prPriority not working as expected

[RahulGautamSingh]

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.

37.379.1

Please tell us more about your question or problem

I created a repo with two npm paclages lodash and react. I set the prPriority of lodash package to-1 using package rule. And set the prHourlyLimit to 1.

Expected Outcome: Renovate first creates a PR for react and then for lodash.
Actual Outcome: Renovate created a PR for lodash first.

Minimal Repro: https://github.com/Rahul-renovate-testing/repro-pr-priority

Logs (if relevant)

Debug Logs

sortBranches
INPUT:  [ 'renovate/lodash-4.x', 'renovate/react-18.x' ]
{ branchName: 'renovate/react-18.x', prPriority: undefined } { branchName: 'renovate/lodash-4.x', prPriority: -1 }
OUTPUT: [ 'renovate/lodash-4.x', 'renovate/react-18.x' ]

[RahulGautamSingh]

I think we should check whether the prPriority is undefined and use zero incase it is before comparing the values.

renovate/lib/workers/repository/process/sort.ts

Lines 24 to 26 in 3bcd779

	if (a.prPriority !== b.prPriority) {
	return b.prPriority! - a.prPriority!;
	}

[RahulGautamSingh]

#29306