Display notice when copyrighted file is copied or renamed (#52)

Also proposes requiring Python 3.10, since
rapidsai/build-planning#88 is being rolled
out.

Fixes #48

.github/workflows/run-tests.yaml

@@ -20,6 +20,6 @@ jobs:
           fetch-depth: 0
       - uses: actions/setup-python@v5
         with:
-          python-version: '3.9'
+          python-version: '3.10'
       - name: Build & Test
         run: ./ci/build-test.sh

pyproject.toml

@@ -30,7 +30,7 @@ classifiers = [
     "License :: OSI Approved :: Apache Software License",
     "Programming Language :: Python :: 3",
 ]
-requires-python = ">=3.9"
+requires-python = ">=3.10"
 dependencies = [
     "PyYAML",
     "bashlex",

src/rapids_pre_commit_hooks/copyright.py

@@ -23,7 +23,7 @@
 
 import git
 
-from .lint import Linter, LintMain
+from .lint import Linter, LintMain, LintWarning
 
 COPYRIGHT_RE: re.Pattern = re.compile(
     r"Copyright *(?:\(c\))? *(?P<years>(?P<first_year>\d{4})(-(?P<last_year>\d{4}))?),?"
@@ -59,21 +59,59 @@ def append_stripped(start: int, item: re.Match):
     return lines
 
 
+def add_copy_rename_note(
+    linter: Linter,
+    warning: LintWarning,
+    change_type: str,
+    old_filename: Optional[Union[str, os.PathLike[str]]],
+):
+    CHANGE_VERBS = {
+        "C": "copied",
+        "R": "renamed",
+    }
+    try:
+        change_verb = CHANGE_VERBS[change_type]
+    except KeyError:
+        pass
+    else:
+        warning.add_note(
+            (0, len(linter.content)),
+            f"file was {change_verb} from '{old_filename}' and is assumed to share "
+            "history with it",
+        )
+        warning.add_note(
+            (0, len(linter.content)),
+            "change file contents if you want its copyright dates to only be "
+            "determined by its own edit history",
+        )
+
+
 def apply_copyright_revert(
-    linter: Linter, old_match: re.Match, new_match: re.Match
+    linter: Linter,
+    change_type: str,
+    old_filename: Optional[Union[str, os.PathLike[str]]],
+    old_match: re.Match,
+    new_match: re.Match,
 ) -> None:
     if old_match.group("years") == new_match.group("years"):
         warning_pos = new_match.span()
     else:
         warning_pos = new_match.span("years")
-    linter.add_warning(
+    w = linter.add_warning(
         warning_pos,
         "copyright is not out of date and should not be updated",
-    ).add_replacement(new_match.span(), old_match.group())
+    )
+    w.add_replacement(new_match.span(), old_match.group())
+    add_copy_rename_note(linter, w, change_type, old_filename)
 
 
-def apply_copyright_update(linter: Linter, match: re.Match, year: int) -> None:
-    linter.add_warning(match.span("years"), "copyright is out of date").add_replacement(
+def apply_copyright_update(
+    linter: Linter,
+    match: re.Match,
+    year: int,
+) -> None:
+    w = linter.add_warning(match.span("years"), "copyright is out of date")
+    w.add_replacement(
         match.span(),
         COPYRIGHT_REPLACEMENT.format(
             first_year=match.group("first_year"),
@@ -82,7 +120,12 @@ def apply_copyright_update(linter: Linter, match: re.Match, year: int) -> None:
     )
 
 
-def apply_copyright_check(linter: Linter, old_content: Optional[str]) -> None:
+def apply_copyright_check(
+    linter: Linter,
+    change_type: str,
+    old_filename: Optional[Union[str, os.PathLike[str]]],
+    old_content: Optional[str],
+) -> None:
     if linter.content != old_content:
         current_year = datetime.datetime.now().year
         new_copyright_matches = match_copyright(linter.content)
@@ -97,7 +140,9 @@ def apply_copyright_check(linter: Linter, old_content: Optional[str]) -> None:
                 old_copyright_matches, new_copyright_matches
             ):
                 if old_match.group() != new_match.group():
-                    apply_copyright_revert(linter, old_match, new_match)
+                    apply_copyright_revert(
+                        linter, change_type, old_filename, old_match, new_match
+                    )
         elif new_copyright_matches:
             for match in new_copyright_matches:
                 if (
@@ -233,22 +278,24 @@ def try_get_ref(remote: "git.Remote") -> Optional["git.Reference"]:
 
