Add script and pre-commit hook for copyright (#13)

Author: blms

.pre-commit-config.yaml

@@ -1,3 +1,6 @@
+# Copyright 2025 Center for Digital Humanities, Princeton University
+# SPDX-License-Identifier: Apache-2.0
+
 repos:
   - repo: https://github.com/astral-sh/ruff-pre-commit
     # Ruff version.
@@ -8,3 +11,9 @@ repos:
         args: [ --fix ]
       # Run the formatter.
       - id: ruff-format
+  - repo: local
+    hooks:
+      - id: check-copyright
+        name: check-copyright
+        entry: python scripts/add_copyright.py --check
+        language: python

scripts/add_copyright.py

@@ -0,0 +1,85 @@
+# Copyright 2025 Center for Digital Humanities, Princeton University
+# SPDX-License-Identifier: Apache-2.0
+
+import argparse
+import sys
+import re
+from pathlib import Path
+
+# variables for adding copyright notice programmatically
+COPYRIGHT_YEAR = "2025"
+COPYRIGHT_HOLDER = "Center for Digital Humanities, Princeton University"
+COPYRIGHT_STATEMENT = f"Copyright {COPYRIGHT_YEAR} {COPYRIGHT_HOLDER}"
+SPDX_ID = "SPDX-License-Identifier: Apache-2.0"
+SUPPORTED_TYPES = [".py", ".yaml", ".yml", ".toml"]
+
+# regex to check if ANY copyright is present
+COPYRIGHT_RE = re.compile(r"^\s*#\s*[Cc]opyright", re.MULTILINE)
+
+# regex for existing emory copyright, keeping track of indentation
+EUL_RE = re.compile(r"^(\s*#\s*)Copyright [\d,]+ Emory University", re.MULTILINE)
+
+
+def main(arg_list=None):
+    """Add or check for copyright statements"""
+    parser = argparse.ArgumentParser()
+    parser.add_argument(
+        "--check",
+        action="store_true",
+        help="Check files for copyright notice",
+    )
+    parser.add_argument(
+        "filenames",
+        nargs="*",
+        help="Filenames (may use glob pattern) to check or modify",
+    )
+    args = parser.parse_args(arg_list)
+
+    check = args.check
+    needs_copyright = []
+
+    for filename in args.filenames:
+        path = Path(filename)
+        if (
+            not path.is_file()  # skip non-files
+            or path.name in ["lextab.py", "parsetab.py"]  # skip generated PLY files
+            or "schema_data" in path.parts  # skip schema_data/* (xml from elsewhere)
+            # skip test fixtures
+            or any("fixtures" in part for part in path.parts if "test" in path.parts)
+        ):
+            continue
+
+        try:
+            contents = path.read_text(encoding="utf-8")
+        except (UnicodeDecodeError, OSError):
+            # skip unreadable/binary files
+            continue
+
+        if not COPYRIGHT_RE.search(contents):
+            # missing copyright: add to pre-commit check failures
+            needs_copyright.append(filename)
+            if not check and path.suffix in SUPPORTED_TYPES:
+                # automatically add CDH copyright with SPDX identifier
+                new_contents = f"# {COPYRIGHT_STATEMENT}\n# {SPDX_ID}\n\n{contents}"
+                path.write_text(new_contents)
+        elif not check and EUL_RE.search(contents):
+            # has EUL copyright: add CDH copyright directly above
+            new_contents = EUL_RE.sub(
+                lambda m: f"{m.group(1)}{COPYRIGHT_STATEMENT}\n{m.group(0)}",
+                contents,
+            )
+            path.write_text(new_contents)
+
+    if check:
+        # use exit code to tell pre-commit success or failure
+        if needs_copyright:
+            print("The following files are missing a copyright notice:")
+            for f in needs_copyright:
+                print(f" - {f}")
+            sys.exit(1)
+        print("All modified files have copyright notices.")
+        sys.exit(0)
+
+
+if __name__ == "__main__":
+    main()