Add mypyc infrastructure tests and tooling config

- Add 22 tests covering detection, activation, import hook, sentinel
- Add mypyc tox environment
- Add *.so to .gitignore
- Add ruff exceptions for build_mypyc.py

Author: claude

.gitignore

@@ -27,3 +27,4 @@ __pycache__/
 *.lock
 *.log
 *.py[cod]
+*.so

pyproject.toml

@@ -149,6 +149,13 @@ ignore = [
 "*/__init__.py" = [
    "I001",  # imports do not need to be sorted
 ]
+"build_mypyc.py" = [
+   "BLE001",  # allow catching blind exception
+   "EXE001",  # shebang for documentation
+   "I001",  # imports in logical order
+   "PTH",  # simpler path handling for script
+   "T201",  # print is expected in CLI script
+]
 "src/graphql/execution/*" = [
     "BLE001",  # allow catching blind exception
 ]

tests/mypyc/__init__.py

@@ -0,0 +1 @@
+"""Tests for mypyc compilation infrastructure."""

tests/mypyc/test_mypyc_infrastructure.py

@@ -0,0 +1,259 @@
+"""Tests for mypyc compilation infrastructure."""
+
+from __future__ import annotations
+
+
+def describe_mypyc_detection():
+    """Tests for mypyc detection utilities."""
+
+    def exports_detection_functions():
+        """The graphql module exports mypyc detection functions."""
+        import graphql
+
+        assert hasattr(graphql, "is_mypyc_enabled")
+        assert hasattr(graphql, "get_mypyc_modules")
+        assert callable(graphql.is_mypyc_enabled)
+        assert callable(graphql.get_mypyc_modules)
+
+    def is_mypyc_enabled_returns_bool():
+        """is_mypyc_enabled returns a boolean."""
+        import graphql
+
+        result = graphql.is_mypyc_enabled()
+        assert isinstance(result, bool)
+
+    def get_mypyc_modules_returns_frozenset():
+        """get_mypyc_modules returns a frozenset of strings."""
+        import graphql
+
+        result = graphql.get_mypyc_modules()
+        assert isinstance(result, frozenset)
+
+
+def describe_mypyc_module():
+    """Tests for the graphql_mypyc module."""
+
+    def can_import_graphql_mypyc():
+        """The graphql_mypyc module can be imported."""
+        import graphql_mypyc
+
+        assert graphql_mypyc is not None
+
+    def exports_activate_deactivate():
+        """The graphql_mypyc module exports activate/deactivate functions."""
+        import graphql_mypyc
+
+        assert hasattr(graphql_mypyc, "activate")
+        assert hasattr(graphql_mypyc, "deactivate")
+        assert hasattr(graphql_mypyc, "is_active")
+        assert callable(graphql_mypyc.activate)
+        assert callable(graphql_mypyc.deactivate)
+        assert callable(graphql_mypyc.is_active)
+
+    def exports_compiled_modules_set():
+        """The graphql_mypyc module exports COMPILED_MODULES."""
+        import graphql_mypyc
+
+        assert hasattr(graphql_mypyc, "COMPILED_MODULES")
+        assert isinstance(graphql_mypyc.COMPILED_MODULES, frozenset)
+
+    def exports_version():
+        """The graphql_mypyc module exports __version__."""
+        import graphql_mypyc
+
+        assert hasattr(graphql_mypyc, "__version__")
+        assert isinstance(graphql_mypyc.__version__, str)
+
+
+def describe_mypyc_activation():
+    """Tests for mypyc activation/deactivation."""
+
+    def activation_is_idempotent():
+        """Calling activate multiple times is safe."""
+        import graphql_mypyc
+
+        # Should already be active from auto-activation
+        result1 = graphql_mypyc.activate()
+        result2 = graphql_mypyc.activate()
+        assert result1 is True
+        assert result2 is True
+
+    def deactivation_works():
+        """Deactivation disables mypyc mode."""
+        import graphql
+        import graphql_mypyc
+
+        # Deactivate
+        graphql_mypyc.deactivate()
+        assert graphql_mypyc.is_active() is False
+        assert graphql.is_mypyc_enabled() is False
+
+        # Reactivate for other tests
+        graphql_mypyc.activate()
+        assert graphql_mypyc.is_active() is True
+        assert graphql.is_mypyc_enabled() is True
+
+    def deactivation_is_idempotent():
+        """Calling deactivate multiple times is safe."""
+        import graphql_mypyc
+
+        # Deactivate twice
+        graphql_mypyc.deactivate()
+        result1 = graphql_mypyc.deactivate()
+        result2 = graphql_mypyc.deactivate()
+        assert result1 is True
+        assert result2 is True
+
+        # Reactivate for other tests
+        graphql_mypyc.activate()
+
+
+def describe_mypyc_auto_activation():
+    """Tests for automatic mypyc activation on import."""
+
+    def auto_activates_when_graphql_mypyc_available():
+        """Auto-activates mypyc when graphql_mypyc is installed."""
+        # Since graphql_mypyc is in our src/, it's always available
+        # and should be auto-activated when graphql is imported
+        import graphql
+
+        # The module should report as enabled (hook is installed)
+        # Note: This tests the hook infrastructure, not actual compilation
+        assert graphql.is_mypyc_enabled() is True
+
+    def compiled_modules_reflects_current_state():
+        """get_mypyc_modules returns the currently compiled modules."""
+        import graphql
+        import graphql_mypyc
+
+        # The compiled modules set should match what's registered
+        modules = graphql.get_mypyc_modules()
+        assert modules == graphql_mypyc.COMPILED_MODULES
