fix: FORMS-904 user insert race condition

[WalterMoar]

Description

Users are reporting that they are occasionally receiving errors with the app. I think it would be best to fix existing errors in the application so that we can rule them out as being the cause of the problem.

When a user (IDIR or BCeID) logs in for the first time, the app is trying to create the “User” object twice. The second create will fail with a database exception, and this seems to have a cascading effect on the connection pool that causes other requests to fail (?).

ERROR: duplicate key value violates unique constraint "user_keycloakid_unique"
DETAIL: Key ("keycloakId")=(aaaaaaaa-aaaa-aaaa-aaaa-aaaaaaaaaaaa) already exists.
UniqueViolationError: insert into "user" ("createdAt", "email", "firstName", "fullName", "id", "idpCode", "idpUserId", "keycloakId", "username") values ($1, $2, $3, $4, $5, $6, $7, $8, $9) returning "id" - duplicate key value violates unique constraint "user_keycloakid_unique"
    at wrapError (/opt/app-root/src/app/node_modules/db-errors/lib/dbErrors.js:19:14)
    at handleExecuteError (/opt/app-root/src/app/node_modules/objection/lib/queryBuilder/QueryBuilder.js:1123:32)
    at QueryBuilder.execute (/opt/app-root/src/app/node_modules/objection/lib/queryBuilder/QueryBuilder.js:449:20)
    at processTicksAndRejections (node:internal/process/task_queues:96:5)
    at async Object.createUser (/opt/app-root/src/app/src/forms/auth/service.js:26:7)
    at async Object.getUserId (/opt/app-root/src/app/src/forms/auth/service.js:121:14)
    at async Object.login (/opt/app-root/src/app/src/forms/auth/service.js:207:18)
    at async setUser (/opt/app-root/src/app/src/forms/auth/middleware/userAccess.js:25:23)

When this happens the timestamp on the error log is very soon after the “createdAt” timestamp that’s in the table.

Reproduce: create a BCeID form and a BCeID user. Make sure the user is not in the DB, if it is then delete it. Using a new incognito window go to the form link and log in. The network failures are for: rbac/current and forms/guid/options.

Looks like a race condition in app/src/forms/auth/service.js between getting the user and creating it:

    // if this user does not exists, add...
    let user = await User.query().first().where('idpUserId', obj.idpUserId);

    if (!user) {
      // add to the system.
      user = await service.createUser(obj);
    }

Types of changes

Bug fix (non-breaking change which fixes an issue)

Checklist

• I have read the CONTRIBUTING doc
• I have checked that unit tests pass locally with my changes
• I have run the npm script lint on the frontend and backend
• I have added tests that prove my fix is effective or that my feature works
• I have added necessary documentation (if appropriate)
• I have approval from the product owner for the contribution in this pull request

Further comments

• I marked some methods of the service with an underscore prefix to indicate that they are "private" within the class.
• They key to the fix was to ignore the exceptions based on the keycloakId constraint, and to fetch using the keycloakId and not the user table's id. This way if you have two inserts at the same time, then the second one will fail to insert but still retrieve the correct user.