Start on test_compat

And rename test_attributes to test_toplevel accordingly.

Author: EliahKagan

test/deprecation/test_compat.py

@@ -0,0 +1,33 @@
+"""Tests for dynamic and static errors and warnings in GitPython's git.compat module.
+
+These tests verify that the is_<platform> aliases are available, and are even listed in
+the output of dir(), but issue warnings, and that bogus (misspelled or unrecognized)
+attribute access is still an error both at runtime and with mypy. This is similar to
+some of the tests in test_toplevel, but the situation being tested here is simpler
+because it does not involve unintuitive module aliasing or import behavior. So this only
+tests attribute access, not "from" imports (whose behavior can be intuitively inferred).
+"""
+
+import os
+import sys
+
+import pytest
+
+import git.compat
+
+
+_MESSAGE_LEADER = "{} and other is_<platform> aliases are deprecated."
+
+
+def test_cannot_access_undefined() -> None:
+    """Accessing a bogus attribute in git.compat remains a dynamic and static error."""
+    with pytest.raises(AttributeError):
+        git.compat.foo  # type: ignore[attr-defined]
+
+
+def test_is_win() -> None:
+    with pytest.deprecated_call() as ctx:
+        value = git.compat.is_win
+    (message,) = [str(entry.message) for entry in ctx]  # Exactly one message.
+    assert message.startswith(_MESSAGE_LEADER.format("git.compat.is_win"))
+    assert value == (os.name == "nt")

test/deprecation/test_attributes.py renamed to test/deprecation/test_toplevel.py

@@ -1,4 +1,4 @@
-"""Tests for dynamic and static attribute errors in GitPython's top-level git module.
+"""Tests for dynamic and static errors and warnings in GitPython's top-level git module.
 
 Provided mypy has ``warn_unused_ignores = true`` set, running mypy on these test cases
 checks static typing of the code under test. This is the reason for the many separate
@@ -31,13 +31,13 @@
 
 
 def test_cannot_access_undefined() -> None:
-    """Accessing a bogus attribute in git remains both a dynamic and static error."""
+    """Accessing a bogus attribute in git remains a dynamic and static error."""
     with pytest.raises(AttributeError):
         git.foo  # type: ignore[attr-defined]
 
 
 def test_cannot_import_undefined() -> None:
-    """Importing a bogus attribute from git remains both a dynamic and static error."""
+    """Importing a bogus attribute from git remains a dynamic and static error."""
     with pytest.raises(ImportError):
         from git import foo  # type: ignore[attr-defined]  # noqa: F401