Exclude dev depenencies

synapse/util/check_dependencies.py

@@ -53,7 +53,16 @@ def dependencies(self) -> Iterable[str]:
             yield '"' + i + '"'
 
 
-EXTRAS = set(metadata.metadata(DISTRIBUTION_NAME).get_all("Provides-Extra"))
+DEV_EXTRAS = {"lint", "mypy", "test", "dev"}
+RUNTIME_EXTRAS = (
+    set(metadata.metadata(DISTRIBUTION_NAME).get_all("Provides-Extra")) - DEV_EXTRAS
+)
+
+
+def _is_dev_dependency(req: Requirement) -> bool:
+    return req.marker is not None and any(
+        req.marker.evaluate({"extra": e}) for e in DEV_EXTRAS
+    )
 
 
 class Dependency(NamedTuple):
@@ -67,6 +76,9 @@ def _generic_dependencies() -> Iterable[Dependency]:
     assert requirements is not None
     for raw_requirement in requirements:
         req = Requirement(raw_requirement)
+        if _is_dev_dependency(req):
+            continue
+
         # https://packaging.pypa.io/en/latest/markers.html#usage notes that
         #   > Evaluating an extra marker with no environment is an error
         # so we pass in a dummy empty extra value here.
@@ -80,6 +92,8 @@ def _dependencies_for_extra(extra: str) -> Iterable[Dependency]:
     assert requirements is not None
     for raw_requirement in requirements:
         req = Requirement(raw_requirement)
+        if _is_dev_dependency(req):
+            continue
         # Exclude mandatory deps by only selecting deps needed with this extra.
         if (
             req.marker is not None
@@ -124,7 +138,7 @@ def check_requirements(extra: Optional[str] = None) -> None:
     # First work out which dependencies are required, and which are optional.
     if extra is None:
         dependencies = _generic_dependencies()
-    elif extra in EXTRAS:
+    elif extra in RUNTIME_EXTRAS:
         dependencies = _dependencies_for_extra(extra)
     else:
         raise ValueError(f"Synapse does not provide the feature '{extra}'")

tests/util/test_check_dependencies.py

@@ -65,6 +65,23 @@ def test_mandatory_dependency(self) -> None:
                 # should not raise
                 check_requirements()
 
+    def test_checks_ignore_dev_dependencies(self) -> None:
+        """Bot generic and per-extra checks should ignore dev dependencies."""
+        with patch(
+            "synapse.util.check_dependencies.metadata.requires",
+            return_value=["dummypkg >= 1; extra == 'mypy'"],
+        ), patch("synapse.util.check_dependencies.RUNTIME_EXTRAS", {"cool-extra"}):
+            # We're testing that none of these calls raise.
+            with self.mock_installed_package(None):
+                check_requirements()
+                check_requirements("cool-extra")
+            with self.mock_installed_package(old):
+                check_requirements()
+                check_requirements("cool-extra")
+            with self.mock_installed_package(new):
+                check_requirements()
+                check_requirements("cool-extra")
+
     def test_generic_check_of_optional_dependency(self) -> None:
         """Complain if an optional package is old."""
         with patch(
@@ -85,7 +102,7 @@ def test_check_for_extra_dependencies(self) -> None:
         with patch(
             "synapse.util.check_dependencies.metadata.requires",
             return_value=["dummypkg >= 1; extra == 'cool-extra'"],
-        ), patch("synapse.util.check_dependencies.EXTRAS", {"cool-extra"}):
+        ), patch("synapse.util.check_dependencies.RUNTIME_EXTRAS", {"cool-extra"}):
             with self.mock_installed_package(None):
                 self.assertRaises(DependencyException, check_requirements, "cool-extra")
             with self.mock_installed_package(old):