Address code quality

Author: simonkurtz-MSFT

.github/copilot-instructions.md

@@ -46,6 +46,7 @@ In case of any conflicting instructions, the following hierarchy shall apply. If
 - Consider non-native English speakers in code comments and documentation, using clear and simple language.
 - Treat accessibility as a default quality requirement across the entire repository, not only for presentations.
 - New or updated user-facing experiences (docs, webpages, notebooks, dashboards/workbooks, and slide content) must target WCAG 2.0 AA contrast and non-color-only communication as the baseline.
+- Continuously refine repository instructions, skills, and agents when a surfaced problem reveals an addressable gap. Update the narrowest authoritative customization in the same change when practical, so future work benefits without duplicating or overfitting guidance.
 
 ## Consistency & Uniformity
 

.github/python.instructions.md

@@ -101,6 +101,8 @@ Before completing any Python code changes, verify:
 - Slow tests (> 0.1s runtime) should be identified and fixed, if possible.
 - Add or update pytest unit tests when changing behavior.
 - Prefer focused tests for the code being changed.
+- When testing cleanup after an exception, place `pytest.raises(...)` in an outer `with` block and the resource-owning context manager in a nested inner block. Do not combine them in one comma-separated `with` statement because static analysis may report the cleanup assertions as unreachable.
+- If static analysis still treats assertions after `pytest.raises(...)` as unreachable because the test body contains a literal `raise`, trigger the expected exception through the exercised method or a mock `side_effect` instead. Keep the exception and post-block cleanup assertions unchanged.
 - Avoid tests that require live Azure access; mock Azure CLI interactions and `azure_resources` helpers.
 - Every extracted helper requires focused tests for its public success and failure contracts. Include malformed inputs and resource cleanup where applicable.
 - Place sample-local helper tests in `tests/python/test_<sample>_helpers.py` and target at least 95% meaningful statement and branch coverage for changed helper modules.

tests/python/test_auth_testing.py

@@ -109,8 +109,9 @@ def test_structured_expectation_rejects_non_json_response(requests_mock, tests_m
 
 @pytest.mark.unit
 def test_context_manager_closes_requests_on_exception(requests_mock, tests_mock):
-    with pytest.raises(RuntimeError), RoleBasedAuthTestRunner(requests_mock, tests_mock, 'jwt-key'):
-        raise RuntimeError('test failure')
+    with pytest.raises(RuntimeError):
+        with RoleBasedAuthTestRunner(requests_mock, tests_mock, 'jwt-key'):
+            raise RuntimeError('test failure')
 
     requests_mock.close.assert_called_once_with()
 

tests/python/test_dynamic_cors_helpers.py

@@ -70,11 +70,12 @@ def test_runner_persists_results_when_cell_raises(monkeypatch, tmp_path):
     runner = _create_runner(monkeypatch, results_path)
     suite = MagicMock()
     suite.verify.return_value = False
+    fail_cell = MagicMock(side_effect=RuntimeError('cell failed'))
 
     with pytest.raises(RuntimeError, match='cell failed'):
         with runner:
             runner.track(suite, 'Option 1', 'recorded before failure', 500, 200)
-            raise RuntimeError('cell failed')
+            fail_cell()
 
     assert load_test_results(results_path)[0]['Test'] == 'recorded before failure'
     runner.session.close.assert_called_once()

tests/python/test_secure_blob_access_helpers.py

@@ -142,11 +142,12 @@ def test_runner_preserves_failed_download_body_and_closes_after_exception():
     session.get.return_value.text = 'forbidden details'
     runner = SecureBlobAccessRunner(requests, session_factory=lambda: session)
 
-    with pytest.raises(RuntimeError, match='cell failed'), runner:
-        download = runner.download(ValetKey('https://storage/blob', None))
-        assert download.content is None
-        assert download.response_body == 'forbidden details'
-        raise RuntimeError('cell failed')
+    with pytest.raises(RuntimeError, match='cell failed'):
+        with runner:
+            download = runner.download(ValetKey('https://storage/blob', None))
+            assert download.content is None
+            assert download.response_body == 'forbidden details'
+            raise RuntimeError('cell failed')
 
     session.close.assert_called_once_with()
     requests.close.assert_called_once_with()