extract header from code

.cross_sync/generate.py

@@ -23,11 +23,27 @@
 """
 
 
+def extract_header_comments(file_path) -> str:
+ """
+ Extract the file header. Header is defined as the top-level
+ comments before any code or imports
+ """
+ header = []
+ with open(file_path, "r") as f:
+ for line in f:
+ if line.startswith("#") or line.strip() == "":
+ header.append(line)
+ else:
+ break
+ return "".join(header)
+
+
 class CrossSyncOutputFile:
 
- def __init__(self, file_path: str, ast_tree):
- self.file_path = file_path
+ def __init__(self, output_path: str, ast_tree, header: str | None = None):
+ self.output_path = output_path
  self.tree = ast_tree
+ self.header = header or ""
 
  def render(self, with_black=True, save_to_disk: bool = False) -> str:
  """
@@ -37,24 +53,7 @@ def render(self, with_black=True, save_to_disk: bool = False) -> str:
  with_black: whether to run the output through black before returning
  save_to_disk: whether to write the output to the file path
  """
- header = (
- "# Copyright 2024 Google LLC\n"
- "#\n"
- '# Licensed under the Apache License, Version 2.0 (the "License");\n'
- "# you may not use this file except in compliance with the License.\n"
- "# You may obtain a copy of the License at\n"
- "#\n"
- "# http://www.apache.org/licenses/LICENSE-2.0\n"
- "#\n"
- "# Unless required by applicable law or agreed to in writing, software\n"
- '# distributed under the License is distributed on an "AS IS" BASIS,\n'
- "# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.\n"
- "# See the License for the specific language governing permissions and\n"
- "# limitations under the License.\n"
- "#\n"
- "# This file is automatically generated by CrossSync. Do not edit manually.\n"
- )
- full_str = header + ast.unparse(self.tree)
+ full_str = self.header + ast.unparse(self.tree)
  if with_black:
  import black # type: ignore
  import autoflake # type: ignore
@@ -65,8 +64,8 @@ def render(self, with_black=True, save_to_disk: bool = False) -> str:
  )
  if save_to_disk:
  import os
- os.makedirs(os.path.dirname(self.file_path), exist_ok=True)
- with open(self.file_path, "w") as f:
+ os.makedirs(os.path.dirname(self.output_path), exist_ok=True)
+ with open(self.output_path, "w") as f:
  f.write(full_str)
  return full_str
 
@@ -87,7 +86,8 @@ def convert_files_in_dir(directory: str) -> set[CrossSyncOutputFile]:
  if output_path is not None:
  # contains __CROSS_SYNC_OUTPUT__ annotation
  converted_tree = file_transformer.visit(ast_tree)
- artifacts.add(CrossSyncOutputFile(output_path, converted_tree))
+ header = extract_header_comments(file_path)
+ artifacts.add(CrossSyncOutputFile(output_path, converted_tree, header))
  # return set of output artifacts
  return artifacts