We've already implemented this

test/hamlit/engine/text_test.rb

@@ -56,8 +56,7 @@ describe Hamlit::Engine do
     end
 
     it 'leaves empty spaces after backslash' do
-      skip
-      expect(render_string('\       a')).to eq("       a\n")
+      assert_render('\       a', "       a\n", skip_unindent: true)
     end
 
     it 'renders spaced - properly' do

test/test_helper.rb

@@ -30,7 +30,9 @@ module RenderAssertion
     options.delete(:compatible_only)
     options.delete(:error_with)
     options = { escape_html: true, ugly: true }.merge(options)
-    haml, html = haml.unindent, html.unindent
+    unless options.delete(:skip_unindent)
+      haml, html = haml.unindent, html.unindent
+    end
     assert_equal html, render(haml, options)
   end