"How long after eating did he poo?" is answerable from the log, but only by
reading two times off the screen and subtracting them — and the pair is often
on different days, so it is rarely on screen together at all. Hold one row,
hold another, and a bar along the bottom does the subtraction and keeps it
until you clear it, which is what lets you change day between the two picks.
Any row that is a single moment can be picked: history, notes, weigh-ins. Sleep
and walk rows cannot, being spans — measuring from one would need a rule about
which end, and a rule you have to remember is worse than the feature.
The picks are a module-level variable rather than storage. A measurement is a
question you are asking now, not a setting; but module-level is also what
carries it through the re-render a background sync causes every minute, which
would otherwise wipe a half-made measurement. Ids that stop resolving — deleted
here, tombstoned by another device — leave the pick on the next render instead
of lingering as half a pair.
Two additions beyond what was asked. Holding a picked row unpicks it: that is
not a third selection but an undo of one, and without it a mis-press costs a
clear. And the reading is ordered by time rather than by which was pressed
first, so it is always chronological and never negative — pressing upward
through a log is the natural way to read it.
The press mechanics are all load-bearing: a finger that travels is a scroll and
cancels, a fired press swallows the click that would otherwise also open the
edit dialog, and the platform's own long-press menu is suppressed. That last
part needs user-select: none on the rows, which costs the ability to select a
note's text to copy. Worth stating plainly — it is a real loss, taken because
holding a row now means something else.
checks/extract.mjs gained getters for mutable bindings while writing the checks
for this. It only ever returned a let's value at load time, so measurePick went
stale the moment the code reassigned it and the checks were quietly asserting
against a snapshot. Any future check reading a mutable binding would have hit
the same thing.
The server has go test; the frontend had nothing, and the things most likely to
break there are the ones hardest to see: the arithmetic behind the charts, a
panel lost while shuffling tabs, a label that truncates on a phone none of us
owns. There is no browser in this loop, so these are what can be checked
without one.
They read the real code rather than copying it. The app is one long IIFE with
nothing exported, and adding a module system or a build step to make it
testable would be a large change in service of a small one — so
checks/extract.mjs reads src/app.js, brace-matches the declarations a check
asks for, and evaluates them. Rename a function and it throws by name. A check
quietly exercising a stale copy of the code would be worse than no check, and
that is the failure mode this avoids.
calendarGridStart is pulled out of renderCalendar as part of this. It is the
one line of the month grid that is easy to get wrong and impossible to notice
— a month starting on the week's first day needs no backing up, one starting
the day before needs six — so it earns a name and a test.
The width figures are estimates, not measurements: layout numbers come out of
style.css so they cannot drift, text is sized from per-character advances, and
the pass mark demands a few pixels of headroom because the estimate is only
good to a few percent. They will catch a sixth tab or a longer label. They will
not settle a two-pixel question, and nothing here replaces looking at a phone.
No new dependencies: nodejs is already in the devShell for `node --check`, and
checks/ sits outside src/ so it is not served with the app.
Alexander Heldt