 def get_changed_files(
     args: argparse.Namespace,
-) -> dict[Union[str, os.PathLike[str]], Optional["git.Blob"]]:
+) -> dict[Union[str, os.PathLike[str]], tuple[str, Optional["git.Blob"]]]:
     try:
         repo = git.Repo()
     except git.InvalidGitRepositoryError:
         return {
-            os.path.relpath(os.path.join(dirpath, filename), "."): None
+            os.path.relpath(os.path.join(dirpath, filename), "."): ("A", None)
             for dirpath, dirnames, filenames in os.walk(".")
             for filename in filenames
         }
 
-    changed_files: dict[Union[str, os.PathLike[str]], Optional["git.Blob"]] = {
-        f: None for f in repo.untracked_files
-    }
+    changed_files: dict[
+        Union[str, os.PathLike[str]], tuple[str, Optional["git.Blob"]]
+    ] = {f: ("A", None) for f in repo.untracked_files}
     target_branch_upstream_commit = get_target_branch_upstream_commit(repo, args)
     if target_branch_upstream_commit is None:
-        changed_files.update({blob.path: None for _, blob in repo.index.iter_blobs()})
+        changed_files.update(
+            {blob.path: ("A", None) for _, blob in repo.index.iter_blobs()}
+        )
         return changed_files
 
     for merge_base in repo.merge_base(
@@ -262,9 +309,9 @@ def get_changed_files(
         )
         for diff in diffs:
             if diff.change_type == "A":
-                changed_files[diff.b_path] = None
+                changed_files[diff.b_path] = (diff.change_type, None)
             elif diff.change_type != "D":
-                changed_files[diff.b_path] = diff.a_blob
+                changed_files[diff.b_path] = (diff.change_type, diff.a_blob)
 
     return changed_files
 
@@ -313,16 +360,17 @@ def the_check(linter: Linter, args: argparse.Namespace):
             return
 
         try:
-            changed_file = changed_files[git_filename]
+            change_type, changed_file = changed_files[git_filename]
         except KeyError:
             return
 
-        old_content = (
-            changed_file.data_stream.read().decode()
-            if changed_file is not None
-            else None
-        )
-        apply_copyright_check(linter, old_content)
+        if changed_file is None:
+            old_filename = None
+            old_content = None
+        else:
+            old_filename = changed_file.path
+            old_content = changed_file.data_stream.read().decode()
+        apply_copyright_check(linter, change_type, old_filename, old_content)
 
     return the_check
 

src/rapids_pre_commit_hooks/lint.py

@@ -19,25 +19,13 @@
 import functools
 import re
 import warnings
-from collections.abc import Callable, Generator, Iterable
+from collections.abc import Callable
+from itertools import pairwise
 from typing import Optional
 
 from rich.console import Console
 from rich.markup import escape
 
-
-# Taken from Python docs
-# (https://docs.python.org/3.12/library/itertools.html#itertools.pairwise)
-# Replace with itertools.pairwise after dropping Python 3.9 support
-def _pairwise(iterable: Iterable) -> Generator:
-    # pairwise('ABCDEFG') → AB BC CD DE EF FG
-    iterator = iter(iterable)
-    a = next(iterator, None)
-    for b in iterator:
-        yield a, b
-        a = b
-
-
 _PosType = tuple[int, int]
 
 
@@ -66,9 +54,9 @@ class LintWarning:
     pos: _PosType
     msg: str
     replacements: list[Replacement] = dataclasses.field(
-        default_factory=list, init=False
+        default_factory=list, kw_only=True
     )
-    notes: list[Note] = dataclasses.field(default_factory=list, init=False)
+    notes: list[Note] = dataclasses.field(default_factory=list, kw_only=True)
 
     def add_replacement(self, pos: _PosType, newtext: str) -> None:
         self.replacements.append(Replacement(pos, newtext))
@@ -102,7 +90,7 @@ def fix(self) -> str:
             key=lambda replacement: replacement.pos,
         )
 
-        for r1, r2 in _pairwise(sorted_replacements):
+        for r1, r2 in pairwise(sorted_replacements):
             if r1.pos[1] > r2.pos[0]:
                 raise OverlappingReplacementsError(f"{r1} overlaps with {r2}")