Running the tests

July 3, 2026 ยท View on GitHub

JustHTML uses the web platform html5 treebuilder tests to ensure parser compliance. These tests live in web-platform-tests/wpt; serializer and encoding tests remain in html5lib-tests. These tests are not included in the repository to keep it lightweight and to make updates easy.

Setup

  1. Clone the test repositories next to your justhtml directory:

    cd ..
git clone --filter=blob:none --sparse https://github.com/web-platform-tests/wpt.git
cd wpt
git sparse-checkout set html/syntax/parsing/resources
cd ..
git clone https://github.com/html5lib/html5lib-tests.git
cd justhtml

  2. Create symlinks in the tests/ directory:

    cd tests
ln -s ../../wpt/html/syntax/parsing/resources html5lib-tests-tree
ln -s ../../html5lib-tests/serializer html5lib-tests-serializer
ln -s ../../html5lib-tests/encoding html5lib-tests-encoding

Running tests

Once the symlinks are set up, you can run the tests using:

python run_tests.py

To run only one suite:

python run_tests.py --suite tree
python run_tests.py --suite justhtml
python run_tests.py --suite serializer
python run_tests.py --suite encoding
python run_tests.py --suite unit