Make ASTNode#reset_line_info support beginless and endless ranges

lib/yard/parser/ruby/ast_node.rb

@@ -345,8 +345,8 @@ def reset_line_info
           elsif !children.empty?
             f = children.first
             l = children.last
-            self.line_range = Range.new(f.line_range.first, l.line_range.last)
-            self.source_range = Range.new(f.source_range.first, l.source_range.last)
+            self.line_range = Range.new(f.line_range.begin, l.line_range.end)
+            self.source_range = Range.new(f.source_range.begin, l.source_range.end)
           elsif @fallback_line || @fallback_source
             self.line_range = @fallback_line
             self.source_range = @fallback_source

spec/parser/ruby/ast_node_spec.rb

@@ -43,4 +43,22 @@
       expect(obj.line).to eq 2
     end
   end
+
+  describe "#reset_line_info" do
+    skip "Unsupported ruby version" if Gem::Version.new(RUBY_VERSION) <= Gem::Version.new('2.6')
+    it "does not break on beginless or endless ranges" do
+      obj = YARD::Parser::Ruby::RubyParser.parse("# x\ndef fn(arg); 42; end", "x").ast
+      obj = obj.first
+      expect(obj.children.size).to eq 3
+      fst = obj.children.first
+      lst = obj.children.last
+      fst.line_range = (..10)
+      fst.source_range = (..10)
+      lst.line_range = (2..)
+      lst.source_range = (2..)
+      obj.send(:reset_line_info)
+      expect(obj.line_range).to eq (nil..nil)
+      expect(obj.source_range).to eq (nil..nil)
+    end
+  end
 end if HAVE_RIPPER