+
+
+def describe_import_hook():
+    """Tests for the import hook mechanism."""
+
+    def hook_module_exports():
+        """The _hook module exports expected functions."""
+        from graphql_mypyc._hook import (
+            COMPILED_MODULES,
+            install_hook,
+            is_hook_installed,
+            uninstall_hook,
+        )
+
+        assert isinstance(COMPILED_MODULES, frozenset)
+        assert callable(install_hook)
+        assert callable(uninstall_hook)
+        assert callable(is_hook_installed)
+
+    def hook_is_installed_after_activation():
+        """The import hook is installed after activation."""
+        import graphql_mypyc
+        from graphql_mypyc._hook import is_hook_installed
+
+        graphql_mypyc.activate()
+        assert is_hook_installed() is True
+
+    def hook_is_removed_after_deactivation():
+        """The import hook is removed after deactivation."""
+        import graphql_mypyc
+        from graphql_mypyc._hook import is_hook_installed
+
+        graphql_mypyc.deactivate()
+        assert is_hook_installed() is False
+
+        # Reactivate for other tests
+        graphql_mypyc.activate()
+
+    def compiled_modules_contains_sentinel():
+        """COMPILED_MODULES includes the sentinel module."""
+        from graphql_mypyc._hook import COMPILED_MODULES
+
+        assert "graphql._sentinel" in COMPILED_MODULES
+
+
+def describe_sentinel_module():
+    """Tests for the sentinel module that validates the import hook."""
+
+    def graphql_sentinel_exists():
+        """The graphql._sentinel module can be imported."""
+        from graphql import _sentinel
+
+        assert _sentinel is not None
+
+    def graphql_mypyc_sentinel_exists():
+        """The graphql_mypyc._sentinel module can be imported."""
+        from graphql_mypyc import _sentinel
+
+        assert _sentinel is not None
+
+    def sentinel_has_expected_exports():
+        """The sentinel module exports expected functions."""
+        from graphql import _sentinel
+
+        assert hasattr(_sentinel, "is_compiled")
+        assert hasattr(_sentinel, "add_numbers")
+        assert hasattr(_sentinel, "SENTINEL_VALUE")
+        assert callable(_sentinel.is_compiled)
+        assert callable(_sentinel.add_numbers)
+
+    def sentinel_add_numbers_works():
+        """The sentinel add_numbers function works correctly."""
+        from graphql import _sentinel
+
+        assert _sentinel.add_numbers(2, 3) == 5
+        assert _sentinel.add_numbers(-1, 1) == 0
+
+    def hook_redirects_to_mypyc_version():
+        """With hook active, graphql._sentinel gets graphql_mypyc._sentinel."""
+        import sys
+
+        import graphql_mypyc
+
+        # Ensure hook is active
+        graphql_mypyc.activate()
+
+        # Remove any cached import of graphql._sentinel
+        if "graphql._sentinel" in sys.modules:
+            del sys.modules["graphql._sentinel"]
+
+        # Import with hook active - should get redirected
+        from graphql import _sentinel
+
+        # The SENTINEL_VALUE tells us which version we got
+        # graphql_mypyc._sentinel has "mypyc-compiled"
+        # graphql._sentinel (fallback) has "interpreted"
+        assert _sentinel.SENTINEL_VALUE == "mypyc-compiled"
+
+    def without_hook_gets_interpreted_version():
+        """With hook inactive, graphql._sentinel is the interpreted version."""
+        import sys
+
+        import graphql
+        import graphql_mypyc
+
+        # Deactivate hook
+        graphql_mypyc.deactivate()
+
+        # Remove any cached import from sys.modules
+        if "graphql._sentinel" in sys.modules:
+            del sys.modules["graphql._sentinel"]
+
+        # Also remove the cached attribute from the graphql module
+        # (Python caches submodule imports as attributes on the parent)
+        if hasattr(graphql, "_sentinel"):
+            delattr(graphql, "_sentinel")
+
+        # Import without hook - should get original
+        from graphql import _sentinel
+
+        assert _sentinel.SENTINEL_VALUE == "interpreted"
+
+        # Reactivate for other tests and clear cache
+        graphql_mypyc.activate()
+        if "graphql._sentinel" in sys.modules:
+            del sys.modules["graphql._sentinel"]
+        if hasattr(graphql, "_sentinel"):
+            delattr(graphql, "_sentinel")

tox.ini

@@ -1,5 +1,5 @@
 [tox]
-envlist = py3{10,11,12,13,14}, pypy3{10,11}, ruff, mypy, docs
+envlist = py3{10,11,12,13,14}, pypy3{10,11}, ruff, mypy, mypyc, docs
 isolated_build = true
 requires =
     tox>=4.34
@@ -33,6 +33,19 @@ skip_install = true
 commands =
     python -m mypy src tests
 
+[testenv:mypyc]
+# Test the mypyc compilation infrastructure
+# This verifies the import hook, detection, and activation work correctly
+basepython = python3.14
+dependency_groups = test
+commands =
+    # Run mypyc infrastructure tests
+    python -m pytest tests/mypyc -v {posargs}
+    # Verify mypyc detection is working
+    python -c "import graphql; assert graphql.is_mypyc_enabled(), 'mypyc should be enabled'"
+    python -c "import graphql; print(f'mypyc enabled: {{graphql.is_mypyc_enabled()}}')"
+    python -c "import graphql; print(f'compiled modules: {{graphql.get_mypyc_modules()}}')"
+
 [testenv:docs]
 basepython = python3.14
 dependency_groups = doc