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Let everyone on a trip see it, and give payments their scope back
ci / lint-test (push) Successful in 52s
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Trips were scoped to trips.owner_id, so Sonu saw no trips at all — despite
having paid for 104 of the tagged rows herself. Her own spending was invisible
on the only page organised around it.

A participant is now anyone with a split on, who paid for, or whose payment is
scoped to, a transaction tagged to the trip. Derived, not stored. A
trip_participants table was designed and rejected: the expenses already carry
the fact, and two records of one fact drift apart. Deriving it also excludes
Singapore + Bangkok 2026 from Sonu for free, which a table would have to be kept
in sync to do. Siddharth 4 trips, Sonu 3, Molina 1.

Everything about a trip is shared except delete. Both trip foreign keys are
ON DELETE SET NULL, so deleting Europe 2026 untags 210 transactions and NULLs
the trip scope on 6 payments — where the hand-derived Europe-first allocation
lives, which nothing recomputes. That stays with the owner.

Trip owed now returns both directions and nets neither. An obligation lives on a
row someone else paid for, so a viewer-as-payer figure can never hold it, and
Sonu's Europe read "you are owed $2,408.24" while omitting the $8,004.04 she
owed. Collapsing the two into a signed net is the tempting next step and would
have corrupted the scope allocation: the grouped-payment allocation cleared each
trip against the one-directional gross, so redefining the debt afterwards turns
$8,004.04 already allocated into an $802.75 over-allocation with household
understated by the same amount. Verified byte-identical — Auckland $1,505.64,
Europe Molina -$816.16, Europe Sonu $0.00, Sonu + Sunny $0.00.

getTransactions gained trip_all_rows so a participant sees the whole trip. It is
opt-in and not implied by trip_id, because the same endpoint backs the main
transactions list and its trip filter must keep owner scoping. Participation is
re-checked in SQL, so passing the flag for someone else's trip returns nothing.

Payments can finally say what they settle. trip_id has existed since migration
0022 but POST never read it and GET never returned it, so every payment made in
the app landed on household and the 9 trip-scoped rows were hand-written SQL.
"Both" needs no new shape — one row per scope sharing a linked_transaction_id.

Three write paths had no authorisation at all and were reachable by any
participant: assignTransactionsToTrip checked nothing, DELETE on a payment
deleted by bare id, and POST accepted any from/to pair. All three now check.

Also fixes the test suite, which was pointing at postgres-pantry: container IPs
move on recreation and 172.22.0.47 stopped being postgres-personal. It only
failed safe because the credentials did not match — resetDB now refuses to
truncate anything not named personal_test.

22 new tests, 276 passing, build clean.
This commit is contained in:
siddharthd
2026-08-02 19:11:19 +10:00
parent 6e179d3a0a
commit cb7665ded1
13 changed files with 904 additions and 78 deletions
Download Patch File Download Diff File Expand all files Collapse all files
src/app/trips/[id]/page.tsx
+65 -20
View File
@@ -21,6 +21,10 @@ function fmtDate(d: string | null) {
return new Date(d).toLocaleDateString("en-AU", { day: "2-digit", month: "short", year: "numeric" });
}
function fmt(n: number) {
return `$${n.toLocaleString("en-AU", { minimumFractionDigits: 2, maximumFractionDigits: 2 })}`;
}
function StatCard({
label,
value,
@@ -73,7 +77,10 @@ export default function TripDetailPage({ params }: { params: Promise<{ id: strin
const [tab, setTab] = useState<"overview" | "transactions">("overview");
const [editModal, setEditModal] = useState(false);
const { data: txData } = useTransactions({ trip_id: id, limit: 500 });
// A trip is all the expenses on one trip, so a participant sees every row on
// it, not only their own. The server re-checks participation — this flag is a
// request, not a grant.
const { data: txData } = useTransactions({ trip_id: id, limit: 500, trip_all_rows: true });
if (isLoading || !analytics) {
return (
@@ -280,7 +287,7 @@ export default function TripDetailPage({ params }: { params: Promise<{ id: strin
<table className="w-full text-sm">
<thead>
<tr className="border-b border-zinc-800">
{["Person", "Outstanding on this trip"].map((h) => (
{["Person", "They owe you", "You owe them"].map((h) => (
<th
key={h}
className={`px-5 py-2.5 text-xs text-zinc-500 font-medium ${h === "Person" ? "text-left" : "text-right"}`}
@@ -291,30 +298,68 @@ export default function TripDetailPage({ params }: { params: Promise<{ id: strin
</tr>
</thead>
<tbody>
{/* A negative outstanding means they have paid more towards this
trip than their share of it — which reads as a typo unless the
sign is spelled out. Shown as a magnitude plus a word, the same
way Shared does it, so the two pages agree on what a direction
means. */}
{/* Two columns, never one net figure.
The two directions are separate positions, not halves of a
sum: the grouped-payment allocation cleared each trip against
the one-directional debt in the left column, Europe first with
the remainder to household. Netting them here would redefine
that debt after the fact and turn a settled trip into an
overpayment, with household understated by the same amount.
It is also what makes this page true for a non-owner. The
right-hand column is the figure Sonu could never see: her own
obligation lives on rows someone else paid for, so a
viewer-as-payer figure can never contain it.
A negative outstanding still means they have paid more towards
this trip than their share, which reads as a typo unless the
sign is spelled out — so it stays a magnitude plus a word, the
same way Shared does it. */}
{participant_splits.map((p) => {
const owed = Number(p.owed);
const square = Math.abs(owed) < 0.005;
const theyOweMe = owed > 0;
const iOwe = Number(p.i_owe);
const cell = (
net: number,
gross: number,
paid: number,
unconverted: number,
colour: string,
) => {
if (gross < 0.005 && Math.abs(net) < 0.005) {
return <span className="text-zinc-600">—</span>;
}
const square = Math.abs(net) < 0.005;
return (
<>
<span className={square ? "text-zinc-500" : net > 0 ? colour : "text-emerald-400"}>
${Math.abs(net).toFixed(2)}
</span>
<span className="block text-[11px] text-zinc-500 mt-0.5 font-sans">
{square
? "settled"
: net < 0
? "overpaid"
: paid > 0.005
? `${fmt(gross)} less ${fmt(paid)} paid`
: "outstanding"}
</span>
{unconverted > 0 && (
<span className="block text-[11px] text-amber-500/80 mt-0.5 font-sans">
approx · {unconverted} unconverted
</span>
)}
</>
);
};
return (
<tr key={p.participant_id} className="border-b border-zinc-800/50 last:border-0">
<td className="px-5 py-3 font-medium">{p.name}</td>
<td className="px-5 py-3 text-right tabular-nums font-mono">
<span className={square ? "text-zinc-500" : theyOweMe ? "text-amber-400" : "text-blue-400"}>
${Math.abs(owed).toFixed(2)}
</span>
<span className="block text-[11px] text-zinc-500 mt-0.5 font-sans">
{square ? "all square" : theyOweMe ? "owes you" : "ahead — you owe them"}
</span>
{p.unconverted_count > 0 && (
<span className="block text-[11px] text-amber-500/80 mt-0.5 font-sans">
approx · {p.unconverted_count} unconverted
</span>
)}
{cell(owed, Number(p.owed_gross), Number(p.paid_to_me), p.unconverted_count, "text-amber-400")}
</td>
<td className="px-5 py-3 text-right tabular-nums font-mono">
{cell(iOwe, Number(p.i_owe_gross), Number(p.paid_by_me), p.i_owe_unconverted_count, "text-blue-400")}
</td>
</tr>
);