This is a tool to collapse redundant clauses and rules in the WPT meta-files in mozilla-central.
git clone https://github.com/staktrace/supercollapser
cd supercollapser
./supercollapse /path/to/mozilla-central
This will make changes to the testing/web-platform/meta folder in your
mozilla-central folder. Diff to verify and commit.
The collapsing is done using a set of rules hard-coded in src/main.rs. It
needs to be updated if we add new test configurations and such. So always
do a try push with all configurations before landing the generated changes.
There is a big comment above the ruleset in src/main.rs that explains how
the rulesets work and walks through a concrete example.