Improve ColorVariable to flag uses of rgb/rgba/hsl/hsla

CHANGELOG.md

@@ -4,6 +4,7 @@
 
 * Fix `SpaceAroundOperator` linter to not report false positives operators in
   interpolation
+* Improve `ColorVariable` to flag uses of rgb/rgba/hsl/hsla
 
 ## 0.41.0
 

lib/scss_lint/linter/color_variable.rb

@@ -3,6 +3,8 @@ module SCSSLint
   class Linter::ColorVariable < Linter
     include LinterRegistry
 
+    COLOR_FUNCTIONS = %w[rgb rgba hsl hsla]
+
     def visit_script_color(node)
       return if in_variable_declaration?(node) ||
                 in_map_declaration?(node) ||
@@ -30,6 +32,14 @@ def visit_comment(_node)
       # comments, so it's easiest to just ignore them.
     end
 
+    def visit_script_funcall(node)
+      if color_function?(node) && all_arguments_are_literals?(node)
+        record_lint node, node.to_sass
+      else
+        yield
+      end
+    end
+
   private
 
     def record_lint(node, color)
@@ -63,5 +73,15 @@ def in_rgba_function_call?(node)
     def in_map_declaration?(node)
       node_ancestor(node, 2).is_a?(Sass::Script::Tree::MapLiteral)
     end
+
+    def all_arguments_are_literals?(node)
+      node.args.all? do |arg|
+        arg.is_a?(Sass::Script::Tree::Literal)
+      end
+    end
+
+    def color_function?(node)
+      COLOR_FUNCTIONS.include?(node.name)
+    end
   end
 end

spec/scss_lint/linter/color_variable_spec.rb

@@ -127,7 +127,7 @@
       }
     SCSS
 
-    it { should_not report_lint }
+    it { should report_lint line: 2 }
   end
 
   context 'when a color literal is used in a map declaration' do
@@ -164,4 +164,44 @@
 
     it { should_not report_lint }
   end
+
+  context 'when a color function containing literals is used in a property' do
+    let(:scss) { <<-SCSS }
+      p {
+        color: rgb(0, 100, 200);
+      }
+      a {
+        color: rgb(0%, 50%, 80%);
+      }
+      i {
+        color: rgba(0, 0, 0, .5);
+      }
+      span {
+        color: hsl(0, 100%, 50%);
+      }
+      .class {
+        color: hsla(0, 100%, 50%, .5);
+      }
+    SCSS
+
+    it { should report_lint line: 2 }
+    it { should report_lint line: 5 }
+    it { should report_lint line: 8 }
+    it { should report_lint line: 11 }
+    it { should report_lint line: 14 }
+  end
+
+  context 'when transforming a variable value in a function call' do
+    let(:scss) { <<-SCSS }
+      p {
+        color: rgba($red, .5);
+      }
+
+      a {
+        color: lighten($red, 5%);
+      }
+    SCSS
+
+    it { should_not report_lint }
+  end
 end