FilterList: Add boilerplate for mypy

Author: jorio

pygit2/_libgit2/ffi.pyi

@@ -123,6 +123,10 @@ class GitBlameC:
     # incomplete
     pass
 
+class GitBlobC:
+    # incomplete
+    pass
+
 class GitMergeOptionsC:
     file_favor: int
     flags: int
@@ -177,6 +181,10 @@ class GitDescribeOptionsC:
 class GitDescribeResultC:
     pass
 
+class GitFilterListC:
+    # opaque struct
+    pass
+
 class GitIndexC:
     pass
 
@@ -264,6 +272,8 @@ def new(a: Literal['git_oid *']) -> GitOidC: ...
 @overload
 def new(a: Literal['git_blame **']) -> _Pointer[GitBlameC]: ...
 @overload
+def new(a: Literal['git_blob **']) -> _Pointer[GitBlobC]: ...
+@overload
 def new(a: Literal['git_clone_options *']) -> GitCloneOptionsC: ...
 @overload
 def new(a: Literal['git_merge_options *']) -> GitMergeOptionsC: ...
@@ -318,6 +328,8 @@ def new(a: Literal['git_signature *']) -> GitSignatureC: ...
 @overload
 def new(a: Literal['git_signature **']) -> _Pointer[GitSignatureC]: ...
 @overload
+def new(a: Literal['git_filter_list **']) -> _Pointer[GitFilterListC]: ...
+@overload
 def new(a: Literal['int *']) -> int_c: ...
 @overload
 def new(a: Literal['int64_t *']) -> int64_t: ...

pygit2/filter.py

@@ -23,14 +23,21 @@
 # the Free Software Foundation, 51 Franklin Street, Fifth Floor,
 # Boston, MA 02110-1301, USA.
 
+from __future__ import annotations
+
 import weakref
 from collections.abc import Callable
+from typing import TYPE_CHECKING
 
-from ._pygit2 import Blob, FilterSource, Repository
+from ._pygit2 import Blob, FilterSource
 from .errors import check_error
 from .ffi import C, ffi
+from .repository import BaseRepository
 from .utils import to_bytes
 
+if TYPE_CHECKING:
+    from ._libgit2.ffi import GitFilterListC
+
 
 class Filter:
     """
@@ -114,7 +121,9 @@ def close(self, write_next: Callable[[bytes], None]) -> None:
 
 
 class FilterList:
-    _all_filter_lists = set()
+    _all_filter_lists: set[weakref.ReferenceType[FilterList]] = set()
+
+    _pointer: GitFilterListC
 
     @classmethod
     def _from_c(cls, ptr):
@@ -134,7 +143,14 @@ def _from_c(cls, ptr):
 
     @classmethod
     def _is_filter_in_use(cls, name: str) -> bool:
-        return any(name in ref() for ref in cls._all_filter_lists)
+        for ref in cls._all_filter_lists:
+            fl = ref()
+            assert fl is not None, (
+                'dead FilterList refs should be purged by weakref callback'
+            )
+            if name in fl:
+                return True
+        return False
 
     def __contains__(self, name: str) -> bool:
         if not isinstance(name, str):
@@ -159,7 +175,7 @@ def apply_to_buffer(self, data: bytes) -> bytes:
         finally:
             C.git_buf_dispose(buf)
 
-    def apply_to_file(self, repo: Repository, path: str) -> bytes:
+    def apply_to_file(self, repo: BaseRepository, path: str) -> bytes:
         """
         Apply a filter list to the contents of a file on disk.
         Return the filtered contents.

test/test_filter.py

@@ -152,19 +152,22 @@ def test_filterlist_crlf(testrepo: Repository) -> None:
     assert 'crlf' in fl
 
     with pytest.raises(TypeError):
-        1234 in fl
+        # Incorrect on purpose to raise TypeError
+        1234 in fl  # type: ignore
 
 
 def test_filterlist_crlf_clean(testrepo: Repository) -> None:
     testrepo.config['core.autocrlf'] = True
     fl = testrepo.load_filter_list('whatever.txt', mode=FilterMode.CLEAN)
+    assert fl is not None
     filtered = fl.apply_to_buffer(b'hello\r\nworld\r\n')
     assert filtered == b'hello\nworld\n'
 
 
 def test_filterlist_crlf_smudge(testrepo: Repository) -> None:
     testrepo.config['core.autocrlf'] = True
     fl = testrepo.load_filter_list('whatever.txt', mode=FilterMode.SMUDGE)
+    assert fl is not None
     filtered = fl.apply_to_buffer(b'hello\nworld\n')
     assert filtered == b'hello\r\nworld\r\n'
 
@@ -197,6 +200,7 @@ def test_filterlist_rot13_apply_to_buffer(
     testrepo: Repository, rot13_filter: Filter
 ) -> None:
     fl = testrepo.load_filter_list('whatever.txt')
+    assert fl is not None
     filtered = fl.apply_to_buffer(b'bye world\n')
     assert filtered == b'olr jbeyq\n'
 
@@ -205,6 +209,7 @@ def test_filterlist_rot13_apply_to_file(
     testrepo: Repository, rot13_filter: Filter
 ) -> None:
     fl = testrepo.load_filter_list('bye.txt')
+    assert fl is not None
     filtered = fl.apply_to_file(testrepo, 'bye.txt')
     assert filtered == b'olr jbeyq\n'
 
@@ -213,7 +218,9 @@ def test_filterlist_rot13_apply_to_blob(
     testrepo: Repository, rot13_filter: Filter
 ) -> None:
     fl = testrepo.load_filter_list('whatever.txt')
+    assert fl is not None
     blob_oid = testrepo.create_blob(b'bye world\n')
     blob = testrepo[blob_oid]
+    assert isinstance(blob, Blob)
     filtered = fl.apply_to_blob(blob)
     assert filtered == b'olr jbeyq\n'