constraints: add full support for unions of generic constraints

python-poetry · Nov 28, 2022 · 4c4f817 · 4c4f817
1 parent 375f793
commit 4c4f817
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Showing 4 changed files with 185 additions and 7 deletions.
diff --git a/src/poetry/core/constraints/generic/empty_constraint.py b/src/poetry/core/constraints/generic/empty_constraint.py
@@ -24,6 +24,9 @@ def allows_any(self, other: BaseConstraint) -> bool:
     def intersect(self, other: BaseConstraint) -> BaseConstraint:
         return self
 
+    def union(self, other: BaseConstraint) -> BaseConstraint:
+        return other
+
     def difference(self, other: BaseConstraint) -> BaseConstraint:
         return self
 

diff --git a/src/poetry/core/constraints/generic/multi_constraint.py b/src/poetry/core/constraints/generic/multi_constraint.py
@@ -1,5 +1,6 @@
 from __future__ import annotations
 
+from poetry.core.constraints.generic import AnyConstraint
 from poetry.core.constraints.generic import EmptyConstraint
 from poetry.core.constraints.generic.base_constraint import BaseConstraint
 from poetry.core.constraints.generic.constraint import Constraint
@@ -77,6 +78,26 @@ def intersect(self, other: BaseConstraint) -> BaseConstraint:
 
         return MultiConstraint(*self._constraints, other)
 
+    def union(self, other: BaseConstraint) -> BaseConstraint:
+        if not isinstance(other, Constraint):
+            return other.union(self)
+
+        if other in self._constraints:
+            return other
+
+        if other.value not in (c.value for c in self._constraints):
+            if other.operator == "!=":
+                return AnyConstraint()
+
+            return self
+
+        constraints = [c for c in self._constraints if c.value != other.value]
+
+        if len(constraints) == 1:
+            return constraints[0]
+
+        return MultiConstraint(*constraints)
+
     def __eq__(self, other: object) -> bool:
         if not isinstance(other, MultiConstraint):
             return False

diff --git a/src/poetry/core/constraints/generic/union_constraint.py b/src/poetry/core/constraints/generic/union_constraint.py
@@ -1,5 +1,6 @@
 from __future__ import annotations
 
+from poetry.core.constraints.generic import AnyConstraint
 from poetry.core.constraints.generic.base_constraint import BaseConstraint
 from poetry.core.constraints.generic.constraint import Constraint
 from poetry.core.constraints.generic.empty_constraint import EmptyConstraint
@@ -108,15 +109,45 @@ def intersect(self, other: BaseConstraint) -> BaseConstraint:
 
         return UnionConstraint(*new_constraints)
 
-    def union(self, other: BaseConstraint) -> UnionConstraint:
-        if not isinstance(other, Constraint):
-            raise ValueError("Unimplemented constraint union")
+    def union(self, other: BaseConstraint) -> BaseConstraint:
+        if other.is_any():
+            return other
+
+        if other.is_empty():
+            return self
+
+        if isinstance(other, Constraint):
+            # (A or B) or C => A or B or C
+            # just a special case of UnionConstraint
+            other = UnionConstraint(other)
+
+        new_constraints: list[BaseConstraint] = []
+        if isinstance(other, UnionConstraint):
+            # (A or B) or (C or D) => A or B or C or D
+            for our_constraint in self._constraints:
+                for their_constraint in other.constraints:
+                    union = our_constraint.union(their_constraint)
+                    if union.is_any():
+                        return AnyConstraint()
+                    if isinstance(union, Constraint):
+                        if union not in new_constraints:
+                            new_constraints.append(union)
+                    else:
+                        if our_constraint not in new_constraints:
+                            new_constraints.append(our_constraint)
+                        if their_constraint not in new_constraints:
+                            new_constraints.append(their_constraint)
+
+        else:
+            assert isinstance(other, MultiConstraint)
+            # (A or B) or (C and D) => nothing to do
 
-        constraints = self._constraints
-        if other not in self._constraints:
-            constraints += (other,)
+            new_constraints = [*self._constraints, other]
 
