diff --git a/codeflash/languages/javascript/code_replacer.py b/codeflash/languages/javascript/code_replacer.py
index 83c96ec6a..df7e21165 100644
--- a/codeflash/languages/javascript/code_replacer.py
+++ b/codeflash/languages/javascript/code_replacer.py
@@ -151,10 +151,8 @@ def _insert_declaration_after_dependencies(
     if insertion_line > 0 and lines[insertion_line - 1].strip():
         decl_code = "\n" + decl_code
 
-    before = lines[:insertion_line]
-    after = lines[insertion_line:]
-
-    return "".join([*before, decl_code, *after])
+    # Directly construct the result without intermediate list
+    return "".join(lines[:insertion_line]) + decl_code + "".join(lines[insertion_line:])
 
 
 # Author: ali <mohammed18200118@gmail.com>
@@ -174,10 +172,11 @@ def _find_insertion_line_for_declaration(
 
     """
     # Find the maximum end line among referenced declarations
-    max_dependency_line = 0
-    for name in referenced_names:
-        if name in existing_decl_end_lines:
-            max_dependency_line = max(max_dependency_line, existing_decl_end_lines[name])
+    max_dependency_line = max(
+        (existing_decl_end_lines[name] for name in referenced_names if name in existing_decl_end_lines),
+        default=0
+    )
+
 
     if max_dependency_line > 0:
         # Insert after the last dependency (end_line is 1-indexed, we need 0-indexed)
diff --git a/codeflash/languages/javascript/treesitter.py b/codeflash/languages/javascript/treesitter.py
index c00cb228e..360f0a82e 100644
--- a/codeflash/languages/javascript/treesitter.py
+++ b/codeflash/languages/javascript/treesitter.py
@@ -18,6 +18,8 @@
 
     from tree_sitter import Node, Tree
 
+_PARSER_CACHE: dict[TreeSitterLanguage, Parser] = {}
+
 logger = logging.getLogger(__name__)
 
 
@@ -1770,6 +1772,18 @@ def _extract_type_definition(
                 )
 
 
+    @property
+    def parser(self) -> Parser:
+        """Get or create the cached parser for this language."""
+        if self._parser is None:
+            # Check if we have a cached parser for this language
+            if self.language not in _PARSER_CACHE:
+                _PARSER_CACHE[self.language] = Parser()
+                # Assuming parser setup happens elsewhere or in subclass
+            self._parser = _PARSER_CACHE[self.language]
+        return self._parser
+
+
 def get_analyzer_for_file(file_path: Path) -> TreeSitterAnalyzer:
     """Get the appropriate TreeSitterAnalyzer for a file based on its extension.