Check if requirement is typed in strict_typing IQS validation (#133415)

* Check if requirement is typed in strict_typing IQS validation

* Apply suggestions from code review

* Apply suggestions from code review

* Return a list

* Adjust

* Improve

script/hassfest/quality_scale_validation/strict_typing.py

@@ -4,6 +4,7 @@ https://developers.home-assistant.io/docs/core/integration-quality-scale/rules/s
 """
 
 from functools import lru_cache
+from importlib import metadata
 from pathlib import Path
 import re
 
@@ -24,6 +25,29 @@ def _strict_typing_components(strict_typing_file: Path) -> set[str]:
     )
 
 
+def _check_requirements_are_typed(integration: Integration) -> list[str]:
+    """Check if all requirements are typed."""
+    invalid_requirements = []
+    for requirement in integration.requirements:
+        requirement_name, requirement_version = requirement.split("==")
+        # Remove any extras
+        requirement_name = requirement_name.split("[")[0]
+        try:
+            distribution = metadata.distribution(requirement_name)
+        except metadata.PackageNotFoundError:
+            # Package not installed locally
+            continue
+        if distribution.version != requirement_version:
+            # Version out of date locally
+            continue
+
+        if not any(file for file in distribution.files if file.name == "py.typed"):
+            # no py.typed file
+            invalid_requirements.append(requirement)
+
+    return invalid_requirements
+
+
 def validate(
     config: Config, integration: Integration, *, rules_done: set[str]
 ) -> list[str] | None:
@@ -35,4 +59,9 @@ def validate(
             "Integration does not have strict typing enabled "
             "(is missing from .strict-typing)"
         ]
+    if untyped_requirements := _check_requirements_are_typed(integration):
+        return [
+            f"Requirements {untyped_requirements} do not conform PEP 561 (https://peps.python.org/pep-0561/)",
+            "They should be typed and have a 'py.typed' file",
+        ]
     return None