Convert requirementslib to pydantic (#368)

* Convert requirementslib to pydantic

* Should never import setuptools, causes bad side effects.

* Fix import

* Remove tests of removed functions.

* Fix import

* Fix import

* Fix import

* Fix to use isinstance

* Fix import

* Fix import

* Remove test that tests removed method

* Remove tests of removed  methods.

* fix test

* Remove tests of removed  methods.

* Remove tests of removed  methods.

* Fix python markers.

* Revert "Remove tests of removed  methods."

This reverts commit 73fb203.

* fix tests

* Update test case to avoid antiquated package.

* Check pt tests

* Fix edge case of VCS requirements and expected resulting dictionary.

* Fix more tests

* more test fixes

* down to 6 failing tests

* down to 5 failing tests

* Fix tests, down to 4 failing

* Fix tests, down to 3 failing

* Do not force parse of ireq when it may not be parsable.

* latest changes that work for both pipenv and requirementslib.

* latest changes that work for both pipenv and requirementslib.

* remove test that is problematic in github acttions.

* remove test that is problematic in github acttions.

* Apply fix to failing test.

* PR feedback

* Remove unused type imports

---------

Co-authored-by: Oz Tiram <oz.tiram@gmail.com>

setup.cfg

@@ -41,12 +41,12 @@ classifier =
 zip_safe = true
 python_requires = >=3.7
 install_requires =
-    attrs>=19.2
     distlib>=0.2.8
     pep517>=0.5.0
     pip>=23.1
     platformdirs
     plette[validation]
+    pydantic
     requests
     setuptools>=40.8
     tomlkit>=0.5.3

src/requirementslib/fileutils.py

@@ -91,20 +91,11 @@ def get_long_path(short_path: Text) -> Text:
         return buffer.value
 
 
-def normalize_path(path):
-    """Return a case-normalized absolute variable-expanded path.
-
-    :param str path: The non-normalized path
-    :return: A normalized, expanded, case-normalized path
-    :rtype: str
-    """
-
-    path = os.path.abspath(os.path.expandvars(os.path.expanduser(str(path))))
-    if os.name == "nt" and os.path.exists(path):
-
-        path = get_long_path(path)
-
-    return os.path.normpath(os.path.normcase(path))
+def normalize_path(path: str) -> str:
+    """Return a case-normalized absolute variable-expanded path."""
+    return os.path.expandvars(
+        os.path.expanduser(os.path.normcase(os.path.normpath(os.path.abspath(str(path)))))
+    )
 
 
 def normalize_drive(path):
@@ -114,10 +105,8 @@ def normalize_drive(path):
     identified with either upper or lower cased drive names. The case is
     always converted to uppercase because it seems to be preferred.
     """
-    if os.name != "nt" or not (
-        isinstance(path, str) or getattr(path, "__fspath__", None)
-    ):
-        return path  # type: ignore
+    if os.name != "nt" or not isinstance(path, str):
+        return path
 
     drive, tail = os.path.splitdrive(path)
     # Only match (lower cased) local drives (e.g. 'c:'), not UNC mounts.

src/requirementslib/models/common.py

@@ -0,0 +1,28 @@
+from typing import Any, Dict
+
+from pydantic import BaseModel, Extra
+
+
+class ReqLibBaseModel(BaseModel):
+    def __setattr__(self, name, value):  # noqa: C901 (ignore complexity)
+        private_attributes = {
+            field_name
+            for field_name in self.__annotations__
+            if field_name.startswith("_")
+        }
+
+        if name in private_attributes or name in self.__fields__:
+            return object.__setattr__(self, name, value)
+
+        if self.__config__.extra is not Extra.allow and name not in self.__fields__:
+            raise ValueError(f'"{self.__class__.__name__}" object has no field "{name}"')
+
+        object.__setattr__(self, name, value)
+
+    def dict(self, *args, **kwargs) -> Dict[str, Any]:
+        """The requirementslib classes make use of a lot of private attributes
+        which do not get serialized out to the dict by default in pydantic."""
+        model_dict = super().dict(*args, **kwargs)
+        private_attrs = {k: v for k, v in self.__dict__.items() if k.startswith("_")}
+        model_dict.update(private_attrs)
+        return model_dict