Handle stray hyphens in Ruby parser

Author: rmosolgo

lib/graphql/language/lexer.rb

@@ -89,6 +89,8 @@ def debug_token_value(token_name)
           "..."
         elsif token_name == :STRING
           string_value
+        elsif @scanner.matched_size.nil?
+          @scanner.peek(1)
         else
           token_value
         end

lib/graphql/language/parser.rb

@@ -739,13 +739,7 @@ def expect_token_value(tok)
       # token_value works for when the scanner matched something
       # which is usually fine and it's good for it to be fast at that.
       def debug_token_value
-        if token_name && Lexer::Punctuation.const_defined?(token_name)
-          Lexer::Punctuation.const_get(token_name)
-        elsif token_name == :ELLIPSIS
-          "..."
-        else
-          @lexer.token_value
-        end
+        @lexer.debug_token_value(token_name)
       end
     end
   end

spec/graphql/language/parser_spec.rb

@@ -54,6 +54,19 @@
     assert_equal expected_msg, err.message
   end
 
+  it "handles hyphens with errors" do
+    err = assert_raises(GraphQL::ParseError) {
+      GraphQL.parse("{ field(argument:a-b) }")
+    }
+    expected_msg = if USING_C_PARSER
+      "syntax error, unexpected invalid token (\"-\") at [1, 19]"
+    else
+      "Expected NAME, actual: INT (\"-\") at [1, 19]"
+    end
+
+    assert_equal expected_msg, err.message
+  end
+
   describe "anonymous fragment extension" do
     let(:document) { GraphQL.parse(query_string) }
     let(:query_string) {%|