fix(bank): Swedish provider errors and a durable failure trail for bank connect attempts (#1841)

Issue #1716: a user stuck in Handelsbankens fullmakt step got a raw
provider token back (server_error, invalid_state) and support had nothing
to look at afterwards: the failed pending row is deleted by design, the
callback only logged to console (short retention), and event_log recorded
successes only. Diagnosis of the reported case: the failures were on the
bank's side (the corporate fullmakt requirement); both of the reporter's
companies connected successfully on 2026-08-12 with no code change on our
side in between, and the connections have been active and syncing since.

Changes:
- lib/errors/get-error-message.ts: getBankConnectionErrorMessage() maps
  PSD2 callback outcomes (access_denied, server_error,
  temporarily_unavailable, session expiry, plus the internal
  invalid_state, missing_parameters and invalid_code_format tokens) to
  Swedish user messages, appending the raw provider description so the
  underlying error is still surfaced.
- callback route: every bank_error redirect and the stored error_message
  now carry the mapped Swedish text; bank_error_code, bank_name and
  psu_type still flow so the settings page keeps its targeted guidance
  (Handelsbanken fullmakt steps included).
- New audit events bank_connection.consent_denied and
  bank_connection.finalize_failed are emitted on the two failure paths
  and persisted to event_log, so support can answer which attempt failed,
  with which provider error, on whose side, even after the row is gone.


