This page is testing different task sources priorities

Algorithm

from @artalog

• [1] schedule a wrong fetch
• [2] schedule setTimeout 0
• [3] schedule requestAnimationFrame
• [0.1] queueMicrotask
• [0.2] change observable attribute
• block JS loop for 2 seconds (red bg)
• [4] catch YOUR click
• for each log schedule additional microtask
• unlock the loop and print logs
• see that the order of tasks and microtasks is not the same as it schedule order

See also the spec