Use Rails native AR patterns to control the user scope

[epugh]

Description

Go back to using more native rails code for #979 .....

@reid-rigo can you give this a quick once over?

Motivation and Context

How Has This Been Tested?

Screenshots or GIFs (if appropriate):

Types of changes

• [] Bug fix (non-breaking change which fixes an issue)
• [] Improvement (non-breaking change which improves existing functionality)
• [] New feature (non-breaking change which adds new functionality)
• [] Breaking change (fix or feature that would cause existing functionality to change)

Checklist:

• [] My code follows the code style of this project.
• [] My change requires a change to the documentation.
• [] I have updated the documentation accordingly.
• [] I have read the CONTRIBUTING document.
• [] I have added tests to cover my changes.
• [] All new and existing tests passed.

[reid-rigo]

Looks good. I think adding a test case makes sense here. This one catches the issue:

it 'returns distinct cases' do
  case_ids = Case.for_user(users(:random)).pluck(:id)
  assert_equal case_ids, case_ids.uniq
end

[epugh]

Looks good. I think adding a test case makes sense here. This one catches the issue:

it 'returns distinct cases' do
  case_ids = Case.for_user(users(:random)).pluck(:id)
  assert_equal case_ids, case_ids.uniq
end

Nice simple test case! I tend to a lot of setup and verbosity that isn't actually needed!

[reid-rigo]

It looks like all of these else cases need the select, right? Since they're all looking at last_viewed_at

[epugh]

Thansk for the check, this led me to wondering who used the method and discovering that the code was added on the backend, but we never quite the front end JS to properly work... So removed the code.