Require or revert statement must have a reason string and check that each reason string is at most N characters long SOLHINT-W1014

Require or revert statement must have a reason string and check that each reason string is at most N characters long.

Bad Practice

1. Require without reason string

   pragma solidity 0.4.4;
   
   
   contract A {
   
     function b() public {
       require(!has(role, account));
       role.bearer[account] = true;
       role.bearer[account] = true;
     }
   
   }
   

Recommended

1. Require with reason string

   pragma solidity 0.4.4;
   
   
   contract A {
   
     function b() public {
       require(!has(role, account), "Roles: account already has role");
       role.bearer[account] = true;
       role.bearer[account] = true;
     }
   
   }
   

Learn more

reason-string on Solhint's documentation.