Merge branch 'ability-batch-issue-checking' into 'master'

Optimize checking if a user can read multiple issues

## What does this MR do?

This optimizes various parts of the code so it can more efficiently check if a user can read a list of issues.

## Are there points in the code the reviewer needs to double check?

Yes, in particular `Ability.issues_readable_by_user` should be checked to make sure it correctly allows/restricts access to issues.

## Why was this MR needed?

Currently the general approach to checking if one can read an issue is to iterate over the issues to check and call `can?(user, :read_issue, issue)` for every issue. This is not efficient as the same work has to be done for every issue.

## What are the relevant issue numbers?

* #15607 
* #17463

See merge request !5370

1 files changed, 4 insertions, 3 deletions

diff --git a/lib/banzai/reference_parser/issue_parser.rb b/lib/banzai/reference_parser/issue_parser.rb
index f306079d833..6c20dec5734 100644
--- a/lib/banzai/reference_parser/issue_parser.rb
+++ b/lib/banzai/reference_parser/issue_parser.rb
@@ -9,10 +9,11 @@ module Banzai
 
         issues = issues_for_nodes(nodes)
 
-        nodes.select do |node|
-          issue = issue_for_node(issues, node)
+        readable_issues = Ability.
+          issues_readable_by_user(issues.values, user).to_set
 
-          issue ? can?(user, :read_issue, issue) : false
+        nodes.select do |node|
+          readable_issues.include?(issue_for_node(issues, node))
         end
       end