move alias module to own file

Author: RonnyPfannschmidt

src/apipkg/__init__.py

@@ -16,6 +16,7 @@
 from typing import cast
 from typing import Iterable
 
+from ._alias_module import AliasModule
 from ._importing import _py_abspath
 from ._importing import distribution_version as distribution_version  # NOQA:F401
 from ._importing import importobj
@@ -225,38 +226,3 @@ def __dict__(self) -> dict[str, Any]:  # type: ignore
                 except AttributeError:
                     pass
         return ns
-
-
-def AliasModule(modname: str, modpath: str, attrname: str | None = None) -> ModuleType:
-    cached_obj: object | None = None
-
-    def getmod() -> object:
-        nonlocal cached_obj
-        if cached_obj is None:
-            cached_obj = importobj(modpath, attrname)
-        return cached_obj
-
-    x = modpath + ("." + attrname if attrname else "")
-    repr_result = f"<AliasModule {modname!r} for {x!r}>"
-
-    class AliasModule(ModuleType):
-        def __repr__(self) -> str:
-            return repr_result
-
-        def __getattribute__(self, name: str) -> object:
-            try:
-                return getattr(getmod(), name)
-            except ImportError:
-                if modpath == "pytest" and attrname is None:
-                    # hack for pylibs py.test
-                    return None
-                else:
-                    raise
-
-        def __setattr__(self, name: str, value: object) -> None:
-            setattr(getmod(), name, value)
-
-        def __delattr__(self, name: str) -> None:
-            delattr(getmod(), name)
-
-    return AliasModule(str(modname))

src/apipkg/_alias_module

@@ -0,0 +1,41 @@
+from __future__ import annotations
+
+from types import ModuleType
+
+from ._importing import importobj
+
+
+def AliasModule(modname: str, modpath: str, attrname: str | None = None) -> ModuleType:
+
+    cached_obj: object | None = None
+
+    def getmod() -> object:
+        nonlocal cached_obj
+        if cached_obj is None:
+            cached_obj = importobj(modpath, attrname)
+        return cached_obj
+
+    x = modpath + ("." + attrname if attrname else "")
+    repr_result = f"<AliasModule {modname!r} for {x!r}>"
+
+    class AliasModule(ModuleType):
+        def __repr__(self) -> str:
+            return repr_result
+
+        def __getattribute__(self, name: str) -> object:
+            try:
+                return getattr(getmod(), name)
+            except ImportError:
+                if modpath == "pytest" and attrname is None:
+                    # hack for pylibs py.test
+                    return None
+                else:
+                    raise
+
+        def __setattr__(self, name: str, value: object) -> None:
+            setattr(getmod(), name, value)
+
+        def __delattr__(self, name: str) -> None:
+            delattr(getmod(), name)
+
+    return AliasModule(str(modname))

src/apipkg/_alias_module.py

@@ -7,12 +7,12 @@
 
 import pytest
 
-import apipkg
-
+import apipkg._alias_module
 
 #
 # test support for importing modules
 #
+
 ModuleType = types.ModuleType
 
 
@@ -705,15 +705,15 @@ def test_extra_attributes(tmpdir, monkeypatch):
 
 
 def test_aliasmodule_aliases_an_attribute():
-    am = apipkg.AliasModule("mymod", "pprint", "PrettyPrinter")
+    am = apipkg._alias_module.AliasModule("mymod", "pprint", "PrettyPrinter")
     r = repr(am)
     assert "<AliasModule 'mymod' for 'pprint.PrettyPrinter'>" == r
     assert am.format
     assert not hasattr(am, "lqkje")
 
 
 def test_aliasmodule_aliases_unimportable_fails():
-    am = apipkg.AliasModule("mymod", "qlwkejqlwe", "main")
+    am = apipkg._alias_module.AliasModule("mymod", "qlwkejqlwe", "main")
     r = repr(am)
     assert "<AliasModule 'mymod' for 'qlwkejqlwe.main'>" == r
     # this would pass starting with apipkg 1.3 to work around a pytest bug
@@ -725,21 +725,21 @@ def test_aliasmodule_pytest_autoreturn_none_for_hack(monkeypatch):
     def error(*k):
         raise ImportError(k)
 
-    monkeypatch.setattr(apipkg, "importobj", error)
+    monkeypatch.setattr(apipkg._alias_module, "importobj", error)
     # apipkg 1.3 added this hack
-    am = apipkg.AliasModule("mymod", "pytest")
+    am = apipkg._alias_module.AliasModule("mymod", "pytest")
     r = repr(am)
     assert "<AliasModule 'mymod' for 'pytest'>" == r
     assert am.test is None
 
 
 def test_aliasmodule_unicode():
-    am = apipkg.AliasModule("mymod", "pprint")
+    am = apipkg._alias_module.AliasModule("mymod", "pprint")
     assert am
 
 
 def test_aliasmodule_repr():
-    am = apipkg.AliasModule("mymod", "sys")
+    am = apipkg._alias_module.AliasModule("mymod", "sys")
     r = repr(am)
     assert "<AliasModule 'mymod' for 'sys'>" == r
     am.version
@@ -861,7 +861,9 @@ def test_importlib_find_spec_fake_module(find_spec):
 
 
 def test_importlib_find_spec_aliasmodule(find_spec):
-    am = apipkg.AliasModule("apipkg.testmodule.example.email_spec", "email")
+    am = apipkg._alias_module.AliasModule(
+        "apipkg.testmodule.example.email_spec", "email"
+    )
     spec = find_spec(am.__name__)
     assert spec is am.__spec__