[ruby/prism] Better error message on missing hash value

https://github.com/ruby/prism/commit/b20e37e82e

prism/prism.c

@@ -17030,6 +17030,10 @@ pm_parser_err_prefix(pm_parser_t *parser, pm_diagnostic_id_t diag_id) {
             PM_PARSER_ERR_TOKEN_FORMAT(parser, parser->previous, diag_id, pm_token_type_human(parser->previous.type));
             break;
         }
+        case PM_ERR_HASH_VALUE: {
+            PM_PARSER_ERR_TOKEN_FORMAT(parser, parser->current, diag_id, pm_token_type_human(parser->current.type));
+            break;
+        }
         case PM_ERR_UNARY_RECEIVER: {
             const char *human = (parser->current.type == PM_TOKEN_EOF ? "end-of-input" : pm_token_type_human(parser->current.type));
             PM_PARSER_ERR_TOKEN_FORMAT(parser, parser->previous, diag_id, human, parser->previous.start[0]);

prism/templates/src/diagnostic.c.erb

@@ -210,7 +210,7 @@ static const pm_diagnostic_data_t diagnostic_messages[PM_DIAGNOSTIC_ID_MAX] = {
     [PM_ERR_HASH_KEY]                           = { "unexpected %s, expecting '}' or a key in the hash literal", PM_ERROR_LEVEL_SYNTAX },
     [PM_ERR_HASH_ROCKET]                        = { "expected a `=>` between the hash key and value", PM_ERROR_LEVEL_SYNTAX },
     [PM_ERR_HASH_TERM]                          = { "expected a `}` to close the hash literal", PM_ERROR_LEVEL_SYNTAX },
-    [PM_ERR_HASH_VALUE]                         = { "expected a value in the hash literal", PM_ERROR_LEVEL_SYNTAX },
+    [PM_ERR_HASH_VALUE]                         = { "unexpected %s; expected a value in the hash literal", PM_ERROR_LEVEL_SYNTAX },
     [PM_ERR_HEREDOC_IDENTIFIER]                 = { "unterminated here document identifier", PM_ERROR_LEVEL_SYNTAX },
     [PM_ERR_HEREDOC_TERM]                       = { "unterminated heredoc; can't find string \"%.*s\" anywhere before EOF", PM_ERROR_LEVEL_SYNTAX },
     [PM_ERR_INCOMPLETE_QUESTION_MARK]           = { "incomplete expression at `?`", PM_ERROR_LEVEL_SYNTAX },