refactor: consider order in hash methods and make _markers attribute …

…a tuple instead of a list because it must not be changed

src/poetry/core/constraints/generic/multi_constraint.py

@@ -128,11 +128,7 @@ def __eq__(self, other: object) -> bool:
         return self._constraints == other._constraints
 
     def __hash__(self) -> int:
-        h = hash("multi")
-        for constraint in self._constraints:
-            h ^= hash(constraint)
-
-        return h
+        return hash(("multi", *self._constraints))
 
     def __str__(self) -> str:
         constraints = [str(constraint) for constraint in self._constraints]

src/poetry/core/constraints/generic/union_constraint.py

@@ -178,11 +178,7 @@ def __eq__(self, other: object) -> bool:
         return self._constraints == other._constraints
 
     def __hash__(self) -> int:
-        h = hash("union")
-        for constraint in self._constraints:
-            h ^= hash(constraint)
-
-        return h
+        return hash(("union", *self._constraints))
 
     def __str__(self) -> str:
         constraints = [str(constraint) for constraint in self._constraints]

src/poetry/core/version/markers.py

@@ -152,7 +152,7 @@ def __repr__(self) -> str:
         return "<AnyMarker>"
 
     def __hash__(self) -> int:
-        return hash(("<any>", "<any>"))
+        return hash("any")
 
     def __eq__(self, other: object) -> bool:
         if not isinstance(other, BaseMarker):
@@ -193,7 +193,7 @@ def __repr__(self) -> str:
         return "<EmptyMarker>"
 
     def __hash__(self) -> int:
-        return hash(("<empty>", "<empty>"))
+        return hash("empty")
 
     def __eq__(self, other: object) -> bool:
         if not isinstance(other, BaseMarker):
@@ -232,6 +232,10 @@ def name(self) -> str:
     def constraint(self) -> SingleMarkerConstraint:
         return self._constraint
 
+    @property
+    def _key(self) -> tuple[object, ...]:
+        return self._name, self._constraint
+
     def validate(self, environment: dict[str, Any] | None) -> bool:
         if environment is None:
             return True
@@ -284,10 +288,10 @@ def __eq__(self, other: object) -> bool:
         if not isinstance(other, SingleMarkerLike):
             return NotImplemented
 
-        return self._name == other.name and self._constraint == other.constraint
+        return self._key == other._key
 
     def __hash__(self) -> int:
-        return hash((self._name, self._constraint))
+        return hash(self._key)
 
 
 class SingleMarker(SingleMarkerLike[Union[BaseConstraint, VersionConstraint]]):
@@ -368,6 +372,10 @@ def operator(self) -> str:
     def value(self) -> str:
         return self._value
 
+    @property
+    def _key(self) -> tuple[object, ...]:
+        return self._name, self._operator, self._value
+
     def invert(self) -> BaseMarker:
         if self._operator in ("===", "=="):
             operator = "!="
@@ -417,10 +425,10 @@ def __eq__(self, other: object) -> bool:
         if not isinstance(other, SingleMarker):
             return NotImplemented
 
-        return str(self) == str(other)
+        return self._key == other._key
 
     def __hash__(self) -> int:
-        return hash(str(self))
+        return hash(self._key)
 
     def __str__(self) -> str:
         return f'{self._name} {self._operator} "{self._value}"'
@@ -503,10 +511,10 @@ def _flatten_markers(
 
 class MultiMarker(BaseMarker):
     def __init__(self, *markers: BaseMarker) -> None:
-        self._markers = _flatten_markers(markers, MultiMarker)
+        self._markers = tuple(_flatten_markers(markers, MultiMarker))
 
     @property
-    def markers(self) -> list[BaseMarker]:
+    def markers(self) -> tuple[BaseMarker, ...]:
         return self._markers
 
     @property
@@ -657,11 +665,7 @@ def __eq__(self, other: object) -> bool:
         return self._markers == other.markers
 
     def __hash__(self) -> int:
-        h = hash("multi")
-        for m in self._markers:
-            h ^= hash(m)
-
-        return h
+        return hash(("multi", *self._markers))
 
     def __str__(self) -> str:
         elements = []
@@ -676,10 +680,10 @@ def __str__(self) -> str:
 
 class MarkerUnion(BaseMarker):
     def __init__(self, *markers: BaseMarker) -> None:
-        self._markers = _flatten_markers(markers, MarkerUnion)
+        self._markers = tuple(_flatten_markers(markers, MarkerUnion))
 
     @property
-    def markers(self) -> list[BaseMarker]:
+    def markers(self) -> tuple[BaseMarker, ...]:
         return self._markers
 
     @property
@@ -744,12 +748,6 @@ def of(cls, *markers: BaseMarker) -> BaseMarker:
 
         return MarkerUnion(*new_markers)
 
-    def append(self, marker: BaseMarker) -> None:
-        if marker in self._markers:
-            return
-
-        self._markers.append(marker)
-
     def intersect(self, other: BaseMarker) -> BaseMarker:
         return intersection(self, other)
 
@@ -837,11 +835,7 @@ def __eq__(self, other: object) -> bool:
         return self._markers == other.markers
 
     def __hash__(self) -> int:
-        h = hash("union")
-        for m in self._markers:
-            h ^= hash(m)
-
-        return h
+        return hash(("union", *self._markers))
 
     def __str__(self) -> str:
         return " or ".join(str(m) for m in self._markers)

tests/version/test_markers.py

@@ -376,10 +376,10 @@ def test_multi_marker() -> None:
     m = parse_marker('sys_platform == "darwin" and implementation_name == "cpython"')
 
     assert isinstance(m, MultiMarker)
-    assert m.markers == [
+    assert m.markers == (
         parse_marker('sys_platform == "darwin"'),
         parse_marker('implementation_name == "cpython"'),
-    ]
+    )
 
 
 def test_multi_marker_is_empty_is_contradictory() -> None:
@@ -652,10 +652,10 @@ def test_marker_union() -> None:
     m = parse_marker('sys_platform == "darwin" or implementation_name == "cpython"')
 
     assert isinstance(m, MarkerUnion)
-    assert m.markers == [
+    assert m.markers == (
         parse_marker('sys_platform == "darwin"'),
         parse_marker('implementation_name == "cpython"'),
-    ]
+    )
 
 
 def test_marker_union_deduplicate() -> None: