fix: check for mutually exclusive markers

src/poetry/factory.py

@@ -4,6 +4,7 @@
 import logging
 import re
 
+from itertools import combinations
 from typing import TYPE_CHECKING
 from typing import Any
 from typing import cast
@@ -358,7 +359,15 @@ def validate(
 
         results["errors"].extend(validate_object(config))
 
-        # A project should not depend on itself.
+        cls._validate_project_should_not_depend_on_itself(config, results)
+        cls._validate_dependencies_have_mutually_exclusive_markers(config, results)
+
+        return results
+
+    @staticmethod
+    def _validate_project_should_not_depend_on_itself(
+        config: dict[str, Any], results: dict[str, list[str]]
+    ) -> None:
         dependencies = set(config.get("dependencies", {}).keys())
         dependencies.update(config.get("dev-dependencies", {}).keys())
         groups = config.get("group", {}).values()
@@ -369,7 +378,33 @@ def validate(
 
         if canonicalize_name(config["name"]) in dependencies:
             results["errors"].append(
-                f"Project name ({config['name']}) is same as one of its dependencies"
+                f"Project name ({config['name']}) is same as one of its dependencies."
             )
 
-        return results
+    @classmethod
+    def _validate_dependencies_have_mutually_exclusive_markers(
+        cls, config: dict[str, Any], results: dict[str, list[str]]
+    ) -> None:
+        dep_groups = [
+            config.get("dependencies", {}),
+            config.get("dev-dependencies", {}),
+            *(
+                group.get("dependencies", {})
+                for group in config.get("group", {}).values()
+            ),
+        ]
+        for group in dep_groups:
+            for name, constraints in group.items():
+                if isinstance(constraints, list) and len(constraints) > 1:
+                    deps = [
+                        cls.create_dependency(name, constraint)
+                        for constraint in constraints
+                    ]
+                    if not all(
+                        d1.marker.intersect(d2.marker).is_empty()
+                        for d1, d2 in combinations(deps, 2)
+                    ):
+                        results["errors"].append(
+                            f"Dependency {name} does not have mutually exclusive"
+                            " markers."
+                        )

tests/console/commands/test_check.py

@@ -43,7 +43,8 @@ def test_check_invalid(
 
     expected = """\
 Error: 'description' is a required property
-Error: Project name (invalid) is same as one of its dependencies
+Error: Project name (invalid) is same as one of its dependencies.
+Error: Dependency pillow does not have mutually exclusive markers.
 Error: Unrecognized classifiers: ['Intended Audience :: Clowns'].
 Warning: A wildcard Python dependency is ambiguous.\
  Consider specifying a more explicit one.

tests/fixtures/invalid_pyproject/pyproject.toml

@@ -1,18 +1,20 @@
 [tool.poetry]
-name = "invalid"
-version = "1.0.0"
-authors = [
-    "Foo <[email protected]>"
-]
-license = "INVALID"
+authors = ["Foo <[email protected]>"]
 classifiers = [
     "Environment :: Console",
     "Intended Audience :: Clowns",
     "Natural Language :: Ukranian",
     "Topic :: Communications :: Chat :: AOL Instant Messenger",
 ]
+license = "INVALID"
+name = "invalid"
+version = "1.0.0"
 
 [tool.poetry.dependencies]
-python = "*"
-pendulum = {"version" = "^2.0.5", allows-prereleases = true}
 invalid = "1.0"
+pendulum = { "version" = "^2.0.5", allows-prereleases = true }
+pillow = [
+    { version = "^9", python = "^3.9" },
+    { version = "^7", python = "^3.7" },
+]
+python = "*"

tests/test_factory.py

@@ -518,7 +518,8 @@ def test_create_poetry_fails_on_invalid_configuration(
     expected = """\
 The Poetry configuration is invalid:
   - 'description' is a required property
-  - Project name (invalid) is same as one of its dependencies
+  - Project name (invalid) is same as one of its dependencies.
+  - Dependency pillow does not have mutually exclusive markers.
 """
     assert str(e.value) == expected