tests: run on pyodide (#4745)

* tests: run on pyodide

Signed-off-by: Henry Schreiner <henryschreineriii@gmail.com>

* ci: use cibuildwheel for pyodide test

Signed-off-by: Henry Schreiner <henryschreineriii@gmail.com>

* tests: revert changes to test_embed

Signed-off-by: Henry Schreiner <henryschreineriii@gmail.com>

---------

Signed-off-by: Henry Schreiner <henryschreineriii@gmail.com>

.github/workflows/emscripten.yaml

+name: WASM
+
+on:
+  workflow_dispatch:
+  pull_request:
+    branches:
+    - master
+
+concurrency:
+  group: ${{ github.workflow }}-${{ github.ref }}
+  cancel-in-progress: true
+
+jobs:
+  build-wasm-emscripten:
+    name: Pyodide wheel
+    runs-on: ubuntu-22.04
+    steps:
+    - uses: actions/checkout@v4
+      with:
+        submodules: true
+        fetch-depth: 0
+
+    - uses: pypa/cibuildwheel@v2.19
+      env:
+        PYODIDE_BUILD_EXPORTS: whole_archive
+        CFLAGS: -fexceptions
+        LDFLAGS: -fexceptions
+      with:
+        package-dir: tests
+        only: cp312-pyodide_wasm32

tests/CMakeLists.txt

@@ -88,7 +88,12 @@ set(PYBIND11_TEST_FILTER
 if(CMAKE_CURRENT_SOURCE_DIR STREQUAL CMAKE_SOURCE_DIR)
   # We're being loaded directly, i.e. not via add_subdirectory, so make this
   # work as its own project and load the pybind11Config to get the tools we need
+
+  if(SKBUILD)
+    add_subdirectory(.. pybind11_src)
+  else()
     find_package(pybind11 REQUIRED CONFIG)
+  endif()
 endif()
 
 if(NOT CMAKE_BUILD_TYPE AND NOT DEFINED CMAKE_CONFIGURATION_TYPES)
@@ -489,6 +494,9 @@ foreach(target ${test_targets})
       endforeach()
     endif()
   endif()
+  if(SKBUILD)
+    install(TARGETS ${target} LIBRARY DESTINATION .)
+  endif()
 endforeach()
 
 # Provide nice organisation in IDEs

tests/pyproject.toml

+# Warning: this is currently used for pyodide, and is not a general out-of-tree
+# builder for the tests (yet). Specifically, wheels can't be built from SDists.
+
+[build-system]
+requires = ["scikit-build-core"]
+build-backend = "scikit_build_core.build"
+
+[project]
+name = "pybind11_tests"
+version = "0.0.1"
+dependencies = ["pytest", "pytest-timeout", "numpy", "scipy"]
+
+[tool.scikit-build.cmake.define]
+PYBIND11_FINDPYTHON = true
+
+[tool.cibuildwheel]
+test-command = "pytest -o timeout=0 -p no:cacheprovider {project}/tests/test_*.py"

tests/test_async.py

 from __future__ import annotations
 
+import sys
+
 import pytest
 
 asyncio = pytest.importorskip("asyncio")
 m = pytest.importorskip("pybind11_tests.async_module")
 
+if sys.platform.startswith("emscripten"):
+    pytest.skip("Can't run a new event_loop in pyodide", allow_module_level=True)
+
 
 @pytest.fixture()
 def event_loop():

tests/test_callbacks.py

 from __future__ import annotations
 
+import sys
 import time
 from threading import Thread
 
@@ -153,6 +154,7 @@ def test_python_builtins():
     assert m.test_sum_builtin(sum, []) == 0
 
 
+@pytest.mark.skipif(sys.platform.startswith("emscripten"), reason="Requires threads")
 def test_async_callbacks():
     # serves as state for async callback
     class Item:
@@ -176,6 +178,7 @@ def test_async_callbacks():
     assert sum(res) == sum(x + 3 for x in work)
 
 
+@pytest.mark.skipif(sys.platform.startswith("emscripten"), reason="Requires threads")
 def test_async_async_callbacks():
     t = Thread(target=test_async_callbacks)
     t.start()

tests/test_exceptions.py

@@ -75,7 +75,7 @@ def test_cross_module_exceptions(msg):
 
 # TODO: FIXME
 @pytest.mark.xfail(
-    "env.MACOS and (env.PYPY or pybind11_tests.compiler_info.startswith('Homebrew Clang'))",
+    "env.MACOS and (env.PYPY or pybind11_tests.compiler_info.startswith('Homebrew Clang')) or sys.platform.startswith('emscripten')",
     raises=RuntimeError,
     reason="See Issue #2847, PR #2999, PR #4324",
 )

tests/test_gil_scoped.py

@@ -71,24 +71,28 @@ def test_cross_module_gil_inner_pybind11_acquired():
     m.test_cross_module_gil_inner_pybind11_acquired()
 
 
+@pytest.mark.skipif(sys.platform.startswith("emscripten"), reason="Requires threads")
 def test_cross_module_gil_nested_custom_released():
     """Makes sure that the GIL can be nested acquired/released by another module
     from a GIL-released state using custom locking logic."""
     m.test_cross_module_gil_nested_custom_released()
 
 
+@pytest.mark.skipif(sys.platform.startswith("emscripten"), reason="Requires threads")
 def test_cross_module_gil_nested_custom_acquired():
     """Makes sure that the GIL can be nested acquired/acquired by another module
     from a GIL-acquired state using custom locking logic."""
     m.test_cross_module_gil_nested_custom_acquired()
 
