pylock: support package.marker

Author: sbidoul

src/pip/_internal/models/pylock.py

@@ -17,6 +17,7 @@
 )
 
 from pip._vendor import tomli_w
+from pip._vendor.packaging.markers import InvalidMarker, Marker
 from pip._vendor.packaging.version import InvalidVersion, Version
 from pip._vendor.typing_extensions import Self
 
@@ -48,7 +49,7 @@ def _toml_key(key: str) -> str:
 
 
 def _toml_value(value: T) -> Union[str, T]:
-    if isinstance(value, Version):
+    if isinstance(value, (Version, Marker)):
         return str(value)
     return value
 
@@ -98,6 +99,16 @@ def _get_required_version(d: Dict[str, Any], key: str) -> Version:
     return value
 
 
+def _get_marker(d: Dict[str, Any], key: str) -> Optional[Marker]:
+    value = _get(d, str, key)
+    if value is None:
+        return None
+    try:
+        return Marker(value)
+    except InvalidMarker:
+        raise PylockValidationError(f"invalid marker {value!r}")
+
+
 def _get_object(
     d: Dict[str, Any], expected_type: Type[PylockDataClassT], key: str
 ) -> Optional[PylockDataClassT]:
@@ -274,7 +285,7 @@ def from_dict(cls, d: Dict[str, Any]) -> Self:
 class Package:
     name: str
     version: Optional[Version] = None
-    # (not supported) marker: Optional[str]
+    marker: Optional[Marker] = None
     # (not supported) requires_python: Optional[str]
     # (not supported) dependencies
     vcs: Optional[PackageVcs] = None
@@ -296,6 +307,7 @@ def from_dict(cls, d: Dict[str, Any]) -> Self:
         package = cls(
             name=_get_required(d, str, "name"),
             version=_get_version(d, "version"),
+            marker=_get_marker(d, "marker"),
             vcs=_get_object(d, PackageVcs, "vcs"),
             directory=_get_object(d, PackageDirectory, "directory"),
             archive=_get_object(d, PackageArchive, "archive"),
@@ -381,6 +393,7 @@ def from_install_requirement(cls, ireq: InstallRequirement, base_dir: Path) -> S
         return cls(
             name=dist.canonical_name,
             version=package_version,
+            marker=None,
             vcs=package_vcs,
             directory=package_directory,
             archive=package_archive,

tests/unit/test_pylock.py

@@ -1,5 +1,8 @@
 import pytest
 
+from pip._vendor.packaging.markers import Marker
+from pip._vendor.packaging.version import Version
+
 from pip._internal.models.pylock import (
     Pylock,
     PylockRequiredKeyError,
@@ -80,3 +83,26 @@ def test_pylock_packages_without_dist() -> None:
         str(exc_info.value)
         == "Exactly one of vcs, directory, archive, sdist, wheels must be set"
     )
+
+
+def test_pylock_basic_package() -> None:
+    data = {
+        "lock-version": "1.0",
+        "created-by": "pip",
+        "packages": [
+            {
+                "name": "example",
+                "version": "1.0",
+                "marker": 'os_name == "posix"',
+                "directory": {
+                    "path": ".",
+                    "editable": False,
+                },
+            }
+        ],
+    }
+    pylock = Pylock.from_dict(data)
+    package = pylock.packages[0]
+    assert package.version == Version("1.0")
+    assert package.marker == Marker('os_name == "posix"')
+    assert pylock.to_dict() == data