Answers "which of my 100 tills are alive and healthy", and fixes three things
that were fine on one device and broken on a hundred.
Terminal identity (lib/data/local/terminal_identity.dart)
- Every device mints a UUID on first run, stored in its own database, plus a
short code (T4A9) derived from it. Renaming keeps the device id, so history
keeps pointing at the same physical till.
- Replaces the literal 'TERM-01', which was hardcoded in five places. The whole
fleet reported as one terminal: shift reports merged, MQTT topics collided,
and a second connection with the same client id evicts the first from the
broker — so two tills would have knocked each other offline in a loop.
Invoice numbers now carry the terminal code
- INV-2608-T4A9-00042. The sequence counter lives in each till's own database
and starts at 1, so without this every terminal in the fleet minted
INV-2608-00001 for its first sale of the month. The order UUID kept the data
distinct; the number a customer quotes on a receipt was not.
SQLite pragmas
- WAL, so the product grid refreshing does not block the sale being written,
and the file is never left mid-rewrite by a power cut.
- busy_timeout 5s, so a contended lock waits instead of throwing "database is
locked" — which at checkout is a failed sale with a customer standing there.
- synchronous NORMAL, the right trade under WAL for a till.
Fleet presence (lib/data/sync/presence_reporter.dart)
- Retained status record on connect and once a minute: device id, code, name,
app version, pending bill count, last upload, catalogue revision, sync halt
state. Retained so a dashboard connecting at noon gets all 100 terminals
immediately rather than a blank board.
- The Last Will already said "reachable". A till can be connected and still be
holding 200 unsent bills or running last month's prices; only pending_bills
and catalogue_revision say so.
NATS
- The MQTT gateway maps / to . so the existing transport works unchanged.
SyncConfig.asNatsSubject() exposes the translation, and the contract doc
gives the JetStream subjects (pos.*.*.order, pos.*.*.status) plus the two
server-side requirements: a file-backed stream, and the ack published by the
consumer after commit rather than by the ingest handler.
Tests: 129 -> 140. New coverage for identity minting and stability, per-device
invoice uniqueness, topic and client-id separation, NATS subject mapping, and
the two pragmas. Suite run three times clean.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Bills were persisted correctly but read back wrong. The read path rebuilt a
cart from its lines alone, dropping bill-level discounts and loyalty, so every
figure derived from a stored bill was overstated: the upload payload, the day
archive and the shift report. A discounted 529 bill read back as 620.
Money and data integrity
- order_dao: restore bill_discount and points_redeemed when rebuilding a cart;
keep the reconstruction tier-less so the membership discount is not applied
twice. Trust the recorded total and points via SaleTransaction.storedTotal.
- checkout_sale + order_dao.commitSale: write the bill, its stock movement and
the loyalty update in one transaction. Previously a failure part-way through
left a persisted bill the cashier believed had failed, inviting a duplicate.
- checkout_sale: re-check every line against live stock. A parked bill resumed
after its stock was sold passed validation and oversold.
- catalogue_dao: allocate the invoice sequence in one transaction; the previous
read-modify-write could hand two sales the same number and fail UNIQUE.
- local_store: replay unsynced sales after a catalogue import, so a mid-shift
re-import cannot restore stock that has already been sold.
- payment_controller: stamp the signed-in operator on the bill instead of the
hardcoded seed session, and pass the terminal id through.
- cart: reconcile per-slab GST against the bill total so the parts sum to the
whole on a tax invoice.
Sync and reporting
- sync_repository: drain unsynced bills in a loop rather than silently capping
at one page; stop on rejection so rejected rows cannot loop forever.
- sync_log_dao (new): persist the sync history to the sync_log table, which the
schema already defined but nothing used. It was in memory, so the only record
that bills had been uploaded died at restart.
- Scope shift reports by cashier. day_archive is re-keyed to
(business_date, cashier_name) so a till stays settleable after its bills are
uploaded and deleted. Schema v4 with a migration that carries v3 rows across.
Input and UI
- barcode_service: consume machine-paced keystrokes so a scan cannot also land
in the focused field, and raise the bar to 60ms/char while a text field has
focus so typing a mobile number is not read as a scan. Clock and focus check
injected so the behaviour is testable.
- primary_button: make the label flexible; label plus trailing total overflowed
the Charge button by up to 131px.
- app_router: redirect instead of null-casting when the receipt route is
entered without its transaction.
- customer_repository: reduce the search query to digits so a punctuated mobile
number matches.
Cleanup
- Remove TransactionRepository.save, CustomerRepository.recordSale and
OrderDao.insertOrder, all superseded by commitSale.
- dart fix across the tree; 251 analyzer issues down to 3 info-level.
Tests: 23 passing / 15 failing -> 90 passing. Fixed the two defects that broke
the existing suite (containsAll type argument, reset() needing a catalogue) and
deleted the leftover template test. Added coverage for the order round trip,
the day archive after a real sync, stock safety, checkout atomicity, the v3->v4
migration, scanner-versus-human input, and an app-level smoke test that renders
every module.
Note: bills already uploaded with a discount went up overstated. This stops it
happening again but does not correct historical server data.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