Claude-Session: https://claude.ai/code/session_01SyDuePXxUFowaPBKpAv8SF

Co-authored-by: Jakob Wennberg <311770904+jakobwennberg-oss@users.noreply.github.com>
Co-authored-by: Claude Fable 5 <noreply@anthropic.com>
This commit is contained in:
Jakob Wennberg
2026-08-26 09:35:26 +02:00
committed by GitHub
co-authored by Jakob Wennberg Claude Fable 5
parent 1307d4db2e
commit 64119d30bc
6 changed files with 335 additions and 17 deletions
@@ -65,6 +65,7 @@ vi.mock('@/lib/cash-accounts/service', () => ({
vi.stubEnv('NEXT_PUBLIC_APP_URL', 'http://localhost:3000')
import { GET } from '../route'
import { eventBus } from '@/lib/events/bus'
function makeRequest(params: Record<string, string>) {
const url = new URL('http://localhost:3000/api/extensions/enable-banking/callback')
@@ -122,7 +123,9 @@ describe('GET /api/extensions/enable-banking/callback', () => {
expect(response.status).toBe(307)
const location = response.headers.get('location') || ''
expect(location).toContain('/settings/banking?')
expect(location).toContain('bank_error=invalid_state')
// The raw 'invalid_state' token used to be shown verbatim: the banner now
// carries the Swedish explanation instead (issue #1716).
expect(decodeURIComponent(location)).toContain('Starta bankkopplingen på nytt')
})
it('writes pending_selection and streams a finalizing page that redirects to the picker', async () => {
@@ -1085,7 +1088,9 @@ describe('GET /api/extensions/enable-banking/callback', () => {
expect(response.status).toBe(307)
const location = response.headers.get('location') || ''
expect(location).toContain('/settings/banking?')
expect(location).toContain('bank_error=User%20cancelled')
// The user-facing message is Swedish; a cancel is an expected outcome, so
// the raw provider text is not echoed back.
expect(decodeURIComponent(location)).toContain('Anslutningen avbröts hos banken')
// No state → no DB cleanup attempted
expect(mockFrom).not.toHaveBeenCalled()
})
@@ -1104,7 +1109,7 @@ describe('GET /api/extensions/enable-banking/callback', () => {
expect(response.status).toBe(307)
const location = response.headers.get('location') || ''
expect(location).toContain('/settings/banking?')
expect(location).toContain('bank_error=Denied%20data%20sharing%20consent')
expect(decodeURIComponent(location)).toContain('Anslutningen avbröts hos banken')
// Should clean up the pending row
expect(mockFrom).toHaveBeenCalledWith('bank_connections')
})
@@ -1138,7 +1143,9 @@ describe('GET /api/extensions/enable-banking/callback', () => {
const location = response.headers.get('location') || ''
// URLSearchParams encodes spaces as '+', unlike the encodeURIComponent
// fallback used when no matching row exists.
expect(location).toContain('bank_error=User+cancelled')
expect(decodeURIComponent(location.replace(/\+/g, ' '))).toContain(
'Anslutningen avbröts hos banken'
)
expect(deleteCalls).toHaveLength(1)
expect(updateCalls).toHaveLength(0)
})
@@ -1172,6 +1179,10 @@ describe('GET /api/extensions/enable-banking/callback', () => {
expect(deleteCalls).toHaveLength(0)
expect(updateCalls).toHaveLength(1)
expect(updateCalls[0].status).toBe('expired')
// The stored error_message is user-facing on the connection card: Swedish
// explanation with the raw provider description surfaced in parentheses.
expect(updateCalls[0].error_message).toContain('inloggningssession')
expect(updateCalls[0].error_message).toContain('Session expired at ASPSP')
})
it('forwards bank_error_code and psu_type when the denied state matches a pending connection', async () => {
@@ -1190,8 +1201,9 @@ describe('GET /api/extensions/enable-banking/callback', () => {
expect(response.status).toBe(307)
const location = response.headers.get('location') || ''
expect(location).toContain('/settings/banking?')
// error_description is null for server_error, so the code doubles as message
expect(location).toContain('bank_error=server_error')
// A bare server_error used to surface as the literal token; the banner
// now gets the Swedish explanation (issue #1716).
expect(decodeURIComponent(location.replace(/\+/g, ' '))).toContain('fel på bankens sida')
expect(location).toContain('bank_name=Handelsbanken')
// The code is forwarded for every error, not just access_denied, together
// with the connection's psu_type — the settings page keys the Handelsbanken
@@ -1206,7 +1218,7 @@ describe('GET /api/extensions/enable-banking/callback', () => {
expect(response.status).toBe(307)
const location = response.headers.get('location') || ''
expect(location).toContain('/settings/banking?')
expect(location).toContain('bank_error=missing_parameters')
expect(decodeURIComponent(location)).toContain('ofullständigt svar')
})
it('redirects with error when code fails format validation', async () => {
@@ -1215,6 +1227,85 @@ describe('GET /api/extensions/enable-banking/callback', () => {
expect(response.status).toBe(307)
const location = response.headers.get('location') || ''
expect(location).toContain('/settings/banking?')
expect(location).toContain('bank_error=invalid_code_format')
expect(decodeURIComponent(location)).toContain('ogiltigt svar')
})
it('emits a durable consent_denied audit event when the bank denies with a matching row', async () => {
const emitSpy = vi.spyOn(eventBus, 'emit').mockResolvedValue(undefined)
try {
mockFrom.mockImplementation(() =>
mockChain({
data: {
id: 'conn-1',
user_id: 'user-1',
company_id: 'company-1',
bank_name: 'Handelsbanken',
psu_type: 'business',
status: 'pending',
},
error: null,
})
)
const response = await GET(makeRequest({
error: 'server_error',
error_description: 'ASPSP authorization failed',
state: 'pending-state',
}))
expect(response.status).toBe(307)
expect(emitSpy).toHaveBeenCalledWith({
type: 'bank_connection.consent_denied',
payload: {
connectionId: 'conn-1',
bankName: 'Handelsbanken',
psuType: 'business',
errorCode: 'server_error',
errorDescription: 'ASPSP authorization failed',
priorStatus: 'pending',
userId: 'user-1',
companyId: 'company-1',
},
})
} finally {
emitSpy.mockRestore()
}
})
it('emits a durable finalize_failed audit event when the session exchange fails', async () => {
const emitSpy = vi.spyOn(eventBus, 'emit').mockResolvedValue(undefined)
try {
mockFrom.mockImplementation(() =>
mockChain({
data: {
id: 'conn-1',
user_id: 'user-1',
company_id: 'company-1',
bank_name: 'TestBank',
status: 'pending',
},
error: null,
})
)
mockCreateSession.mockRejectedValue(new Error('upstream timeout'))
const response = await GET(makeRequest({ code: 'auth-code', state: 'valid-state' }))
expect(response.status).toBe(200)
await response.text()
expect(emitSpy).toHaveBeenCalledWith({
type: 'bank_connection.finalize_failed',
payload: {
connectionId: 'conn-1',
bankName: 'TestBank',
reason: 'upstream timeout',
priorStatus: 'pending',
userId: 'user-1',
companyId: 'company-1',
},
})
} finally {
emitSpy.mockRestore()
}
})
})