increase mypy strictness (warn unused ignored and warn unreachable)

9 files changed, 28 insertions, 22 deletions

diff --git a/git/cmd.py b/git/cmd.py
index 9d070367..e690dc12 100644
--- a/git/cmd.py
+++ b/git/cmd.py
@@ -42,7 +42,7 @@ from .util import (
 from typing import (Any, AnyStr, BinaryIO, Callable, Dict, IO, Iterator, List, Mapping,
                     Sequence, TYPE_CHECKING, TextIO, Tuple, Union, cast, overload)
 
-from git.types import PathLike, Literal
+from git.types import PathLike, Literal, TBD
 
 if TYPE_CHECKING:
     from git.repo.base import Repo
@@ -575,8 +575,8 @@ class Git(LazyMixin):
         self._environment: Dict[str, str] = {}
 
         # cached command slots
-        self.cat_file_header = None
-        self.cat_file_all = None
+        self.cat_file_header: Union[None, TBD] = None
+        self.cat_file_all: Union[None, TBD] = None
 
     def __getattr__(self, name: str) -> Any:
         """A convenience method as it allows to call the command as if it was
@@ -1012,8 +1012,6 @@ class Git(LazyMixin):
 
     @classmethod
     def __unpack_args(cls, arg_list: Sequence[str]) -> List[str]:
-        if not isinstance(arg_list, (list, tuple)):
-            return [str(arg_list)]
 
         outlist = []
         for arg in arg_list:
diff --git a/git/config.py b/git/config.py
index 91bf65d3..2a5aa142 100644
--- a/git/config.py
+++ b/git/config.py
@@ -236,7 +236,8 @@ def get_config_path(config_level: Lit_config_levels) -> str:
         raise ValueError("No repo to get repository configuration from. Use Repo._get_config_path")
     else:
         # Should not reach here. Will raise ValueError if does. Static typing will warn missing elifs
-        assert_never(config_level, ValueError(f"Invalid configuration level: {config_level!r}"))
+        assert_never(config_level,                    # type: ignore[unreachable]
+                     ValueError(f"Invalid configuration level: {config_level!r}"))
 
 
 class GitConfigParser(cp.RawConfigParser, metaclass=MetaParserBuilder):
diff --git a/git/diff.py b/git/diff.py
index fc16b73e..cea66d7e 100644
--- a/git/diff.py
+++ b/git/diff.py
@@ -456,8 +456,8 @@ class Diff(object):
         # for now, we have to bake the stream
         text = b''.join(text_list)
         index: 'DiffIndex' = DiffIndex()
-        previous_header = None
-        header = None
+        previous_header: Union[Match[bytes], None] = None
+        header: Union[Match[bytes], None] = None
         a_path, b_path = None, None  # for mypy
         a_mode, b_mode = None, None  # for mypy
         for _header in cls.re_header.finditer(text):
diff --git a/git/index/base.py b/git/index/base.py
index 4c8b923a..102703e6 100644
--- a/git/index/base.py
+++ b/git/index/base.py
@@ -1202,7 +1202,6 @@ class IndexFile(LazyMixin, git_diff.Diffable, Serializable):
             handle_stderr(proc, checked_out_files)
             return checked_out_files
         # END paths handling
-        assert "Should not reach this point"
 
     @ default_index
     def reset(self, commit: Union[Commit, 'Reference', str] = 'HEAD', working_tree: bool = False,
diff --git a/git/objects/fun.py b/git/objects/fun.py
index d6cdafe1..19b4e525 100644
--- a/git/objects/fun.py
+++ b/git/objects/fun.py
@@ -51,7 +51,7 @@ def tree_to_stream(entries: Sequence[EntryTup], write: Callable[['ReadableBuffer
         if isinstance(name, str):
             name_bytes = name.encode(defenc)
         else:
-            name_bytes = name
+            name_bytes = name  # type: ignore[unreachable]  # check runtime types - is always str?
         write(b''.join((mode_str, b' ', name_bytes, b'\0', binsha)))
     # END for each item
 
diff --git a/git/objects/tree.py b/git/objects/tree.py
index 0cceb59a..22531895 100644
--- a/git/objects/tree.py
+++ b/git/objects/tree.py
@@ -215,7 +215,7 @@ class Tree(IndexObject, git_diff.Diffable, util.Traversable, util.Serializable):
         super(Tree, self).__init__(repo, binsha, mode, path)
 
     @ classmethod
-    def _get_intermediate_items(cls, index_object: 'Tree',
+    def _get_intermediate_items(cls, index_object: IndexObjUnion,
                                 ) -> Union[Tuple['Tree', ...], Tuple[()]]:
         if index_object.type == "tree":
             return tuple(index_object._iter_convert_to_object(index_object._cache))
diff --git a/git/objects/util.py b/git/objects/util.py
index d3842cfb..9c9ce773 100644
--- a/git/objects/util.py
+++ b/git/objects/util.py
@@ -167,7 +167,7 @@ def from_timestamp(timestamp: float, tz_offset: float) -> datetime:
         return utc_dt
 
 
-def parse_date(string_date: str) -> Tuple[int, int]:
+def parse_date(string_date: Union[str, datetime]) -> Tuple[int, int]:
     """
     Parse the given date as one of the following
 
