format: implement more CSS selector formatting

for IdSelector, HashToken, and PseudoClassSelector, and add test coverage.

Author: flavorjones

lib/syntax_tree/css/format.rb

@@ -47,6 +47,11 @@ def visit_ident_token(node)
         q.text(node.value)
       end
 
+      # Visit a HashToken node.
+      def visit_hash_token(node)
+        q.text(node.value)
+      end
+
       # Visit a StyleRule node.
       def visit_style_rule(node)
         q.group do
@@ -77,12 +82,24 @@ def visit_type_selector(node)
         end
       end
 
+      # Visit a Selectors::IdSelector node.
+      def visit_id_selector(node)
+        q.text("#")
+        node.value.format(q)
+      end
+
       # Visit a Selectors::ClassSelector node.
       def visit_class_selector(node)
         q.text(".")
         node.value.format(q)
       end
 
+      # Visit a Selectors::PseudoClassSelector node.
+      def visit_pseudo_class_selector(node)
+        q.text(":")
+        node.value.format(q)
+      end
+
       # Visit a Selectors::Combinator node.
       def visit_combinator(node)
         node.value.format(q)

test/selectors_test.rb

@@ -194,8 +194,32 @@ class SelectorsTest < Minitest::Spec
       end
 
       describe "formatting" do
-        it "formats complex selectors" do
-          assert_selector_format(".outer section.foo>table.bar   tr", ".outer section.foo > table.bar tr")
+        it "formats compound selector with an id selector" do
+          assert_selector_format(
+            "div#foo",
+            "div#foo",
+          )
+        end
+
+        it "formats compound selector with an pseudo-class selector" do
+          assert_selector_format(
+            "div:hover",
+            "div:hover",
+          )
+        end
+
+        it "formats compound selectors" do
+          assert_selector_format(
+            "div.flex.text-xl",
+            "div.flex.text-xl",
+          )
+        end
+
+        it "formats complex selectors with whitespace" do
+          assert_selector_format(
+            ".outer section.foo>table.bar   tr",
+            ".outer section.foo > table.bar tr",
+          )
         end
 
         private
@@ -205,7 +229,7 @@ def assert_selector_format(selectors, expected)
 
           io = StringIO.new
           selectors.each do |selector|
-            selector.format(::PrettyPrint.new(io))
+            selector.format(::PP.new(io))
             assert_equal(expected, io.string)
           end
         end