"failed to add assignee (Cannot read properties of undefined (reading 'id'))" on Gitlab self-hosted

[rarkins]

Discussed in #27890

^{Originally posted by deronnax March 12, 2024}

What would you like help with?

I think I found a bug

How are you running Renovate?

Self-hosted

If you're self-hosting Renovate, tell us which platform (GitHub, GitLab, etc) and which version of Renovate.

Gitlab

Please tell us more about your question or problem

Hello.
I run renovate on one of our repo, and on this repository, renovate has an assignee problem: it fails to add assignees to an MR (see logs).
I won't be able to do a minimum reproducible use case, but maybe we can work something else.
I am pretty sure it did work when using reviewers instead of assignees.
Thank you very much.

Logs (if relevant)

Logs

DEBUG: Adding assignees 'orga/core/squad-honeytoken' to #11290 (repository=gg-code/prm/ward-runs-app, branch=renovate/python-gitlab-4.x)
DEBUG: addAssignees error (repository=gg-code/prm/ward-runs-app, branch=renovate/python-gitlab-4.x)
       "err": {
         "message": "Cannot read properties of undefined (reading 'id')",
         "stack": "TypeError: Cannot read properties of undefined (reading 'id')\n    at getUserID (/usr/local/renovate/lib/modules/platform/gitlab/http.ts:10:13)\n    at processTicksAndRejections (node:internal/process/task_queues:95:5)\n    at Proxy.addAssignees (/usr/local/renovate/lib/modules/platform/gitlab/index.ts:1196:24)\n    at addParticipants (/usr/local/renovate/lib/workers/repository/update/pr/participants.ts:61:11)\n    at ensurePr (/usr/local/renovate/lib/workers/repository/update/pr/index.ts:501:9)\n    at processBranch (/usr/local/renovate/lib/workers/repository/update/branch/index.ts:753:28)\n    at writeUpdates (/usr/local/renovate/lib/workers/repository/process/write.ts:166:17)\n    at update (/usr/local/renovate/lib/workers/repository/process/extract-update.ts:214:11)\n    at Object.renovateRepository (/usr/local/renovate/lib/workers/repository/index.ts:77:19)\n    at attributes.repository (/usr/local/renovate/lib/workers/global/index.ts:200:11)\n    at start (/usr/local/renovate/lib/workers/global/index.ts:185:7)\n    at /usr/local/renovate/lib/renovate.ts:18:22"
       }
 WARN: Failed to add assignees (repository=gg-code/prm/ward-runs-app, branch=renovate/python-gitlab-4.x)

[rarkins]

This code needs to be refactored to be defensive:

renovate/lib/modules/platform/gitlab/http.ts

Lines 7 to 10 in 5f4af40

	export async function getUserID(username: string): Promise<number> {
	return (
	await gitlabApi.getJson<{ id: number }[]>(`users?username=${username}`)
	).body[0].id;