[HADOOP-16847] Test TestGroupsCaching fail if HashSet iterates in a different order

• Type: Improvement
• Status: Resolved
• Priority: Minor
• Resolution: Fixed
• Affects Version/s: 3.2.1
• Fix Version/s: 3.3.0, 3.2.2
• Component/s: test
• Assignee: testfixer0
• Reporter: testfixer0
• Created: 06/Feb/20 18:46
• Updated: 11/Feb/20 11:46
• Resolved: 11/Feb/20 11:26

Description

The test `testNegativeGroupCaching` can fail if the iteration order of HashSet changes. In detail, the method `assertEquals` (line 331) compares `groups.getGroups(user)` with an ArrayList `myGroups`. The method `getGroups` converts `allGroups` (a HashSet) to a list and it calls iterator in HashSet. However, the iteration is non-deterministic.

This PR proposes to modify HashSet to LinkedHashSet for a deterministic order.

Issue Links

• links to: GitHub Pull Request #1835