Moving project to a temp directory to perform git mutations

Author: navhits

semgrep_precommit/main.py

@@ -25,15 +25,22 @@ def main() -> None:
     for argument in list(arguments):
         if is_file(argument):
             arguments.remove(argument)
-
+    temp_dir = make_tmp_dir()
+    is_copied = copy_to_tmp(dest=temp_dir, src="/src")
+    if not is_copied:
+        print("Failed to copy files to temporary directory")
+        sys.exit(1)
+    else:
+        add_safe_git_dir(temp_dir.name)
     current_commit, commit_before_current = None, None
-    is_commit = commit_staged_files()
+    is_commit = commit_staged_files(temp_dir.name)
     if is_commit:
-        current_commit, commit_before_current = get_last_two_commit_ids()
+        current_commit, commit_before_current = get_last_two_commit_ids(temp_dir.name)
         os.environ["SEMGREP_BASELINE_REF"] = commit_before_current
     exit_code = run_semgrep(arguments)
     if is_commit:
-        soft_reset_to_commit(commit_before_current)
+        soft_reset_to_commit(temp_dir.name, commit_before_current)
+    temp_dir.cleanup()
     sys.exit(exit_code)
 
 if __name__ == "__main__":

semgrep_precommit/utils.py

@@ -1,8 +1,21 @@
 import os
+import shutil
 import subprocess
+import tempfile
 import typing
 
 
+def add_safe_git_dir(path: str) -> None:
+    """add_safe_git_dir marks the directory safe for git
+
+    Args:
+        path (str): The path to directory
+    """
+    try:
+        subprocess.run(["git", "config", "--add", "safe.directory", path], cwd=path)
+    except Exception:
+        return
+
 def is_file(filename: str) -> bool:
     """is_file checks if a given value is valid a file.
 
@@ -16,10 +29,11 @@ def is_file(filename: str) -> bool:
         return True
     return False
 
-def commit_staged_files(message: str = "Dummy commit by semgrep pre-commit hook") -> bool:
+def commit_staged_files(path: str, message: str = "Dummy commit by semgrep pre-commit hook") -> bool:
     """commit_staged_files commits all staged files with a given message.
 
     Args:
+        path (str): The path to the git repository.
         message (str, optional): A commit message. 
         Defaults to "Dummy commit by semgrep pre-commit hook".
 
@@ -28,30 +42,34 @@ def commit_staged_files(message: str = "Dummy commit by semgrep pre-commit hook"
     """
     try:
         # We use -n to avoid running the pre-commit hook again
-        subprocess.run(["git", "commit", "-n", "-m", message], stdout=subprocess.DEVNULL)
+        subprocess.run(["git", "commit", "-n", "-m", message], stdout=subprocess.DEVNULL,
+                       cwd=path)
     except Exception:
         return False
     else:
         return True
 
-def get_last_two_commit_ids() -> typing.Tuple[str | None, str | None]:
+def get_last_two_commit_ids(path: str) -> typing.Tuple[str | None, str | None]:
     """get_last_two_commit_ids returns the last two commit IDs of the current branch
 
+    Args:
+        path (str): The path to the git repository.
+
     Returns:
         typing.Tuple[str | None, str | None]: The last two commit IDs
     """
     commit_ids = None, None
     try:
         proc = subprocess.run(["git", "log", "--pretty=format:%H", "-n", "2"], 
-                              capture_output=True)
+                              capture_output=True, cwd=path)
         if proc.returncode == 0:
             commit_ids = proc.stdout.decode("utf-8").strip("\n").split("\n")
     except Exception:
         return None, None
     else:
         return tuple(commit_ids)
 
-def soft_reset_to_commit(commit_id: str) -> bool:
+def soft_reset_to_commit(path: str, commit_id: str) -> bool:
     """git_soft_reset_to_commit performs a soft reset to the previous commit
 
     Args:
@@ -61,8 +79,39 @@ def soft_reset_to_commit(commit_id: str) -> bool:
         bool: True if the soft reset was successful, False otherwise
     """
     try:
-        subprocess.run(["git", "reset", "--soft", commit_id], stdout=subprocess.DEVNULL)
+        subprocess.run(["git", "reset", "--soft", commit_id], stdout=subprocess.DEVNULL, cwd=path)
     except Exception:
         return False
     else:
         return True
+
+def make_tmp_dir() -> tempfile.TemporaryDirectory:
+    """
+    make_tmp_dir: Creates a temporary directory
+
+    Returns:
+        tempfile.TemporaryDirectory: The tempfile.TemporaryDirectory object
+    """
+    temp_dir = tempfile.TemporaryDirectory()
+    return temp_dir
+
+def copy_to_tmp(dest: str | tempfile.TemporaryDirectory, src: str = "/src") -> bool:
+    """
+    copy_to_tmp: Copies the contents of the src directory to the dest directory
+
+    Args:
+        dest (str | tempfile.TemporaryDirectory): A tempfile.TemporaryDirectory object or a string
+        src (str, optional): The source path to be copied. Defaults to "/src".
+
+    Returns:
+        bool: True if the copy was successful, False otherwise
+    """
+    dest_name = dest
+    if isinstance(dest_name, tempfile.TemporaryDirectory):
+        dest_name = dest.name
+
+    try:
+        shutil.copytree(src, dest_name, dirs_exist_ok=True)
+        return True
+    except Exception:
+        return False