func ComputeIssueUpdates()

in tools/issue-labeler/labeler/backfill.go [107:166]
45 lines of code
14 McCabe index (conditional complexity)

func ComputeIssueUpdates(issues []*github.Issue, regexpLabels []RegexpLabel) []IssueUpdate {
	var issueUpdates []IssueUpdate

	for _, issue := range issues {
		// Skip pull requests
		if issue.IsPullRequest() {
			continue
		}

		desired := make(map[string]struct{})
		for _, existing := range issue.Labels {
			desired[*existing.Name] = struct{}{}
		}

		_, terraform := desired["service/terraform"]
		_, linked := desired["forward/linked"]
		_, exempt := desired["forward/exempt"]
		_, testfailure := desired["test-failure"]
		if terraform || exempt {
			continue
		}

		// Decision was made to no longer add new service labels to linked tickets, because it is
		// more difficult to know which teams have received those tickets and which haven't.
		// Forwarding a ticket to a different service team should involve removing the old service
		// label and `linked` label.
		if linked {
			continue
		}

		var issueUpdate IssueUpdate
		for label := range desired {
			issueUpdate.OldLabels = append(issueUpdate.OldLabels, label)
		}
		sort.Strings(issueUpdate.OldLabels)

		affectedResources := ExtractAffectedResources(issue.GetBody())
		for _, needed := range ComputeLabels(affectedResources, regexpLabels) {
			desired[needed] = struct{}{}
		}

		if len(desired) > len(issueUpdate.OldLabels) {
			// Forwarding test failure ticket directly
			if !linked && !testfailure {
				issueUpdate.Labels = append(issueUpdate.Labels, "forward/review")
			}
			for label := range desired {
				issueUpdate.Labels = append(issueUpdate.Labels, label)
			}
			sort.Strings(issueUpdate.Labels)

			issueUpdate.Number = issue.GetNumber()
			if issueUpdate.Number > 0 {
				issueUpdates = append(issueUpdates, issueUpdate)
			}
		}
	}

	return issueUpdates
}