Performance

[Matthew Phillips]

These are the levers to pull:

• querySelectorAll
  • Currently this happens on every update. How can we limit this to only when something has changed? Things that can invalidate qSA:
    • attr
    • class-toggle
    • each
    • attach-template
• Dirty check to see if values have changed.
  • Insertions need to be checked every time.
  • var() needs to be checked when a dependent query changes.
• matches
  • Similar to the qSA problem, checked on every render. Should skip if there isn't an invalidation.

[Matthew Phillips]

Most of these have been implemented (just not selector specificity). Will create another issue to benchmark.