feat: enhance error handling and logging for bank connection process (#44)

app/api/extensions/enable-banking/callback/__tests__/route.test.ts

@@ -91,12 +91,32 @@ describe('GET /api/extensions/enable-banking/callback', () => {
     expect(location).toContain('connection_id=conn-1')
   })
 
-  it('redirects with error when bank returns error param', async () => {
+  it('redirects with error when bank returns error param (no state)', async () => {
     const response = await GET(makeRequest({ error: 'access_denied', error_description: 'User cancelled' }))
 
     expect(response.status).toBe(307)
     const location = response.headers.get('location') || ''
     expect(location).toContain('bank_error=User%20cancelled')
+    // No state → no DB cleanup attempted
+    expect(mockFrom).not.toHaveBeenCalled()
+  })
+
+  it('cleans up pending connection when bank returns error with state', async () => {
+    mockFrom.mockImplementation(() =>
+      mockChain({ data: null, error: null })
+    )
+
+    const response = await GET(makeRequest({
+      error: 'access_denied',
+      error_description: 'Denied data sharing consent',
+      state: 'pending-state',
+    }))
+
+    expect(response.status).toBe(307)
+    const location = response.headers.get('location') || ''
+    expect(location).toContain('bank_error=Denied%20data%20sharing%20consent')
+    // Should clean up the pending row
+    expect(mockFrom).toHaveBeenCalledWith('bank_connections')
   })
 
   it('redirects with error when code or state is missing', async () => {

app/api/extensions/enable-banking/callback/route.ts

@@ -22,7 +22,44 @@ export async function GET(request: Request) {
 
   if (error) {
     const errorMessage = errorDescription || error
-    console.error('Bank authorization error:', errorMessage)
+    console.error('[enable-banking] Bank authorization denied', {
+      error,
+      error_description: errorDescription,
+      has_state: !!state,
+    })
+
+    // Clean up the pending bank_connections row so it doesn't accumulate
+    if (state) {
+      try {
+        const supabase = await createServiceClient()
+
+        // Fetch connection details for logging before updating
+        const { data: pendingConn } = await supabase
+          .from('bank_connections')
+          .select('id, user_id, bank_name')
+          .eq('oauth_state', state)
+          .eq('status', 'pending')
+          .single()
+
+        if (pendingConn) {
+          console.error('[enable-banking] Authorization denied details', {
+            connection_id: pendingConn.id,
+            user_id: pendingConn.user_id,
+            bank_name: pendingConn.bank_name,
+            error_code: error,
+            error_description: errorDescription,
+          })
+
+          await supabase
+            .from('bank_connections')
+            .update({ status: 'error', error_message: errorMessage, oauth_state: null })
+            .eq('id', pendingConn.id)
+        }
+      } catch (cleanupError) {
+        console.error('[enable-banking] Failed to clean up pending bank connection:', cleanupError)
+      }
+    }
+
     return NextResponse.redirect(
       `${baseUrl}/settings?bank_error=${encodeURIComponent(errorMessage)}`
     )

extensions/general/enable-banking/index.ts

@@ -92,6 +92,35 @@ export const enableBankingExtension: Extension = {
 
           const psuType = companySettings?.entity_type === 'aktiebolag' ? 'business' : 'personal'
 
+          log.info('[enable-banking] Starting bank connection', {
+            user_id: user.id,
+            bank: aspsp_name,
+            country: aspsp_country,
+            entity_type: companySettings?.entity_type,
+            psu_type: psuType,
+          })
+
+          // Clean up any stale pending connections for this user+bank
+          // to avoid conflicts with the new authorization
+          const { data: staleConnections } = await supabase
+            .from('bank_connections')
+            .select('id')
+            .eq('user_id', user.id)
+            .eq('bank_name', aspsp_name)
+            .eq('status', 'pending')
+
+          if (staleConnections && staleConnections.length > 0) {
+            log.info('[enable-banking] Cleaning up stale pending connections', {
+              count: staleConnections.length,
+            })
+            await supabase
+              .from('bank_connections')
+              .update({ status: 'error', error_message: 'Superseded by new connection attempt', oauth_state: null })
+              .eq('user_id', user.id)
+              .eq('bank_name', aspsp_name)
+              .eq('status', 'pending')
+          }
+
           const redirectUrl = `${process.env.NEXT_PUBLIC_APP_URL}/api/extensions/enable-banking/callback`
 
           // Generate cryptographic state token for CSRF protection