test: start ad-hoc test coverage for CSS selectors

Author: flavorjones

test/selectors_test.rb

@@ -0,0 +1,76 @@
+# frozen_string_literal: true
+
+require "test_helper"
+
+module SyntaxTree
+  module CSS
+    class SelectorsTest < Minitest::Spec
+      it "parses a simple class selector" do
+        actual = parse_selectors(".flex")
+
+        assert_pattern do
+          actual => [Selectors::ClassSelector[value: { value: "flex" }]]
+        end
+      end
+
+      it "parses a compound class selector" do
+        actual = parse_selectors(".flex.text-xl")
+
+        assert_pattern do
+          actual => [
+            Selectors::CompoundSelector[
+              subclasses: [
+                Selectors::ClassSelector[value: { value: "flex" }],
+                Selectors::ClassSelector[value: { value: "text-xl" }]
+              ]
+            ]
+          ]
+        end
+      end
+
+      it "parses a compound selector" do
+        actual = parse_selectors("div.flex")
+
+        assert_pattern do
+          actual => [
+            Selectors::CompoundSelector[
+              type: { value: { name: { value: "div" } } },
+              subclasses: [Selectors::ClassSelector[value: { value: "flex" }]],
+              pseudo_elements: []
+            ]
+          ]
+        end
+      end
+
+      it "parses a compound selector with a pseudo-element" do
+        actual = parse_selectors("div.flex::first-line")
+
+        assert_pattern do
+          actual => [
+            Selectors::CompoundSelector[
+              type: { value: { name: { value: "div" } } },
+              subclasses: [Selectors::ClassSelector[value: { value: "flex" }]],
+              pseudo_elements: [
+                [
+                  Selectors::PseudoElementSelector[
+                    Selectors::PseudoClassSelector[
+                      value: { value: "first-line" }
+                    ]
+                  ],
+                  []
+                ]
+              ]
+            ]
+          ]
+        end
+      end
+
+      private
+
+      def parse_selectors(selectors)
+        css = selectors + " {}"
+        Parser.new(css).parse.rules.first.selectors
+      end
+    end
+  end
+end