Fix cython in scipy-notebook

scipy-notebook/Dockerfile

@@ -8,9 +8,15 @@ LABEL maintainer="Jupyter Project <jupyter@googlegroups.com>"
 
 USER root
 
-# ffmpeg for matplotlib anim & dvipng+cm-super for latex labels
 RUN apt-get update --yes && \
-    apt-get install --yes --no-install-recommends ffmpeg dvipng cm-super && \
+    apt-get install --yes --no-install-recommends \
+    # for cython: https://cython.readthedocs.io/en/latest/src/quickstart/install.html
+    build-essential \
+    # for latex labels
+    cm-super \
+    dvipng \
+    # for matplotlib anim
+    ffmpeg && \
     apt-get clean && rm -rf /var/lib/apt/lists/*
 
 USER ${NB_UID}

tests/scipy-notebook/data/cython/helloworld.pyx

@@ -0,0 +1 @@
+print("Hello World")

tests/scipy-notebook/data/cython/setup.py

@@ -0,0 +1,9 @@
+from setuptools import setup
+from Cython.Build import cythonize
+from pathlib import Path
+
+
+THIS_DIR = Path(__file__).parent.resolve()
+
+
+setup(ext_modules=cythonize(str(THIS_DIR / "helloworld.pyx")))

tests/scipy-notebook/test_cython.py

@@ -0,0 +1,36 @@
+# Copyright (c) Jupyter Development Team.
+# Distributed under the terms of the Modified BSD License.
+
+import logging
+from pathlib import Path
+import shutil
+import tempfile
+
+from conftest import TrackedContainer
+
+LOGGER = logging.getLogger(__name__)
+THIS_DIR = Path(__file__).parent.resolve()
+
+
+def test_cython(container: TrackedContainer) -> None:
+    data_dir = THIS_DIR / "data/cython"
+
+    with tempfile.TemporaryDirectory() as host_data_dir:
+        """We create temporary dir with the same content to mount it as a writeable folder
+        This allows to run this test in parallel many times
+        """
+        shutil.copy(data_dir / "helloworld.pyx", host_data_dir)
+        shutil.copy(data_dir / "setup.py", host_data_dir)
+
+        cont_data_dir = "/home/jovyan/data"
+        command = "sleep infinity"
+
+        running_container = container.run_detached(
+            volumes={str(host_data_dir): {"bind": cont_data_dir, "mode": "rw"}},
+            tty=True,
+            command=["start.sh", "bash", "-c", command],
+        )
+        command = f"python {cont_data_dir}/setup.py build_ext --inplace"
+        cmd = running_container.exec_run(command)
+        LOGGER.debug(cmd.output.decode("utf-8"))
+        assert cmd.exit_code == 0, f"Command {command} failed"