-        return UnionConstraint(*constraints)
+        if len(new_constraints) == 1:
+            return new_constraints[0]
+
+        return UnionConstraint(*new_constraints)
 
     def __eq__(self, other: object) -> bool:
         if not isinstance(other, UnionConstraint):

diff --git a/tests/constraints/generic/test_constraint.py b/tests/constraints/generic/test_constraint.py
@@ -217,6 +217,51 @@ def test_intersect(
 @pytest.mark.parametrize(
     ("constraint1", "constraint2", "expected"),
     [
+        (
+            EmptyConstraint(),
+            Constraint("win32"),
+            Constraint("win32"),
+        ),
+        (
+            EmptyConstraint(),
+            MultiConstraint(Constraint("darwin", "!="), Constraint("linux", "!=")),
+            MultiConstraint(Constraint("darwin", "!="), Constraint("linux", "!=")),
+        ),
+        (
+            EmptyConstraint(),
+            UnionConstraint(Constraint("win32"), Constraint("linux")),
+            UnionConstraint(Constraint("win32"), Constraint("linux")),
+        ),
+        (
+            AnyConstraint(),
+            Constraint("win32"),
+            AnyConstraint(),
+        ),
+        (
+            AnyConstraint(),
+            MultiConstraint(Constraint("darwin", "!="), Constraint("linux", "!=")),
+            AnyConstraint(),
+        ),
+        (
+            AnyConstraint(),
+            UnionConstraint(Constraint("win32"), Constraint("linux")),
+            AnyConstraint(),
+        ),
+        (
+            EmptyConstraint(),
+            AnyConstraint(),
+            AnyConstraint(),
+        ),
+        (
+            EmptyConstraint(),
+            EmptyConstraint(),
+            EmptyConstraint(),
+        ),
+        (
+            AnyConstraint(),
+            AnyConstraint(),
+            AnyConstraint(),
+        ),
         (
             Constraint("win32"),
             Constraint("win32"),
@@ -227,6 +272,25 @@ def test_intersect(
             Constraint("linux"),
             UnionConstraint(Constraint("win32"), Constraint("linux")),
         ),
+        (
+            Constraint("win32"),
+            MultiConstraint(Constraint("darwin", "!="), Constraint("linux", "!=")),
+            MultiConstraint(Constraint("darwin", "!="), Constraint("linux", "!=")),
+        ),
+        (
+            Constraint("win32"),
+            MultiConstraint(Constraint("win32", "!="), Constraint("linux", "!=")),
+            Constraint("linux", "!="),
+        ),
+        (
+            Constraint("win32"),
+            MultiConstraint(
+                Constraint("win32", "!="),
+                Constraint("linux", "!="),
+                Constraint("darwin", "!="),
+            ),
+            MultiConstraint(Constraint("linux", "!="), Constraint("darwin", "!=")),
+        ),
         (
             Constraint("win32"),
             UnionConstraint(Constraint("win32"), Constraint("linux")),
@@ -254,6 +318,65 @@ def test_intersect(
             Constraint("linux", "!="),
             AnyConstraint(),
         ),
+        (
+            Constraint("win32", "!="),
+            MultiConstraint(Constraint("win32", "!="), Constraint("linux", "!=")),
+            Constraint("win32", "!="),
+        ),
+        (
+            Constraint("darwin", "!="),
+            MultiConstraint(Constraint("win32", "!="), Constraint("linux", "!=")),
+            AnyConstraint(),
+        ),
+        (
+            Constraint("win32", "!="),
+            UnionConstraint(Constraint("win32"), Constraint("linux")),
+            AnyConstraint(),
+        ),
+        (
+            Constraint("win32", "!="),
+            UnionConstraint(Constraint("linux"), Constraint("linux2")),
+            Constraint("win32", "!="),
+        ),
+        (
+            UnionConstraint(Constraint("win32"), Constraint("linux")),
+            UnionConstraint(Constraint("win32"), Constraint("darwin")),
+            UnionConstraint(
+                Constraint("win32"), Constraint("linux"), Constraint("darwin")
+            ),
+        ),
+        (
+            UnionConstraint(
+                Constraint("win32"), Constraint("linux"), Constraint("darwin")
+            ),
+            UnionConstraint(
+                Constraint("win32"), Constraint("cygwin"), Constraint("darwin")
+            ),
+            UnionConstraint(
+                Constraint("win32"),
+                Constraint("linux"),
+                Constraint("darwin"),
+                Constraint("cygwin"),
+            ),
+        ),
+        (
+            UnionConstraint(Constraint("win32"), Constraint("linux")),
+            MultiConstraint(Constraint("win32", "!="), Constraint("darwin", "!=")),
+            UnionConstraint(
+                Constraint("win32"),
+                Constraint("linux"),
+                MultiConstraint(Constraint("win32", "!="), Constraint("darwin", "!=")),
+            ),
+        ),
+        (
+            UnionConstraint(Constraint("win32"), Constraint("linux")),
+            MultiConstraint(Constraint("win32", "!="), Constraint("linux", "!=")),
+            UnionConstraint(
+                Constraint("win32"),
+                Constraint("linux"),
+                MultiConstraint(Constraint("win32", "!="), Constraint("linux", "!=")),
+            ),
+        ),
     ],
 )
 def test_union(