Add test coverage to CSS class generation (#2285)

The code that generates CSS is based on a lot of boolean conditions.
The possible combinations of these grows exponentially as we add more
conditions.

Since most of the code is conditional on a single boolean, we tested the
following:

1. All `false`
2. All `true`
3. Each individual flag set to `true`

The methods tested are:

* `StreamEntriesHelper#style_classes`
* `StreamEntriesHelper#microformats_classes`
* `StreamEntriesHelper#microformats_h_class`

app/helpers/stream_entries_helper.rb

@@ -31,9 +31,13 @@ module StreamEntriesHelper
   end
 
   def microformats_h_class(status, is_predecessor, is_successor, include_threads)
-    return 'h-cite' if is_predecessor || status.reblog || is_successor
-    return 'h-entry' unless include_threads
-    ''
+    if is_predecessor || status.reblog? || is_successor
+      'h-cite'
+    elsif include_threads
+      ''
+    else
+      'h-entry'
+    end
   end
 
   def rtl?(text)

spec/helpers/stream_entries_helper_spec.rb

@@ -15,6 +15,131 @@ RSpec.describe StreamEntriesHelper, type: :helper do
     end
   end
 
+  describe '#style_classes' do
+    it do
+      status = double(reblog?: false)
+      classes = helper.style_classes(status, false, false, false)
+
+      expect(classes).to eq 'entry'
+    end
+
+    it do
+      status = double(reblog?: true)
+      classes = helper.style_classes(status, false, false, false)
+
+      expect(classes).to eq 'entry entry-reblog'
+    end
+
+    it do
+      status = double(reblog?: false)
+      classes = helper.style_classes(status, true, false, false)
+
+      expect(classes).to eq 'entry entry-predecessor'
+    end
+
+    it do
+      status = double(reblog?: false)
+      classes = helper.style_classes(status, false, true, false)
+
+      expect(classes).to eq 'entry entry-successor'
+    end
+
+    it do
+      status = double(reblog?: false)
+      classes = helper.style_classes(status, false, false, true)
+
+      expect(classes).to eq 'entry entry-center'
+    end
+
+    it do
+      status = double(reblog?: true)
+      classes = helper.style_classes(status, true, true, true)
+
+      expect(classes).to eq 'entry entry-predecessor entry-reblog entry-successor entry-center'
+    end
+  end
+
+  describe '#microformats_classes' do
+    it do
+      status = double(reblog?: false)
+      classes = helper.microformats_classes(status, false, false)
+
+      expect(classes).to eq ''
+    end
+
+    it do
+      status = double(reblog?: false)
+      classes = helper.microformats_classes(status, true, false)
+
+      expect(classes).to eq 'p-in-reply-to'
+    end
+
+    it do
+      status = double(reblog?: false)
+      classes = helper.microformats_classes(status, false, true)
+
+      expect(classes).to eq 'p-comment'
+    end
+
+    it do
+      status = double(reblog?: true)
+      classes = helper.microformats_classes(status, true, false)
+
+      expect(classes).to eq 'p-in-reply-to p-repost-of'
+    end
+
+    it do
+      status = double(reblog?: true)
+      classes = helper.microformats_classes(status, true, true)
+
+      expect(classes).to eq 'p-in-reply-to p-repost-of p-comment'
+    end
+  end
+
+  describe '#microformats_h_class' do
+    it do
+      status = double(reblog?: false)
+      css_class = helper.microformats_h_class(status, false, false, false)
+
+      expect(css_class).to eq 'h-entry'
+    end
+
+    it do
+      status = double(reblog?: true)
+      css_class = helper.microformats_h_class(status, false, false, false)
+
+      expect(css_class).to eq 'h-cite'
+    end
+
+    it do
+      status = double(reblog?: false)
+      css_class = helper.microformats_h_class(status, true, false, false)
+
+      expect(css_class).to eq 'h-cite'
+    end
+
+    it do
+      status = double(reblog?: false)
+      css_class = helper.microformats_h_class(status, false, true, false)
+
+      expect(css_class).to eq 'h-cite'
+    end
+
+    it do
+      status = double(reblog?: false)
+      css_class = helper.microformats_h_class(status, false, false, true)
+
+      expect(css_class).to eq ''
+    end
+
+    it do
+      status = double(reblog?: true)
+      css_class = helper.microformats_h_class(status, true, true, true)
+
+      expect(css_class).to eq 'h-cite'
+    end
+  end
+  
   describe '#rtl?' do
     it 'is false if text is empty' do
       expect(helper).not_to be_rtl ''