Make ASTNode#line support beginless and endless ranges

lib/yard/parser/ruby/ast_node.rb

@@ -271,7 +271,7 @@ def has_line?
 
         # @return [Fixnum] the starting line number of the node
         def line
-          line_range && line_range.first
+          line_range && (line_range.begin || line_range.end)
         end
 
         # @return [String] the first line of source represented by the node.

spec/parser/ruby/ast_node_spec.rb

@@ -30,4 +30,18 @@
                                "      source: 4..6))\n"
     end
   end unless YARD.ruby31?
+
+  describe "#line" do
+    it "does not break on beginless or endless ranges" do
+      skip "Unsupported ruby version" if Gem::Version.new(RUBY_VERSION) < Gem::Version.new('2.7')
+
+      obj = YARD::Parser::Ruby::RubyParser.parse("# x\nbye", "x").ast
+      # obj.range returns (2..2) in this case, but sometimes, this range is set
+      # to a beginless or endless one.
+      obj.line_range = Range.new(nil, 2)
+      expect(obj.line).to eq 2
+      obj.line_range = Range.new(2, nil)
+      expect(obj.line).to eq 2
+    end
+  end
 end if HAVE_RIPPER