fix project_helper.rb and add couple specs to it

app/helpers/projects_helper.rb

@@ -17,11 +17,13 @@ module ProjectsHelper
   def link_to_member_avatar(author, opts = {})
     default_opts = { avatar: true, name: true, size: 16, author_class: 'author', title: ":name" }
     opts = default_opts.merge(opts)
-    classes = %w[avatar avatar-inline]
-    classes << "s#{opts[:size]}"
+
+    return unless opts[:avatar]
+
+    classes = %W[avatar avatar-inline s#{opts[:size]}]
     classes << opts[:avatar_class] if opts[:avatar_class]
 
-    image_tag(avatar_icon(author, opts[:size]), width: opts[:size], class: classes, alt: '') if opts[:avatar]
+    image_tag(avatar_icon(author, opts[:size]), width: opts[:size], class: classes, alt: '')
   end
 
   def link_to_member(project, author, opts = {}, &block)

spec/helpers/projects_helper_spec.rb

@@ -193,13 +193,25 @@ describe ProjectsHelper do
 
   describe '#link_to_member_avatar' do
     let(:user) { build_stubbed(:user) }
+    let(:expected) { double }
 
     it 'returns image tag for member avatar' do
-      allow(helper).to receive(:image_tag).with(nil, { width: 16, class: ["avatar", "avatar-inline", "s16"], alt: "" })
-      allow(helper).to receive(:avatar_icon).with(user, 16)
+      expect(helper).to receive(:avatar_icon).with(user, 16).and_return(expected)
+      expect(helper).to receive(:image_tag).with(expected, { width: 16, class: ["avatar", "avatar-inline", "s16"], alt: "" })
 
       helper.link_to_member_avatar(user)
     end
+
+    it 'returns image tag with avatar class' do
+      expect(helper).to receive(:avatar_icon).with(user, 16).and_return(expected)
+      expect(helper).to receive(:image_tag).with(expected, { width: 16, class: ["avatar", "avatar-inline", "s16", "any-avatar-class"], alt: "" })
+
+      helper.link_to_member_avatar(user, avatar_class: "any-avatar-class")
+    end
+
+    it 'returns no image tag if avatar is nil' do
+      expect(helper.link_to_member_avatar(user, avatar: nil)).to eq(nil)
+    end
   end
 
   describe '#link_to_member' do