Allow less strict attribute argument parsing

The prism parser is strict about attribute arguments: it only parses as
an attribute when _all_ arguments are symbols.  rdoc 7.2's parser simply
ignored any non-symbol arguments.

As an example, the rdoc for `Net::IMAP::Config` intentionally took
advantage of the looser parsing done by rdoc 7.2. That class redefines
`attr_reader`, `attr_writer` and `attr_accessor` to add keyword
arguments for type validation/coercion and defaults:

```ruby
      # Seconds to wait until a connection is opened.
      #
      # Applied separately for establishing TCP connection and starting a TLS
      # connection.
      #
      # If the IMAP object cannot open a connection within this time,
      # it raises a Net::OpenTimeout exception.
      #
      # See Net::IMAP.new and Net::IMAP#starttls.
      #
      # The default value is +30+ seconds.
      attr_accessor :open_timeout, type: Integer, default: 30
```

rdoc 7.2 simply ignored the unknown keyword args, and parses this no
differently from `attr_accessor :open_timeout.`

Fixes #1790.

Author: nevans

lib/rdoc/parser/ruby.rb

@@ -1238,6 +1238,12 @@ def symbol_arguments(call_node)
       arguments_node.arguments.map { |arg| arg.value.to_sym }
     end
 
+    def any_symbol_arguments(call_node)
+      return unless arguments = call_node.arguments&.arguments
+      symbol_args = arguments.grep(Prism::SymbolNode)
+      symbol_args.map {|arg| arg.value.to_sym } if symbol_args.any?
+    end
+
     def visibility_method_arguments(call_node, singleton:)
       arguments_node = call_node.arguments
       return unless arguments_node
@@ -1346,8 +1352,8 @@ def _visit_call_private_constant(call_node)
 
     def _visit_call_attr_reader_writer_accessor(call_node, rw)
       return if @scanner.in_proc_block
-      names = symbol_arguments(call_node)
-      @scanner.add_attributes(names.map(&:to_s), rw, call_node.location.start_line) if names
+      return unless names = any_symbol_arguments(call_node)&.map(:to_s)
+      @scanner.add_attributes(names, rw, call_node.location.start_line)
     end
 
     class MethodSignatureVisitor < Prism::Visitor # :nodoc:

test/rdoc/parser/ruby_test.rb

@@ -1617,13 +1617,41 @@ class Foo
   def test_undocumentable_attributes
     util_parser <<~RUBY
       class Foo
-        attr
-        attr 42, :foo
+        # attrs
+        attr :attr1, *ignored1, :attr2, (ignored2), kwarg: :ignored3
+        # readers
+        attr_reader ignored3, :reader1, ignored4, :reader2, kw: ignored5
+        # writers
+        attr_writer :writer1, *%i[ignored6], :writer2, kwarg: :ignored7
+        # accessors
+        attr_accessor ignored8, :accessor1, (:ignored9), :accessor2, kw: :ignored10
+        # ignored
+        attr          ignored11
+        attr_reader   ignored12
+        attr_writer   ignored13
+        attr_accessor ignored14
       end
     RUBY
     klass = @store.find_class_named 'Foo'
-    assert_empty klass.method_list
-    assert_empty klass.attributes
+    assert_equal 8, klass.attributes.size
+    a1, a2, r1, r2, w1, w2, rw1, rw2 = klass.attributes
+    assert_equal ['attr1', 'attr2'], [a1.name, a2.name]
+    assert_equal ['reader1', 'reader2'], [r1.name, r2.name]
+    assert_equal ['writer1', 'writer2'], [w1.name, w2.name]
+    assert_equal ['accessor1', 'accessor2'], [rw1.name, rw2.name]
+    assert_equal ['R', 'R'], [a1.rw, a2.rw]
+    assert_equal ['R', 'R'], [r1.rw, r2.rw]
+    assert_equal ['W', 'W'], [w1.rw, w2.rw]
+    assert_equal ['RW', 'RW'], [rw1.rw, rw2.rw]
+    assert_equal ['attrs', 'attrs'], [a1.comment.text, a2.comment.text]
+    assert_equal ['readers', 'readers'], [r1.comment.text, r2.comment.text]
+    assert_equal ['writers', 'writers'], [w1.comment.text, w2.comment.text]
+    assert_equal ['accessors', 'accessors'], [rw1.comment.text, rw2.comment.text]
+    assert_equal [3, 3], [a1.line, a2.line]
+    assert_equal [5, 5], [r1.line, r2.line]
+    assert_equal [7, 7], [w1.line, w2.line]
+    assert_equal [9, 9], [rw1.line, rw2.line]
+    assert_equal [@top_level] * 8, [a1, a2, r1, r2, w1, w2, rw1, rw2].map(&:file)
   end
 
   def test_singleton_class_attributes