This video almost shipped broken

The exact clicks

1. Before trusting any automated check, feed it a case you already know is broken.
2. Confirm the check actually flags that known-bad case — not just that it runs without error.
3. Only then trust it on real, unknown cases.
4. Re-run this test after any change to the check itself, not just after changes to what it checks.

What changes

• A level check measured the wrong thing — it read a position in the file, not whether the sound had actually landed.
• A check ran before the fix it was supposed to verify, so it always passed.
• A script proved a file existed by checking its path, not its contents — the file was empty.
• None of these three were caught by a tool. A person listening, reading, and checking by hand caught all three.

What it will not do

• Testing a check against a known-bad case does not guarantee it catches every bad case — only the ones like the one you tested.
• This is a discipline, not a one-time fix. The three defects here happened after checks already existed; the checks just weren't checked.