Add spec

spec/sass/value/argument_list_spec.rb

@@ -97,6 +97,7 @@
       expect { list.assert_function }.to raise_error(Sass::ScriptError)
       expect { list.assert_map }.to raise_error(Sass::ScriptError)
       expect(list.to_map).to be_nil
+      expect { list.assert_mixin }.to raise_error(Sass::ScriptError)
       expect { list.assert_number }.to raise_error(Sass::ScriptError)
       expect { list.assert_string }.to raise_error(Sass::ScriptError)
     end

spec/sass/value/boolean_spec.rb

@@ -28,6 +28,7 @@
       expect { value.assert_function }.to raise_error(Sass::ScriptError)
       expect { value.assert_map }.to raise_error(Sass::ScriptError)
       expect(value.to_map).to be_nil
+      expect { value.assert_mixin }.to raise_error(Sass::ScriptError)
       expect { value.assert_number }.to raise_error(Sass::ScriptError)
       expect { value.assert_string }.to raise_error(Sass::ScriptError)
     end
@@ -58,6 +59,7 @@
       expect { value.assert_function }.to raise_error(Sass::ScriptError)
       expect { value.assert_map }.to raise_error(Sass::ScriptError)
       expect(value.to_map).to be_nil
+      expect { value.assert_mixin }.to raise_error(Sass::ScriptError)
       expect { value.assert_number }.to raise_error(Sass::ScriptError)
       expect { value.assert_string }.to raise_error(Sass::ScriptError)
     end

spec/sass/value/calculation_spec.rb

@@ -33,6 +33,7 @@
       expect { calculation.assert_function }.to raise_error(Sass::ScriptError)
       expect { calculation.assert_map }.to raise_error(Sass::ScriptError)
       expect(calculation.to_map).to be_nil
+      expect { calculation.assert_mixin }.to raise_error(Sass::ScriptError)
       expect { calculation.assert_number }.to raise_error(Sass::ScriptError)
       expect { calculation.assert_string }.to raise_error(Sass::ScriptError)
     end

spec/sass/value/color_spec.rb

@@ -37,6 +37,7 @@ def hwb(hue, whiteness, blackness, alpha = nil)
         expect { color.assert_function }.to raise_error(Sass::ScriptError)
         expect { color.assert_map }.to raise_error(Sass::ScriptError)
         expect(color.to_map).to be_nil
+        expect { color.assert_mixin }.to raise_error(Sass::ScriptError)
         expect { color.assert_number }.to raise_error(Sass::ScriptError)
         expect { color.assert_string }.to raise_error(Sass::ScriptError)
       end

spec/sass/value/list_spec.rb

@@ -23,6 +23,7 @@
       expect { list.assert_function }.to raise_error(Sass::ScriptError)
       expect { list.assert_map }.to raise_error(Sass::ScriptError)
       expect(list.to_map).to be_nil
+      expect { list.assert_mixin }.to raise_error(Sass::ScriptError)
       expect { list.assert_number }.to raise_error(Sass::ScriptError)
       expect { list.assert_string }.to raise_error(Sass::ScriptError)
     end

spec/sass/value/map_spec.rb

@@ -27,6 +27,7 @@
       expect { map.assert_calculation }.to raise_error(Sass::ScriptError)
       expect { map.assert_color }.to raise_error(Sass::ScriptError)
       expect { map.assert_function }.to raise_error(Sass::ScriptError)
+      expect { map.assert_mixin }.to raise_error(Sass::ScriptError)
       expect { map.assert_number }.to raise_error(Sass::ScriptError)
       expect { map.assert_string }.to raise_error(Sass::ScriptError)
     end

spec/sass/value/mixin_spec.rb

@@ -0,0 +1,37 @@
+# frozen_string_literal: true
+
+require 'spec_helper'
+
+describe Sass::Value::Mixin do
+  it 'can round-trip a mixin reference from Sass' do
+    skip 'TODO: enable after dart-sass release'
+
+    fn = double
+    allow(fn).to receive(:call) { |args|
+      expect(args.length).to eq(1)
+      expect(args[0]).to be_a(described_class)
+      args[0]
+    }
+
+    expect(
+      Sass.compile_string(
+        "
+        @use 'sass:meta';
+
+        @mixin a() {
+          a {
+            b: c;
+          }
+        }
+
+        @include meta.apply(foo(meta.get-mixin('a')));
+        ",
+        functions: {
+          'foo($arg)': fn
+        }
+      ).css
+    ).to eq("a {\n  b: c;\n}")
+
+    expect(fn).to have_received(:call)
+  end
+end

spec/sass/value/null_spec.rb

@@ -28,6 +28,7 @@
     expect { value.assert_function }.to raise_error(Sass::ScriptError)
     expect { value.assert_map }.to raise_error(Sass::ScriptError)
     expect(value.to_map).to be_nil
+    expect { value.assert_mixin }.to raise_error(Sass::ScriptError)
     expect { value.assert_number }.to raise_error(Sass::ScriptError)
     expect { value.assert_string }.to raise_error(Sass::ScriptError)
   end

spec/sass/value/number_spec.rb

@@ -38,6 +38,7 @@
           expect { number.assert_function }.to raise_error(Sass::ScriptError)
           expect { number.assert_map }.to raise_error(Sass::ScriptError)
           expect(number.to_map).to be_nil
+          expect { number.assert_mixin }.to raise_error(Sass::ScriptError)
           expect { number.assert_string }.to raise_error(Sass::ScriptError)
         end
       end

spec/sass/value/string_spec.rb

@@ -57,6 +57,7 @@
       expect { value.assert_function }.to raise_error(Sass::ScriptError)
       expect { value.assert_map }.to raise_error(Sass::ScriptError)
       expect(value.to_map).to be_nil
+      expect { value.assert_mixin }.to raise_error(Sass::ScriptError)
       expect { value.assert_number }.to raise_error(Sass::ScriptError)
     end
   end