feat: loader logic

pkg/storage/fs/fs_test.go

@@ -172,13 +172,28 @@ func TestRawFileCRUDAndList(t *testing.T) {
 		t.Fatalf("write beta: %v", err)
 	}
 
-	alphaExists, err := s.FileExists("nested/alpha.txt")
+	alphaExists, alphaPath, err := s.FileExists("nested/alpha.txt")
 	if err != nil {
 		t.Fatalf("file exists: %v", err)
 	}
 	if !alphaExists {
 		t.Fatal("nested/alpha.txt should exist")
 	}
+	wantAlphaPath := filepath.Join(s.storageRoot, "nested", "alpha.txt")
+	if alphaPath != wantAlphaPath {
+		t.Fatalf("file path = %q, want %q", alphaPath, wantAlphaPath)
+	}
+
+	missingExists, missingPath, err := s.FileExists("missing.txt")
+	if err != nil {
+		t.Fatalf("missing file exists: %v", err)
+	}
+	if missingExists {
+		t.Fatal("missing.txt should not exist")
+	}
+	if missingPath != "" {
+		t.Fatalf("missing file path = %q, want empty string", missingPath)
+	}
 
 	alphaData, err := s.ReadFile("nested/alpha.txt")
 	if err != nil {