23 August 2019

Taofeng(Tommy) Li
tests gsoc2019 standalone pypi pytest automation Nuitka

Intro

As Google Summer of Code (GSoC) is coming to an end, I am writing this blog post as a final summary describing all the work I have done as well as my experiences in this program.

Summary of My Work

• #314 run_all.py new special-comment mechanism & Urllib3Using.py

  • Before GSoC started, I looked around for whatever work I could help with.

  • In this pull request, I added a checkRequirements function for the Nuitka standalone test suite.

  • This function checks for special-comments at the top of standalone tests in the format of # nuitka-skip-unless-expression: expression to be evaluated OR # nuitka-skip-unless-imports: module1,module2,... and will decide whether to skip a test depending on if its specified requirements are met.

  • In addition, standalone test Urllib3Using.py was created.

  • This pull request was soon merged and allowed me the lucky opportunity of GSoC 2019 with Nuitka :)

• #339 Standalone tests for botocore & boto3 + fix to Urllib3Using.py

  • This PR was also created before the start of GSoC.

  • Standalone test Boto3Using.py was created using moto to mock AWS calls which did not turn out well.

  • Changed Urllib3Using.py with the addition of python version checks as a fix to Issue #373.

• Urllib3 Wheel with Nuitka Pytest Results and Python-Dateutil Wheel with Nuitka Pytest Results

  • At the start of GSoC, I performed manual pytest comparison for PyPI packages urllib3 and dateutil.

  • The findings of my testing were documented in these postings.

  • Manual testing compares the pytest results of an installed nuitka wheel built using python setup.py bdist_nuitka to the regular pytest results of each package.

  • Testing is done to ensure that nuitka is building the wheel correctly.

  • If the pytests pass/fail in the same way, that means Nuitka built the wheel properly.

  • Else if the tests differ, then something is wrong.

  • Virtualenv is used to create a clean environment with no outside pollution.

  • Over the course of performing manual testing, I became familiar with the use of virtualenv, wheel, and pytest.

  • A bug was found with the package urllib3 bdist and I created Issue #413 to document the bug.

• #440 Automating PyPI Wheel Pytest

  • After familiarizing myself with how virtualenv, wheel, and pytest work, I started to work on a script which would automate the pytest comparison for top PyPI packages.

  • The script first uses git to update each package if it is already existing in the local cache, else it will git clone that package into the local cache.

  • The script then uses calls to os.system to automate the creation of a virtualenv which is then used to install pytest and pip install the package’s requirements (if any) for running pytest.

  • The script then handles each package depending on different needs before building a regular wheel with python setup.py bdist_wheel.

  • This wheel is then installed into the virtualenv, after which subprocess.Popen is used to run and capture the output of python -m pytest --disable-warnings into a string.

  • The script then resets the package to its original state and builds a nuitka-compiled wheel using python setup.py bdist_nuitka.

  • This compiled wheel is then installed into the virtualenv, after which subprocess.Popen is used to run and capture the output of python -m pytest --disable-warnings into another string.

  • The two strings containing pytest outputs are then compared to find differences.

  • If no differences are found, this means bdist_nuitka worked properly. Else Nuitka compilation did something wrong.

  • The above process is repeated for each suitable PyPI package from the PyPI top 50. (Some packages are left out if they do not contain a test suite or if they do not need to be tested)

  • At the end, a colored summary is given for all the packages tested.

  • This automation script is meant to be run regularly to inform developers of Nuitka regressions.

• Issue #477 Unable to compile modules listed under unworthy_namespaces

  • Raised due to package pycparser failing in the automated test suite.

  • This issue will be addressed in the future.

• Issue #479 bdist_nuitka fails for packages containing py_modules only

  • While I worked on #440, I found a bug with bdist_nuitka failing on PyPI packages containing py_modules only.

  • This bug occurs due to Nuitka making the assumption that a main package always exists for all packages. However, some packages contain only a main module and not a main package.

  • Applies to PyPI packages decorator, ipaddress, and pyparsing.

• #483 Add support for py_modules_only compilation

  • This pull request changes bdist_nuitka.py and various other files to fix Issue #479.

  • Checks are added for the bdist_nuitka command to see if a main package exists. If there is not a main package, it will set its compile target to the main module instead.

  • This also addressed the case of a package with both a main package and a main module, in which case both are included inside the resulting wheel.

  • In addition, distutils examples py_modules_only and package_and_module were created and added for future testing.

  • During this PR, I found an import bug in Nuitka and hotfixed it with #487 Fixup_import_module.

• #484 PyPI Standalone Tests

  • This pull request adds more standalone tests for each top PyPI package.

• #495 Improve pypi automation

  • Improves the PyPI test suite created in #440 with functional improvements, readability improvements, and added documentation.

Things I Learned

Before GSoC, I was very uncomfortable with working inside a terminal. I was unfamiliar with many basic bash commands because I simply did not have any prior professional industrial experiences. I was also very unfamiliar with the Git flow, which is evident in the messy commit histories of my earliest pull requests.

As I continued throughout my GSoC journey, however, I became much more comfortable with working inside the terminal as well as using git as a version-control system (shoutout to my mentor Kay Hayen for helping me through all the annoying conflicts).

Although I am still no expert, I can confidently say that I am now far more proficient working with git and inside the terminal.

In addition, I became much more familiar with many of the most popular PyPI packages as well as the inner workings of python, which I believe will help me go very far in my career as a software developer.

Overall, the GSoC experience was truly astounding and I am more than thankful to my mentor Kay Hayen as well as Google for making this amazing program possible.

Yours, Tommy

Nuitka Release 0.6.5   bksahu’s GSoC warp up