rust_browser/.claude/commands/wpt.md

Manage WPT (Web Platform Tests) for the browser engine.

Command: $ARGUMENTS

Available commands

Parse the command from $ARGUMENTS and execute the appropriate action below. If the command is empty or "help", show the available commands summary.

run — Run the WPT test suite

1. Run the full WPT suite:

   cargo test -p rust_browser --test wpt_harness wpt_suite_matches_manifest_expectations -- --nocapture 2>&1
   

2. Parse the output to extract:
   • Total tests, pass count, known_fail count, pixel_promoted count
   • Any failures (lines after "WPT harness failures")
3. If there are pixel_promoted > 0 tests (known_fail cases that now pass), report them and suggest promoting with /wpt promote
4. If there are failures, report each one and categorize:
   • Unexpected failure: a pass case that failed — suggest demoting with /wpt demote
   • Unexpected pass: a known_fail case that passed — suggest promoting with /wpt promote
5. Summarize results in a table

promote <id> [<id>...] — Promote known_fail tests to pass

Promote tests that are now passing. For each ID:

1. First verify the test actually passes by running it:

   cargo test -p rust_browser --test wpt_harness wpt_suite_matches_manifest_expectations -- --nocapture 2>&1
   

   (You can skip this if you just ran /wpt run and confirmed the test passes)

2. For single mode tests, regenerate expected outputs:

   just regen-wpt
   

3. Update the manifest:

   just wpt-status promote --id <id1> --id <id2> ...
   

4. Run the suite again to confirm everything passes:

   cargo test -p rust_browser --test wpt_harness wpt_suite_matches_manifest_expectations -- --nocapture 2>&1
   

5. Report the results

demote <id> [<id>...] <reason> — Demote pass tests to known_fail

Demote tests that are now failing. Parse the arguments: all tokens that look like test IDs (contain "wpt-") are IDs, and the remaining text is the reason. If no reason is provided, ask the user for one.

1. Update the manifest:

   just wpt-status demote --id <id1> --id <id2> ... --reason "<reason>"
   

2. Run the suite to confirm the manifest is now consistent:

   cargo test -p rust_browser --test wpt_harness wpt_suite_matches_manifest_expectations -- --nocapture 2>&1
   

3. Report the results

status [<id>...] — Show status of specific tests

If IDs are provided:

just wpt-status show --id <id1> --id <id2> ...

If no IDs are provided, show a summary:

just wpt-status list --status pass 2>&1
just wpt-status list --status known_fail 2>&1
just wpt-status list --status skip 2>&1

Report a summary table with counts for each status.

list <pass|known_fail|skip> — List tests by status

just wpt-status list --status <status>

regen — Regenerate expected outputs for all single-mode pass tests

just regen-wpt

Report which files were regenerated.

Notes

• The WPT manifest is at tests/external/wpt/wpt_manifest.toml
• Test IDs typically look like wpt-css-* or wpt-reftest-* or wpt-known-fail-*
• The just wpt-status command wraps python3 scripts/wpt_status.py
• Tests run in parallel using std::thread::scope
• pixel_promoted in output means a known_fail reftest passed pixel comparison — these are candidates for promotion