Revert "Assume that AttributeParser will always be available"

This reverts commit caf213b.

We can continue using the existing method in haml 6.0.1 per
haml/haml#1085.

Author: raxod502

lib/syntax_tree/haml/format.rb

@@ -330,11 +330,15 @@ def visit_tag(node)
         if node.value[:dynamic_attributes].old
           parts << PlainPart.new("%div") if parts.empty?
 
-          dynamic = parse_attributes(node.value[:dynamic_attributes].old)
-          parts << if dynamic.is_a?(LiteralHashValue)
-            PlainPart.new(dynamic.value)
+          if ::Haml::AttributeParser.available?
+            dynamic = parse_attributes(node.value[:dynamic_attributes].old)
+            parts << if dynamic.is_a?(LiteralHashValue)
+              PlainPart.new(dynamic.value)
+            else
+              HashAttributesPart.new(dynamic)
+            end
           else
-            HashAttributesPart.new(dynamic)
+            parts << PlainPart.new(node.value[:dynamic_attributes].old)
           end
         end
 

test/tag_test.rb

@@ -121,6 +121,17 @@ def test_long_declaration_before_text
     HAML
   end
 
+  def test_long_declaration_before_text_without_parser
+    long = "a" * 80
+
+    ::Haml::AttributeParser.stub(:available?, false) do
+      assert_format("%button{ data: { current: #{long} } } foo", <<~HAML)
+        %button{ data: { current: #{long} } }
+          foo
+      HAML
+    end
+  end
+
   def test_quotes_in_strings
     assert_format("%div{title: 'escape \" quotes'}")
   end