Allow alternative names for the CHANGELOG file.

"CHANGELOG", "NEWS", "HISTORY", and "CHANGES" are recognized as Changelog files.

Also adds relevant tests for each of these names.

Resolves #14864.

CHANGELOG

@@ -6,6 +6,7 @@ v 8.8.0 (unreleased)
   - Add 'l' shortcut to open Label dropdown on issuables and 'i' to create new issue on a project
   - Updated search UI
   - Replace Devise Async with Devise ActiveJob integration. !3902 (Connor Shea)
+  - Allow "NEWS" and "CHANGES" as alternative names for CHANGELOG. !3768 (Connor Shea)
 v 8.7.1 (unreleased)
   - Throttle the update of `project.last_activity_at` to 1 minute. !3848

app/models/repository.rb

@@ -457,7 +457,7 @@ class Repository
   def changelog
     cache.fetch(:changelog) do
       tree(:head).blobs.find do |file|
-        file.name =~ /\A(changelog|history)/i
+        file.name =~ /\A(changelog|history|changes|news)/i
       end
     end
   end

spec/models/repository_spec.rb

@@ -134,7 +134,43 @@ describe Repository, models: true do
     end
   end
-  describe '#license_blob' do
+  describe "#changelog" do
+    before do
+      repository.send(:cache).expire(:changelog)
+    end
+
+    it 'accepts changelog' do
+      expect(repository.tree).to receive(:blobs).and_return([TestBlob.new('changelog')])
+
+      expect(repository.changelog.name).to eq('changelog')
+    end
+
+    it 'accepts news instead of changelog' do
+      expect(repository.tree).to receive(:blobs).and_return([TestBlob.new('news')])
+
+      expect(repository.changelog.name).to eq('news')
+    end
+
+    it 'accepts history instead of changelog' do
+      expect(repository.tree).to receive(:blobs).and_return([TestBlob.new('history')])
+
+      expect(repository.changelog.name).to eq('history')
+    end
+
+    it 'accepts changes instead of changelog' do
+      expect(repository.tree).to receive(:blobs).and_return([TestBlob.new('changes')])
+
+      expect(repository.changelog.name).to eq('changes')
+    end
+
+    it 'is case-insensitive' do
+      expect(repository.tree).to receive(:blobs).and_return([TestBlob.new('CHANGELOG')])
+
+      expect(repository.changelog.name).to eq('CHANGELOG')
+    end
+  end
+
+  describe "#license_blob" do
     before do
       repository.send(:cache).expire(:license_blob)
       repository.remove_file(user, 'LICENSE', 'Remove LICENSE', 'master')