Merge branch 'fix-already-selected-activity-link' into 'master'

Fix inconsistent highlighting of already selected activity nav-links

## What does this MR do?

*  Remove edge case where user could deselect an activity nav-link (which seems to be returning all the events)
*  Explicitly add an `All` tab to return all the events

## Are there points in the code the reviewer needs to double check?
Shouldn't be

## Why was this MR needed?
Resolves existing UI inconsistency

## Screenshots (if relevant)
Before:
![4OzkoQVJYc](/uploads/fd2a7fdbde2159e875482ec7b828fe60/4OzkoQVJYc.gif)

After:
![E0lj8UhEUU](/uploads/7eb5155861eb79d72957de04c9f172c9/E0lj8UhEUU.gif)

## Does this MR meet the acceptance criteria?

- [x] [CHANGELOG](https://gitlab.com/gitlab-org/gitlab-ce/blob/master/CHANGELOG) entry added
- Tests
  - [x] All builds are passing
- [x] Conform by the [style guides](https://gitlab.com/gitlab-org/gitlab-ce/blob/master/CONTRIBUTING.md#style-guides)
- [x] Branch has no merge conflicts with `master` (if you do - rebase it please)
- [x] [Squashed related commits together](https://git-scm.com/book/en/Git-Tools-Rewriting-History#Squashing-Commits)

## What are the relevant issue numbers?

*  Closes #21631
*  Closes #21452


See merge request !6091

1 files changed, 13 insertions, 10 deletions

diff --git a/lib/event_filter.rb b/lib/event_filter.rb
index 668d2fa41b3..96e70e37e8f 100644
--- a/lib/event_filter.rb
+++ b/lib/event_filter.rb
@@ -2,8 +2,8 @@ class EventFilter
   attr_accessor :params
 
   class << self
-    def default_filter
-      %w{ push issues merge_requests team}
+    def all
+      'all'
     end
 
     def push
@@ -35,18 +35,21 @@ class EventFilter
     return events unless params.present?
 
     filter = params.dup
-
     actions = []
-    actions << Event::PUSHED if filter.include? 'push'
-    actions << Event::MERGED if filter.include? 'merged'
 
-    if filter.include? 'team'
-      actions << Event::JOINED
-      actions << Event::LEFT
+    case filter
+    when EventFilter.push
+      actions = [Event::PUSHED]
+    when EventFilter.merged
+      actions = [Event::MERGED]
+    when EventFilter.comments
+      actions = [Event::COMMENTED]
+    when EventFilter.team
+      actions = [Event::JOINED, Event::LEFT]
+    when EventFilter.all
+      actions = [Event::PUSHED, Event::MERGED, Event::COMMENTED, Event::JOINED, Event::LEFT]
     end
 
-    actions << Event::COMMENTED if filter.include? 'comments'
-
     events.where(action: actions)
   end