DEVX-134: feat: add I/O function isolation check and skip integration tests

tests/unit/test_check_test_isolation.py

@@ -566,6 +566,147 @@ class TestKnownHelpers:
         assert "subprocess" in HELPER_INTERNAL_CALLS["update_doc_versions"]
 
 
+class TestIOFunctionChecks:
+    """Tests for unpatched I/O function detection."""
+
+    def test_unpatched_get_pat_violation(self, tmp_path: Path) -> None:
+        file = _write_test_file(
+            tmp_path,
+            """
+            from mymodule import get_pat
+
+            class TestExample:
+                def test_calls_get_pat(self) -> None:
+                    result = get_pat("staging")
+        """,
+        )
+        violations = analyze_file(file)
+        assert len(violations) == 1
+        assert violations[0].category == "unpatched-io"
+        assert "get_pat" in violations[0].message
+
+    def test_patched_get_pat_no_violation(self, tmp_path: Path) -> None:
+        file = _write_test_file(
+            tmp_path,
+            """
+            from unittest.mock import patch
+            from mymodule import get_pat
+
+            class TestExample:
+                @patch("mymodule.get_pat", return_value="pat")
+                def test_patched(self, mock) -> None:
+                    result = get_pat("staging")
+        """,
+        )
+        violations = analyze_file(file)
+        assert violations == []
+
+    def test_unpatched_load_secrets_violation(self, tmp_path: Path) -> None:
+        file = _write_test_file(
+            tmp_path,
+            """
+            from mymodule import load_secrets
+
+            class TestExample:
+                def test_calls_load_secrets(self) -> None:
+                    result = load_secrets("staging")
+        """,
+        )
+        violations = analyze_file(file)
+        assert len(violations) == 1
+        assert violations[0].category == "unpatched-io"
+        assert "load_secrets" in violations[0].message
+
+    def test_patched_load_secrets_no_violation(self, tmp_path: Path) -> None:
+        file = _write_test_file(
+            tmp_path,
+            """
+            from unittest.mock import patch
+            from mymodule import load_secrets
+
+            class TestExample:
+                @patch("mymodule.load_secrets", return_value={})
+                def test_patched(self, mock) -> None:
+                    result = load_secrets("staging")
+        """,
+        )
+        violations = analyze_file(file)
+        assert violations == []
+
+    def test_unpatched_requests_get_violation(self, tmp_path: Path) -> None:
+        file = _write_test_file(
+            tmp_path,
+            """
+            import requests
+
+            class TestExample:
+                def test_calls_requests(self) -> None:
+                    resp = requests.get("https://example.com")
+        """,
+        )
+        violations = analyze_file(file)
+        assert len(violations) == 1
+        assert violations[0].category == "unpatched-io"
+        assert "requests.get" in violations[0].message or "get" in violations[0].message
+
+    def test_integration_marker_skips_subprocess(self, tmp_path: Path) -> None:
+        """@pytest.mark.integration tests should not be flagged for subprocess.run."""
+        file = _write_test_file(
+            tmp_path,
+            """
+            import subprocess
+            import pytest
+
+            @pytest.mark.integration
+            def test_real_subprocess():
+                subprocess.run(["echo", "hello"])
+        """,
+        )
+        violations = analyze_file(file)
+        assert violations == []
+
+    def test_integration_marker_skips_sleep(self, tmp_path: Path) -> None:
+        """@pytest.mark.integration tests should not be flagged for time.sleep."""
+        file = _write_test_file(
+            tmp_path,
+            """
+            import time
+            import pytest
+
+            @pytest.mark.integration
+            def test_real_sleep():
+                time.sleep(1)
+        """,
+        )
+        violations = analyze_file(file)
+        assert violations == []
+
+    def test_integration_marker_with_args_skips(self, tmp_path: Path) -> None:
+        """@pytest.mark.integration(...) with args should also be skipped."""
+        file = _write_test_file(
+            tmp_path,
+            """
+            import subprocess
+            import pytest
+
+            @pytest.mark.integration(scope="module")
+            def test_real_subprocess():
+                subprocess.run(["echo", "hello"])
+        """,
+        )
+        violations = analyze_file(file)
+        assert violations == []
+
+    def test_integration_directory_skipped(self, tmp_path: Path) -> None:
+        """Files in integration/ directories should be skipped entirely."""
+        integration_dir = tmp_path / "integration"
+        integration_dir.mkdir()
+        file = integration_dir / "test_real_io.py"
+        file.write_text("import subprocess\ndef test_real_subprocess():\n    subprocess.run(['echo', 'hello'])\n")
+        violations = analyze_file(file)
+        assert violations == []
+
+
 class TestCli:
     """Tests for the standalone CLI interface."""