refactor: path resolution to separate file

internal/miro/path_resolution.go

@@ -0,0 +1,39 @@
+package miro
+
+import (
+	"fmt"
+	"os"
+	"path/filepath"
+	"strings"
+)
+
+func resolveRecordTarget(testDir, path string) (string, error) {
+	return resolvePathWithinTestDir(testDir, path, "record")
+}
+
+func resolvePathWithinTestDir(testDir, path, pathType string) (string, error) {
+	absTestDir, err := filepath.Abs(testDir)
+	if err != nil {
+		return "", fmt.Errorf("failed to resolve test directory path: %v", err)
+	}
+
+	absPath, err := filepath.Abs(path)
+	if err != nil {
+		return "", fmt.Errorf("failed to resolve %s path: %v", pathType, err)
+	}
+
+	relToTestDir, err := filepath.Rel(absTestDir, absPath)
+	if err == nil && isWithinBase(relToTestDir) {
+		return filepath.Join(absTestDir, relToTestDir), nil
+	}
+
+	if filepath.IsAbs(path) {
+		return "", fmt.Errorf("%s path %q must be inside test directory %q", pathType, path, absTestDir)
+	}
+
+	return filepath.Join(absTestDir, path), nil
+}
+
+func isWithinBase(rel string) bool {
+	return rel == "." || (rel != ".." && !strings.HasPrefix(rel, ".."+string(os.PathSeparator)))
+}