Make setuptools-rust play nice with cffi

.travis.yml

@@ -26,4 +26,11 @@ script:
   - cd html-py-ever
   - pip install -r requirements-dev.txt
   - python setup.py install
-  - if [[ $TRAVIS_PYTHON_VERSION == 3.6 ]]; then cd test && pytest; fi
+  - if [[ $TRAVIS_PYTHON_VERSION == 3.6 ]]; then cd test && pytest && cd ..; fi
+  - cd ..
+  - cd examples/
+  # PEP517 build isolation means we don't use the setuptools-rust locally,
+  # instead it installs from PyPI!
+  - pip install -U pip
+  - pip install --no-use-pep517 -e rust_with_cffi/
+  - pytest rust_with_cffi/tests.py

examples/rust_with_cffi/Cargo.toml

@@ -0,0 +1,12 @@
+[package]
+name = "rust_with_cffi"
+version = "0.1.0"
+authors = ["Alex Gaynor <[email protected]>"]
+edition = "2018"
+
+[dependencies]
+pyo3 = { version = "0.11.1", features = ["extension-module"]}
+
+[lib]
+name = "rust_with_cffi"
+crate-type = ["cdylib"]

examples/rust_with_cffi/cffi_module.py

@@ -0,0 +1,12 @@
+import cffi
+
+
+ffi = cffi.FFI()
+ffi.cdef("""
+int cffi_func(void);
+""")
+ffi.set_source("rust_with_cffi.cffi", """
+int cffi_func(void) {
+	return 15;
+}
+""")

examples/rust_with_cffi/pyproject.toml

@@ -0,0 +1,2 @@
+[build-system]
+requires = ["setuptools", "wheel", "setuptools-rust", "cffi"]

examples/rust_with_cffi/setup.py

@@ -0,0 +1,30 @@
+#!/usr/bin/env python
+import sys
+
+from setuptools import setup
+
+from setuptools_rust import RustExtension
+
+setup_requires = ["setuptools-rust>=0.10.1", "wheel", "cffi"]
+install_requires = ["cffi"]
+
+setup(
+    name="rust-with-cffi",
+    version="0.1.0",
+    classifiers=[
+        "License :: OSI Approved :: MIT License",
+        "Development Status :: 3 - Alpha",
+        "Intended Audience :: Developers",
+        "Programming Language :: Python",
+        "Programming Language :: Rust",
+        "Operating System :: POSIX",
+        "Operating System :: MacOS :: MacOS X",
+    ],
+    packages=["rust_with_cffi"],
+    rust_extensions=[RustExtension("rust_with_cffi.rust")],
+    cffi_modules=["cffi_module.py:ffi"],
+    install_requires=install_requires,
+    setup_requires=setup_requires,
+    include_package_data=True,
+    zip_safe=False,
+)

examples/rust_with_cffi/src/lib.rs

@@ -0,0 +1,14 @@
+use pyo3::prelude::*;
+use pyo3::wrap_pyfunction;
+
+#[pyfunction]
+fn rust_func() -> PyResult<u64> {
+	return Ok(14);
+}
+
+#[pymodule]
+fn rust(_py: Python<'_>, m: &PyModule) -> PyResult<()> {
+    m.add_wrapped(wrap_pyfunction!(rust_func))?;
+
+    Ok(())
+}

examples/rust_with_cffi/tests.py

@@ -0,0 +1,10 @@
+from rust_with_cffi import rust
+from rust_with_cffi.cffi import lib
+
+
+def test_rust():
+	assert rust.rust_func() == 14
+
+
+def test_cffi():
+	assert lib.cffi_func() == 15