Three changes to the POS sale pipeline, all in one commit because
pos-service.ts / types.ts / pos-app.js are each touched by all three and
splitting them would only produce intermediate broken states.
VAT is now charged on top, not backed out
Catalogue prices are ex-VAT: `selling_price` is derived as
`cost_price x markup` from the supplier's ex-VAT cost, with no VAT
uplift anywhere (verified — median selling/cost across the catalogue is
exactly 1.8). The till nevertheless treated them as VAT-inclusive and
recovered the net with `total / 1.15`, so every sale was recorded with
an understated net and an understated VAT line.
An R100 ex-VAT line now rings up as R115. The rate comes from the till's
letterhead, read server-side rather than accepted off the wire, and is
stored per sale so a later letterhead rate change cannot rewrite what
was charged. All 3,623 catalogue prices are untouched.
Ad-hoc "custom" lines
A cashier can now ring up something that was never a catalogue item —
"bolt cutting" at R20 agreed at the counter — via a new
"+ Add a custom item" composer. The line prints on the slip and lands in
pos_sale_items, but carries no stock_item relation and takes no stock
movement: no ledger row, no current_qty decrement, no catalogue entry.
pos_sale_items.stock_item is no longer required at the schema level and
an explicit `is_custom` flag marks the line, rather than inferring it
from a blank relation — so "how much did we make on bolt cutting this
month" is a plain query, and a future stock-less line type cannot be
confused with a corrupt one.
Custom lines are refused on account sales: those raise a delivery note
the customer signs for and feed their statement, so an ad-hoc charge
must not slip onto one. Enforced server-side, not just in the UI.
Discounts are now 20% or 40%, nothing else
The R-off / %-off pills and the free-typed number box are gone. The
server treats DISCOUNT_PERCENT_OPTIONS as an allowlist and refuses
anything outside it rather than coercing it, so a stale till cannot
invent a discount. The discount lands on the ex-VAT subtotal, making
"20% off" a true 20% off both the net and the VAT on it.
Two defects found while doing this
pos_sales was missing six fields that checkoutSale has been writing all
along (gross_subtotal, gross_vat, gross_total, discount_amount,
discount_kind, discount_input). PocketBase accepts unknown fields
without error and silently drops them, so all 192 historical sales lack
them and a discounted sale reprinted as though no discount had been
applied. Added, plus vat_percent.
History also passed gross_total (VAT-inclusive) where the receipt
derives the gross VAT from an ex-VAT base — a reprint double-counted
VAT. Corrected.
Verification: 3860 tests pass (14 new); typecheck, lint and production
build clean; live PocketBase probe confirms a pos_sale_items row with
stock_item="" and is_custom=true round-trips, with the probe removed
afterwards.
Ringing up 800 of something means typing 800, and the only route to the
quantity field was a 600ms long-press with no affordance anywhere on
screen. The quantity itself — the thing a cashier reaches for — was a
plain <div class="v">, so it rendered inert.
- the quantity is now a real button that opens the Edit line sheet,
with an aria-label and a 44px touch target (it was 30px, too narrow
to even show "800")
- holding +/- no longer pops the sheet open mid-tap: the pointerdown
handler bails for .qty/.rm before starting the timer
- the sheet is quantity-only. The Unit price field is gone on request;
a mis-keyed price is expensive and easy to miss. The per-line
override it fed is removed with it — pos-service.ts only ever read
unit_price, the "price edited" label and the sale record's `edited`
flag were unreachable, and nothing else could set an override,
including a cart reload (persistCart saves only {id, qty, p})
The discount trigger moved out of its own 54px footer row to ride
inside the Subtotal row, so it costs no vertical height at all while
staying visible — a discount control that appears from nowhere is one
nobody finds under pressure. The applied-discount red totals row
remains the always-on indicator.
Fixes a pre-existing bug found while testing: long-pressing a cart row
showed a grey screen with no dialog. #editSheet is a SIBLING of
#editBackdrop, but the CSS revealed it with
`.edit-backdrop.show .edit-sheet` — a descendant selector that can
never match a sibling — so the sheet sat at opacity:0 while the
backdrop went opaque. Nothing threw and the build was green, which is
why it survived; it is also why manual quantity entry looked missing.
The sheet now has its own z-index above the backdrop and its own .show
rule. They stay siblings on purpose: nesting the sheet inside the
backdrop would make every tap on Save bubble to the backdrop's
onclick and close the dialog.
Verified in jsdom against the real markup: old CSS reproduces the grey
screen (backdrop opacity 1, sheet opacity 0, not clickable), the fix
clears it (sheet opacity 1, z-index 71 > 70, position fixed). 125 POS
tests pass, including 23 new ones asserting the tap target exists, the
long-press guard fires before the timer, the sheet stacks above its
backdrop, and the popup stays quantity-only.
sw.js v30 -> v33: pos-app.js and pos.html are both served cache-first out
of the shell, so without the bump tills keep the old ones.
