Run checks

When proposing an action in a law, several validation checks are performed to ensure the action is valid and authorized. These checks are implemented in the checksAtPropose function.

Validation Process

1. Base Checks

The baseChecksAtPropose function in LawUtilities performs fundamental validations:

function baseChecksAtPropose(
    ILaw.Conditions memory conditions,
    bytes memory lawCalldata,
    address powers,
    uint256 nonce
) external view

Parent Law Completion Check

• Verifies if a parent law has been completed (if required)

• Checks the state of the parent law's action

• Reverts with LawUtilities__ParentNotCompleted if parent law is not completed

Parent Law Block Check

• Verifies if a parent law must not be completed

• Checks the state of the parent law's action

• Reverts with LawUtilities__ParentBlocksCompletion if parent law is completed

2. Custom Checks

Laws can implement additional validation logic by overriding checksAtPropose:

function checksAtPropose(
    address caller,
    Conditions memory conditions,
    bytes memory lawCalldata,
    uint256 nonce,
    address powers
) public view virtual

Common custom checks include:

• Role-based access control

• Input parameter validation

• State-dependent conditions

• Time-based restrictions

• Resource availability

Error Handling

The following errors may be thrown during proposal checks:

• LawUtilities__ParentNotCompleted: Parent law has not been completed

• LawUtilities__ParentBlocksCompletion: Parent law is completed when it shouldn't be

• LawUtilities__StringTooShort: String parameter is too short

• LawUtilities__StringTooLong: String parameter is too long

Best Practices

1. Comprehensive Validation

   • Validate all input parameters

   • Check all required conditions

   • Verify caller permissions

   • Ensure state consistency

2. Gas Optimization

   • Order checks from least to most expensive

   • Use early returns for invalid conditions

   • Cache frequently accessed values

3. Error Messages

   • Use clear and descriptive error messages

   • Include relevant context in errors

   • Follow consistent error naming

4. Security

   • Validate all external inputs

   • Check for reentrancy vulnerabilities

   • Verify caller permissions

   • Validate state transitions

Example Implementation

function checksAtPropose(
    address caller,
    Conditions memory conditions,
    bytes memory lawCalldata,
    uint256 nonce,
    address powers
) public view virtual override {
    // Run base checks
    LawUtilities.baseChecksAtPropose(conditions, lawCalldata, powers, nonce);
    
    // Custom role check
    if (!hasRequiredRole(caller, conditions.allowedRole)) {
        revert("Insufficient permissions");
    }
    
    // Custom state check
    if (!isValidState()) {
        revert("Invalid state for proposal");
    }
    
    // Custom parameter validation
    validateParameters(lawCalldata);
}