lib/rules/space-in-parens.js
function shouldOpenerRejectSpace( left, right ) {
      if ( right.type === 'Line' ) {
        return false;
      }

      if ( !astUtils.isTokenOnSameLine( left, right ) ) {
        return false;
      }

      if ( !sourceCode.isSpaceBetweenTokens( left, right ) ) {
        return false;
      }

      if ( ALWAYS ) {
        return isOpenerException( right );
      }
      return !isOpenerException( right );
    }
function shouldOpenerRejectSpace( left, right ) {
      if ( right.type === 'Line' ) {
        return false;
      }

      if ( !astUtils.isTokenOnSameLine( left, right ) ) {
        return false;
      }

      if ( !sourceCode.isSpaceBetweenTokens( left, right ) ) {
        return false;
      }

      if ( ALWAYS ) {
        return isOpenerException( right );
      }
      return !isOpenerException( right );
    }
Determines if an opener paren should not have an existing space after it
@param {Object} left The paren token
@param {Object} right The token after it
@returns {boolean} True if the paren should reject the space