 
+@pytest.mark.skipif(sys.platform.startswith("emscripten"), reason="Requires threads")
 def test_cross_module_gil_nested_pybind11_released():
     """Makes sure that the GIL can be nested acquired/released by another module
     from a GIL-released state using pybind11 locking logic."""
     m.test_cross_module_gil_nested_pybind11_released()
 
 
+@pytest.mark.skipif(sys.platform.startswith("emscripten"), reason="Requires threads")
 def test_cross_module_gil_nested_pybind11_acquired():
     """Makes sure that the GIL can be nested acquired/acquired by another module
     from a GIL-acquired state using pybind11 locking logic."""
@@ -103,6 +107,7 @@ def test_nested_acquire():
     assert m.test_nested_acquire(0xAB) == "171"
 
 
+@pytest.mark.skipif(sys.platform.startswith("emscripten"), reason="Requires threads")
 def test_multi_acquire_release_cross_module():
     for bits in range(16 * 8):
         internals_ids = m.test_multi_acquire_release_cross_module(bits)
@@ -204,7 +209,7 @@ def _run_in_threads(test_fn, num_threads, parallel):
         thread.join()
 
 
-# TODO: FIXME, sometimes returns -11 (segfault) instead of 0 on macOS Python 3.9
+@pytest.mark.skipif(sys.platform.startswith("emscripten"), reason="Requires threads")
 @pytest.mark.parametrize("test_fn", ALL_BASIC_TESTS_PLUS_INTENTIONAL_DEADLOCK)
 def test_run_in_process_one_thread(test_fn):
     """Makes sure there is no GIL deadlock when running in a thread.
@@ -214,7 +219,7 @@ def test_run_in_process_one_thread(test_fn):
     assert _run_in_process(_run_in_threads, test_fn, num_threads=1, parallel=False) == 0
 
 
-# TODO: FIXME on macOS Python 3.9
+@pytest.mark.skipif(sys.platform.startswith("emscripten"), reason="Requires threads")
 @pytest.mark.parametrize("test_fn", ALL_BASIC_TESTS_PLUS_INTENTIONAL_DEADLOCK)
 def test_run_in_process_multiple_threads_parallel(test_fn):
     """Makes sure there is no GIL deadlock when running in a thread multiple times in parallel.
@@ -224,7 +229,7 @@ def test_run_in_process_multiple_threads_parallel(test_fn):
     assert _run_in_process(_run_in_threads, test_fn, num_threads=8, parallel=True) == 0
 
 
-# TODO: FIXME on macOS Python 3.9
+@pytest.mark.skipif(sys.platform.startswith("emscripten"), reason="Requires threads")
 @pytest.mark.parametrize("test_fn", ALL_BASIC_TESTS_PLUS_INTENTIONAL_DEADLOCK)
 def test_run_in_process_multiple_threads_sequential(test_fn):
     """Makes sure there is no GIL deadlock when running in a thread multiple times sequentially.
@@ -234,7 +239,7 @@ def test_run_in_process_multiple_threads_sequential(test_fn):
     assert _run_in_process(_run_in_threads, test_fn, num_threads=8, parallel=False) == 0
 
 
-# TODO: FIXME on macOS Python 3.9
+@pytest.mark.skipif(sys.platform.startswith("emscripten"), reason="Requires threads")
 @pytest.mark.parametrize("test_fn", ALL_BASIC_TESTS_PLUS_INTENTIONAL_DEADLOCK)
 def test_run_in_process_direct(test_fn):
     """Makes sure there is no GIL deadlock when using processes.

tests/test_iostream.py

 from __future__ import annotations
 
+import sys
 from contextlib import redirect_stderr, redirect_stdout
 from io import StringIO
 
+import pytest
+
 from pybind11_tests import iostream as m
 
 
@@ -270,6 +273,7 @@ def test_redirect_both(capfd):
     assert stream2.getvalue() == msg2
 
 
+@pytest.mark.skipif(sys.platform.startswith("emscripten"), reason="Requires threads")
 def test_threading():
     with m.ostream_redirect(stdout=True, stderr=False):
         # start some threads

tests/test_thread.py

 from __future__ import annotations
 
+import sys
 import threading
 
+import pytest
+
 from pybind11_tests import thread as m
 
 
@@ -24,6 +27,7 @@ class Thread(threading.Thread):
             raise self.e
 
 
+@pytest.mark.skipif(sys.platform.startswith("emscripten"), reason="Requires threads")
 def test_implicit_conversion():
     a = Thread(m.test)
     b = Thread(m.test)
@@ -34,6 +38,7 @@ def test_implicit_conversion():
         x.join()
 
 
+@pytest.mark.skipif(sys.platform.startswith("emscripten"), reason="Requires threads")
 def test_implicit_conversion_no_gil():
     a = Thread(m.test_no_gil)
     b = Thread(m.test_no_gil)

tests/test_virtual_functions.py

 from __future__ import annotations
 
+import sys
+
 import pytest
 
 import env  # noqa: F401
@@ -435,6 +437,7 @@ def test_inherited_virtuals():
     assert obj.say_everything() == "BT -7"
 
 
+@pytest.mark.skipif(sys.platform.startswith("emscripten"), reason="Requires threads")
 def test_issue_1454():
     # Fix issue #1454 (crash when acquiring/releasing GIL on another thread in Python 2.7)
     m.test_gil()