CI: adding tox and testing

Author: bsipocz

tox.ini

@@ -0,0 +1,61 @@
+[tox]
+envlist =
+    py{311, 312, 313}-test{,-oldestdeps,-devdeps,-predeps}{,-buildhtml}
+requires =
+    pip >= 19.3.1
+
+[testenv]
+
+description = run tests
+
+setenv =
+    devdeps: PIP_EXTRA_INDEX_URL =  https://pypi.anaconda.org/scientific-python-nightly-wheels/simple
+
+passenv = CI, CIRCLECI, GITHUB_EVENT_NAME, GITHUB_EVENT_PATH
+
+deps =
+    # We use these files to specify all the dependencies, and below we override
+    # versions for specific testing schenarios
+    -rrequirements.txt
+    #-rsite_requirements.txt
+    #-r.binder/requirements.txt
+
+    # Notebooks may set minimums for some dependencies, the others are set for a supported minimum
+    # following e.g. SPEC0 or some other considerations.
+    oldestdeps: numpy==1.24.0
+    oldestdeps: matplotlib==3.7.0
+
+    # TODO: add pure python dependency, so we can add an example for the github install
+    devdeps: git+https://github.com/astropy/pyvo.git#egg=pyvo
+
+allowlist_externals = bash, sed
+
+commands =
+    pip freeze
+
+    ## Some of the these could be factored out to a separate shell script,
+    ## but so far it's simple enought to keep it here.
+
+
+    # Ignore testing the tutorials listed in ignore_testing file. We have some OS specific ignores,
+    # too due to issues with e.g. multiprocessing and problems in upstream dependency
+    !buildhtml: bash -c 'if python -c "import platform; print(platform.platform())" | grep -i macos; then cat ignore_osx_testing >> ignore_testing; fi'
+    !buildhtml: bash -c 'if python -c "import platform; print(platform.platform())" | grep -i win; then cat ignore_windows_testing >> ignore_testing; fi'
+
+    !buildhtml: bash -c 'if [[ $CI == true ]]; then cat ignore_gha_testing >> ignore_testing; fi'
+
+    # We only want to run CI in PRs for the notebooks we touched
+    !buildhtml: bash -c 'if [[ $GITHUB_EVENT_NAME == pull_request && -z "$(grep force_run:all_tests ${GITHUB_EVENT_PATH})" ]]; then git fetch origin main --depth=1; git diff origin/main --name-only tutorials | grep .md; else find tutorials -name "*.md"; fi | grep -vf ignore_testing | xargs jupytext --to notebook '
+
+    !buildhtml: pytest --nbval-lax -vv --suppress-no-test-exit-code --durations=10 tutorials
+
+    buildhtml: sphinx-build -b html . _build/html -nWT --keep-going
+    # SED magic to remove the toctree captions from the rendered index page while keeping them in the sidebar TOC
+    buildhtml: sed -E -i.bak '/caption-text/{N; s/.+caption-text.+\n<ul>/<ul>/; P;D;}' _build/html/index.html
+    buildhtml: bash -c 'rm _build/html/index.html.bak'
+
+pip_pre =
+    predeps: true
+    !predeps: false
+
+skip_install = true