Fix Shorthand to ignore !default/!important

Fixes sds#809

CHANGELOG.md

@@ -11,6 +11,8 @@
 * Fix `SpaceAfterComma` linter to report correct column number
 * Fix `PrivateNamingConvention` to consider functions/mixins used inside other
   functions/mixins
+* Fix `Shorthand` to not report shorthanded values with `!important` as having
+  a shorthand length not specified in `allowed_shorthands`
 
 ## 0.49.0
 

lib/scss_lint/linter/shorthand.rb

@@ -68,6 +68,8 @@ def check_script_string(prop, script_string)
     # @param node [Sass::Script::Value::String]
     # @param values [Array<String>]
     def check_shorthand(prop, node, values)
+      values = shorthand_values(values)
+
       add_lint(node, "Shorthands of length `#{values.count}` are not allowed. " \
                      "Value was `#{values.join(' ')}`") unless allowed?(values.count)
 
@@ -138,5 +140,9 @@ def allowed?(size)
       return false unless config['allowed_shorthands']
       config['allowed_shorthands'].map(&:to_i).include?(size)
     end
+
+    def shorthand_values(values)
+      values.take(4).take_while { |value| !value.to_s.start_with?('!') }
+    end
   end
 end

spec/scss_lint/linter/shorthand_spec.rb

@@ -193,6 +193,16 @@
       SCSS
 
       it { should_not report_lint }
+
+      context 'and ends with !important' do
+        let(:scss) { <<-SCSS }
+          p {
+            margin: 4px 4px 4px !important;
+          }
+        SCSS
+
+        it { should_not report_lint }
+      end
     end
 
     context 'is fine but length is not allowed' do