[ummarig]

Assigned issues

Issue	Title	Status in this PR
#1502	[Stellar] Add contract ID checksum and format validation	Implemented
#1504	[Frontend] Add locale-aware date and time formatting	Not implemented
#1505	[Frontend] Add translation completeness checks for dynamic errors	Not implemented
#1507	[Frontend] Add wallet disconnect state recovery	Implemented

Per the assignment, this PR implements 2 of the 4 assigned issues. The two not
implemented are referenced with Closes so tracking stays accurate, but they are
not fixed here and a maintainer should close them manually rather than relying
on the merge.

On the two not implemented

• [Frontend] Add locale-aware date and time formatting #1504 (locale-aware dates): touches five or more components —
  receipts/[txHash]/page.tsx, BasisPointsPieChart.tsx,
  CreateSplitWizardLegacy.tsx, DashboardView.tsx, ManageSplitView.tsx — and
  needs a per-locale formatting policy agreed with product. Standardising these in
  one pass without that decision risks changing how every timestamp in the product
  renders.
• [Frontend] Add translation completeness checks for dynamic errors #1505 (translation completeness): already implemented on main.
  frontend/scripts/check-i18n-keys.mjs checks locale parity against the base
  locale, empty values, required wizard validation keys, and placeholder-argument
  matching ({remaining}, {over}). Running it against the current tree shows
  en and fr at 38 keys each with zero drift in either direction.

---

#1502 — contract ID checksum and format validation

The problem

CONTRACT_ID was validated with a regex and nothing else:

.regex(/^C[A-Z2-7]{55}$/, "CONTRACT_ID must be a valid Stellar contract address");

That is a format check, not a validity check. A Stellar StrKey carries a
trailing CRC-16 checksum over its own payload, so a value can satisfy the regex
perfectly and still be rejected by the network. The failure surfaced late and
opaquely: startup succeeded, the process came up healthy, and then the first real
call returned "contract not found".

The fix

Adds StrKey.isValidContract alongside the existing regex. The regex is kept
deliberately, so the two failure modes produce different messages — wrong shape
versus well-formed-but-checksum-mismatched — because they need different advice.

The checksum message says what to do rather than restating the constraint:

Copy it from the explorer or stellar contract list rather than transcribing it
— a single wrong character passes a format check and then fails on-chain.

must match /^C[A-Z2-7]{55}$/ does not help anyone diagnose a typo. The single
wrong character is the actual cause.

Test fixtures

Two existing fixtures were well-formed but checksum-invalid, and both call
validateEnv(), so they would have failed on this change:

File	Old value	Verdict
backend/src/config/env.test.ts	C + 55 As	checksum 0000, computed 5cc8
backend/src/__tests__/cors.test.ts	CBLASIRZ7C…H2LR	checksum mismatch

Both are replaced with StrKey.encodeContract(Buffer.alloc(32, 7)) rather than
hand-written literals, so the fixture cannot drift from what a real contract ID
looks like. This is the same call splits.compatibility.test.ts:16 already uses.

database.test.ts and database-pool-exhaustion.test.ts carry the same invalid
value but never call validateEnv() — they only stub process.env. They are
left alone; changing them would be unrelated churn.

#1507 — wallet disconnect state recovery

The problem

Account changes were handled. Disconnects were silently dropped.

if (fresh.connected && fresh.address !== state.wallet.address) {

When the user disconnects, fresh.connected is false, so the condition is
false and nothing dispatches. State keeps connected: true and the previous
address indefinitely.

Three consequences:

1. Stale balances stay on screen, belonging to an account the user has left.
2. Actions scoped to the old account stay reachable.
3. The reconnect toast in wallet-provider.tsx can never fire — it keys off
   !walletState.wallet.connected, which is exactly the flag that was never
   updated.

This is not caught by a second listener: lib/wallet.ts registers no wallet event
listeners at all, so this 2s poll is the only thing watching for the change.

The fix

Flips the guard so a disconnect takes the same RESET path as a switch:

if (!fresh.connected || fresh.address !== state.wallet.address) {

RESET returns initialState (connected: false, address: null), which clears
the stale balances. Account-switch handling is unchanged.

---

Files changed

File	Issue
backend/src/config/env.ts	#1502
backend/src/config/env.test.ts	#1502 (fixture)
backend/src/__tests__/cors.test.ts	#1502 (fixture)
frontend/src/hooks/useWallet.ts	#1507

The two fixture files are unavoidable: they call validateEnv(), so leaving them
would mean shipping a change that breaks the existing suite.

Verification

Dependencies are not installed and no tests were executed, per the task
constraint. Verified by inspection:

• @stellar/stellar-sdk@14.6.1 is a backend dependency and StrKey is already
  imported by backend/src/schemas/user.schemas.ts.
• Fixtures that call validateEnv() were found by grepping every CONTRACT_ID
  literal in backend/src — database.test.ts,
  database-pool-exhaustion.test.ts, deploy-config.test.ts and
  utils/deploy-config.test.ts do not, and were left untouched.
• The invalid-checksum claim was confirmed by re-implementing StrKey's CRC-16
  decode and checking each fixture against its own payload.
• lib/wallet.ts registers no event listeners, confirming the poll is the sole
  detection path.
• SIMULATOR_ACCOUNT: "test_account" is validated with .min(1) only, so the
  cors.test.ts env block is otherwise unaffected.

Closes #1502
Closes #1504
Closes #1505
Closes #1507

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You can now already apply to more issues while waiting for a review of this PR. Keep up the great work! 🚀

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[SheyeJDev]

LGTM