pypdf uses pytest for testing.

To run the tests you need to install the CI (Continuous Integration) requirements by running pip install -r requirements/ci.txt or pip install -r requirements/ci-3.11.txt if running Python ≥ 3.11.

Deselecting groups of tests

pypdf makes use of the following pytest markers:

  • slow: Tests that require more than 5 seconds.

  • samples: Tests that require the the sample-files git submodule to be initialized. As of October 2022, this is about 25 MB.

  • enable_socket: Tests that download PDF documents. They are stored locally and thus only need to be downloaded once. As of October 2022, this is about 200 MB.

    • To successfully run the tests, please download most of the documents beforehand: python -c "from tests import download_test_pdfs; download_test_pdfs()"

You can disable them by pytest -m "not enable_socket" or pytest -m "not samples". You can even disable all of them: pytest -m "not enable_socket" -m "not samples" -m "not slow".

Please note that this reduces test coverage. The CI will always test all files.

Creating a Coverage Report

If you want to get a coverage report that considers the Python version specific code, you can run tox.

As a prerequisite, we recommend using pyenv so that you can install the different Python versions:

pyenv install pypy3.8-7.3.7
pyenv install 3.7.15
pyenv install 3.8.12
pyenv install 3.9.10
pyenv install 3.10.2

Then you can execute tox which will create a coverage report in HTML form in the end. The execution takes about 30 minutes.

Docstrings in Unit tests

The first line of a docstring in a unit test should be written in a way that you could prefix it with “This tests ensures that …”, e.g.

  • Invalid XML in xmp_metadata is gracefully handled.

  • The identity is returning its input.

  • xmp_modify_date is extracted correctly.

This way, plugins like pytest-testdox can generate really nice output when the tests are running. This looks similar to the output of mocha.js.

If the test is a regression test, write

This test is a regression test for issue #1234

If the regression test is just one parameter of other tests, then add it as a comment for that parameter.

Evaluate a PR in-progress version

You may want to test a version from a PR which has not been released yet. The easiest way is to use pip and install a version from git:

a) Go the PR and identify the repository and branch.

Example from below : repository: pubpub-zz / branch: iss2200 : PR Header example

b) you can then install the version using pip from git:


pip install git+https://github.com/pubpub-zz/pypdf.git@iss2200