+// Hime-san's deliberate symlink boundaries.
+package testpath
+
+import (
+	"os"
+	"path/filepath"
+	"testing"
+)
+
+// TempDir returns the physical path to a fresh directory owned by the test.
+//
+// macOS commonly exposes its temporary directory through /var even though
+// /var is a root-owned system symlink to /private/var. Resolving a directory
+// immediately after testing.TB creates it keeps tests portable without
+// teaching production path validation to follow user-controlled symlinks.
+func TempDir(t testing.TB) string {
+	t.Helper()
+
+	directory := t.TempDir()
+	resolved, err := filepath.EvalSymlinks(directory)
+	if err != nil {
+		t.Fatalf("resolve test temporary directory: %v", err)
+	}
+	resolved = filepath.Clean(resolved)
+	info, err := os.Lstat(resolved)
+	if err != nil {
+		t.Fatalf("inspect resolved test temporary directory: %v", err)
+	}
+	if !info.IsDir() || info.Mode()&os.ModeSymlink != 0 {
+		t.Fatalf("resolved test temporary directory is not a physical directory: %s", resolved)
+	}
+	return resolved
+}