Ignore inherit and transparent in VariableForProperty

These values are somewhat special and shouldn't be considered as
breaking the rules of this linter.

CHANGELOG.md

@@ -10,6 +10,7 @@
   multi-line comments, such as copyright notices
 * Fix bug where control comments could filter out lints from other files
   depending on scan order
+* Ignore `inherit` and `transparent` values in `VariableForProperty`
 
 ## 0.37.0
 

lib/scss_lint/linter/README.md

@@ -1486,6 +1486,9 @@ linters:
       - font
 ```
 
+Note that values like `inherit` and `transparent` will not be reported, as they
+are special kinds of values that convey additional meaning.
+
 Configuration Option | Description
 ---------------------|---------------------------------------------------------
 `properties`         | Array of property names to check

lib/scss_lint/linter/variable_for_property.rb

@@ -3,18 +3,28 @@ module SCSSLint
   class Linter::VariableForProperty < Linter
     include LinterRegistry
 
+    IGNORED_VALUES = %w[inherit transparent]
+
     def visit_root(_node)
       @properties = Set.new(config['properties'])
       yield if @properties.any?
     end
 
     def visit_prop(node)
       property_name = node.name.join
-      return unless @properties.include? property_name
+      return unless @properties.include?(property_name)
+      return if ignored_value?(node.value)
       return if node.children.first.is_a?(Sass::Script::Tree::Variable)
 
       add_lint(node, "Property #{property_name} should use " \
                      'a variable rather than a literal value')
     end
+
+  private
+
+    def ignored_value?(value)
+      value.respond_to?(:value) &&
+        IGNORED_VALUES.include?(value.value.to_s)
+    end
   end
 end

spec/scss_lint/linter/variable_for_property_spec.rb

@@ -87,6 +87,26 @@
 
       it { should report_lint line: 3 }
     end
+
+    context 'when property specifies `inherit`' do
+      let(:scss) { <<-SCSS }
+        p {
+          color: inherit;
+        }
+      SCSS
+
+      it { should_not report_lint }
+    end
+
+    context 'when property specifies `transparent`' do
+      let(:scss) { <<-SCSS }
+        p {
+          color: transparent;
+        }
+      SCSS
+
+      it { should_not report_lint }
+    end
   end
 
   context 'when properties are not specified' do