@@ -182,8 +182,10 @@ def parse_date(string_date: str) -> Tuple[int, int]:
     :note: Date can also be YYYY.MM.DD, MM/DD/YYYY and DD.MM.YYYY.
     """
     if isinstance(string_date, datetime) and string_date.tzinfo:
-        offset = -int(string_date.utcoffset().total_seconds())
+        offset = -int(string_date.utcoffset().total_seconds())  # type: ignore[union-attr]
         return int(string_date.astimezone(utc).timestamp()), offset
+    else:
+        assert isinstance(string_date, str)  # for mypy
 
     # git time
     try:
@@ -338,7 +340,7 @@ class Traversable(Protocol):
         """
         # Commit and Submodule have id.__attribute__ as IterableObj
         # Tree has id.__attribute__ inherited from IndexObject
-        if isinstance(self, (TraversableIterableObj, Has_id_attribute)):
+        if isinstance(self, Has_id_attribute):
             id = self._id_attribute_
         else:
             id = ""     # shouldn't reach here, unless Traversable subclass created with no _id_attribute_
diff --git a/git/repo/base.py b/git/repo/base.py
index 07cf7adf..2609bf55 100644
--- a/git/repo/base.py
+++ b/git/repo/base.py
@@ -200,7 +200,6 @@ class Repo(object):
         # END while curpath
 
         if self.git_dir is None:
-            self.git_dir = cast(PathLike, self.git_dir)
             raise InvalidGitRepositoryError(epath)
 
         self._bare = False
diff --git a/git/repo/fun.py b/git/repo/fun.py
index 7d5c7823..b1b330c4 100644
--- a/git/repo/fun.py
+++ b/git/repo/fun.py
@@ -1,4 +1,6 @@
 """Package with general repository related functions"""
+from git.refs.reference import Reference
+from git.types import Commit_ish
 import os
 import stat
 from string import digits
@@ -202,7 +204,7 @@ def rev_parse(repo: 'Repo', rev: str) -> Union['Commit', 'Tag', 'Tree', 'Blob']:
         raise NotImplementedError("commit by message search ( regex )")
     # END handle search
 
-    obj = cast(Object, None)   # not ideal. Should use guards
+    obj: Union[Commit_ish, Reference, None] = None
     ref = None
     output_type = "commit"
     start = 0
@@ -222,14 +224,16 @@ def rev_parse(repo: 'Repo', rev: str) -> Union['Commit', 'Tag', 'Tree', 'Blob']:
                 ref = repo.head.ref
             else:
                 if token == '@':
-                    ref = name_to_object(repo, rev[:start], return_ref=True)
+                    ref = cast(Reference, name_to_object(repo, rev[:start], return_ref=True))
                 else:
-                    obj = name_to_object(repo, rev[:start])
+                    obj = cast(Commit_ish, name_to_object(repo, rev[:start]))
                 # END handle token
             # END handle refname
+        else:
+            assert obj is not None
 
             if ref is not None:
-                obj = ref.commit
+                obj = cast(Commit, ref.commit)
             # END handle ref
         # END initialize obj on first token
 
@@ -247,11 +251,13 @@ def rev_parse(repo: 'Repo', rev: str) -> Union['Commit', 'Tag', 'Tree', 'Blob']:
                 pass  # default
             elif output_type == 'tree':
                 try:
+                    obj = cast(Object, obj)
                     obj = to_commit(obj).tree
                 except (AttributeError, ValueError):
                     pass    # error raised later
                 # END exception handling
             elif output_type in ('', 'blob'):
+                obj = cast(TagObject, obj)
                 if obj and obj.type == 'tag':
                     obj = deref_tag(obj)
                 else:
@@ -280,13 +286,13 @@ def rev_parse(repo: 'Repo', rev: str) -> Union['Commit', 'Tag', 'Tree', 'Blob']:
                 obj = Object.new_from_sha(repo, hex_to_bin(entry.newhexsha))
 
                 # make it pass the following checks
-                output_type = None
+                output_type = ''
             else:
                 raise ValueError("Invalid output type: %s ( in %s )" % (output_type, rev))
             # END handle output type
 
             # empty output types don't require any specific type, its just about dereferencing tags
-            if output_type and obj.type != output_type:
+            if output_type and obj and obj.type != output_type:
                 raise ValueError("Could not accommodate requested object type %r, got %s" % (output_type, obj.type))
             # END verify output type
 
@@ -319,6 +325,7 @@ def rev_parse(repo: 'Repo', rev: str) -> Union['Commit', 'Tag', 'Tree', 'Blob']:
         parsed_to = start
         # handle hierarchy walk
         try:
+            obj = cast(Commit_ish, obj)
             if token == "~":
                 obj = to_commit(obj)
                 for _ in range(num):
@@ -347,7 +354,7 @@ def rev_parse(repo: 'Repo', rev: str) -> Union['Commit', 'Tag', 'Tree', 'Blob']:
 
     # still no obj ? Its probably a simple name
     if obj is None:
-        obj = name_to_object(repo, rev)
+        obj = cast(Commit_ish, name_to_object(repo, rev))
         parsed_to = lr
     # END handle simple name