link-headers: use pathlib consistenly and fix type errors

Author: Mic92

maintainers/link-headers

@@ -13,53 +13,59 @@
 # `src/.gitignore` so that the symlinks are not accidentally committed
 # by mistake.
 
-import os
 from pathlib import Path
 import subprocess
 
-# Path to the source directory
-SRC_DIR = Path("src")
 
-# Get header files from git
-result = subprocess.run(
-    ["git", "-C", str(SRC_DIR), "ls-files", "*/include/nix/**.hh"],
-    text=True, capture_output=True, check=True
-)
-header_files = result.stdout.strip().split("\n")
-header_files.sort()
+def main() -> None:
+    # Path to the source directory
+    SRC_DIR = Path("src")
 
-# Build header pairs
-header_pairs = []
-for file in header_files:
-    project, header = file.split("/include/nix/", 1)
-    header_pairs.append((Path(project), Path(header)))
+    # Get header files from git
+    result = subprocess.run(
+        ["git", "-C", str(SRC_DIR), "ls-files", "*/include/nix/**.hh"],
+        text=True,
+        capture_output=True,
+        check=True,
+    )
+    header_files = result.stdout.strip().split("\n")
+    header_files.sort()
+
+    # Build header pairs
+    header_pairs = []
+    for file_str in header_files:
+        project_str, header_str = file_str.split("/include/nix/", 1)
+        header_pairs.append((Path(project_str), Path(header_str)))
+
+    # Generate .gitignore file
+    gitignore_path = SRC_DIR / ".gitignore"
+    with gitignore_path.open("w") as gitignore:
+        gitignore.write("# DO NOT EDIT! Autogenerated\n")
+        gitignore.write(
+            "# Symlinks for headers to be next to sources for development\n"
+        )
+        gitignore.write('# Run "maintainers/link-headers" to regenerate\n\n')
 
-# Generate .gitignore file
-gitignore_path = SRC_DIR / ".gitignore"
-with open(gitignore_path, "w") as gitignore:
-    gitignore.write("# DO NOT EDIT! Autogenerated\n")
-    gitignore.write("# Symlinks for headers to be next to sources for development\n")
-    gitignore.write('# Run "maintainers/link-headers" to regenerate\n\n')
+        for project, header in header_pairs:
+            gitignore.write(f"/{project / header}\n")
 
     for project, header in header_pairs:
-        gitignore.write(f"/{project / header}\n")
+        # Reconstruct the full path (relative to SRC_DIR) to the header file.
+        file = project / "include" / "nix" / header
 
-for project, header in header_pairs:
-    # Reconstruct the full path (relative to SRC_DIR) to the header file.
-    file = project / "include" / "nix" / header
+        # The symlink should be created at "project/header", i.e. next to the project's sources.
+        link = project / header
 
-    # The symlink should be created at "project/header", i.e. next to the project's sources.
-    link = project / header
+        # Compute a relative path from the symlink's parent directory to the actual header file.
+        relative_source = (SRC_DIR / file).relative_to(SRC_DIR / link.parent)
+
+        # Create the symbolic link.
+        full_link_path = SRC_DIR / link
+        full_link_path.parent.mkdir(parents=True, exist_ok=True)
+        if full_link_path.is_symlink():
+            full_link_path.unlink()
+        full_link_path.symlink_to(relative_source)
 
-    # Compute a relative path from the symlink's parent directory to the actual header file.
-    relative_source = os.path.relpath(
-        SRC_DIR / file,
-        SRC_DIR / link.parent
-    )
 
-    # Create the symbolic link.
-    full_link_path = SRC_DIR / link
-    os.makedirs(full_link_path.parent, exist_ok=True)
-    if os.path.islink(full_link_path):
-        os.remove(full_link_path)
-    os.symlink(relative_source, full_link_path)
+if __name__ == "__main__":
+    main()