Render guidance if we fail to fetch offences

Previously, if we received a 404 when fetching the offences for a PoP
we'd render the generic error page.

As we've identified this scenario to be caused by a missing NOMS number
for the CRN, we want to show guidance to the user in how to correct it.

This commit conditionally renders the missing NOMS guidance page if we
receive a 404 when fetching offences.

server/controllers/apply/applicationsController.test.ts

@@ -14,6 +14,7 @@ import paths from '../../paths/apply'
 import { firstPageOfApplicationJourney, getResponses } from '../../utils/applicationUtils'
 import { DateFormats } from '../../utils/dateUtils'
 import extractCallConfig from '../../utils/restUtils'
+import { SanitisedError } from '../../sanitisedError'
 
 jest.mock('../../utils/validation')
 jest.mock('../../utils/applicationUtils')
@@ -133,6 +134,20 @@ describe('applicationsController', () => {
         personService.getOffences.mockResolvedValue([offence])
       })
 
+      describe('if we fail to fetch offences', () => {
+        it('should render guidance on missing NOMS number', async () => {
+          const err = <SanitisedError>{ data: { status: 404 } }
+          personService.getOffences.mockImplementation(() => {
+            throw err
+          })
+          const requestHandler = applicationsController.new()
+
+          await requestHandler(request, response, next)
+
+          expect(response.render).toHaveBeenCalledWith('applications/people/missingNoms')
+        })
+      })
+
       describe('if an error has not been sent to the flash', () => {
         beforeEach(() => {
           ;(fetchErrorsAndUserInput as jest.Mock).mockImplementation(() => {

server/controllers/apply/applicationsController.ts

@@ -58,19 +58,28 @@ export default class ApplicationsController {
       if (crnArr.length) {
         const crn = crnArr[0]
         const person = await this.personService.findByCrn(callConfig, crn)
-        const offences = await this.personService.getOffences(callConfig, crn)
 
-        const offenceId = offences.length === 1 ? offences[0].offenceId : null
-
-        return res.render(`applications/people/confirm`, {
-          person,
-          date: DateFormats.dateObjtoUIDate(new Date()),
-          crn,
-          offenceId,
-          errors,
-          errorSummary,
-          ...userInput,
-        })
+        try {
+          const offences = await this.personService.getOffences(callConfig, crn)
+
+          const offenceId = offences.length === 1 ? offences[0].offenceId : null
+
+          return res.render(`applications/people/confirm`, {
+            person,
+            date: DateFormats.dateObjtoUIDate(new Date()),
+            crn,
+            offenceId,
+            errors,
+            errorSummary,
+            ...userInput,
+          })
+        } catch (e) {
+          if (e?.data?.status === 404) {
+            return res.render('applications/people/missingNoms')
+          }
+
+          throw e
+        }
       }
 
       return res.render('applications/new', {