Caveats helper library

[danfinlay]

Caveats Library: Simplified Caveat Creation for Tests

This PR introduces the Caveats library, designed to streamline the process of creating caveats for testing purposes. The library provides a set of easy-to-use functions that generate caveat structures with minimal input, prioritizing readability over gas efficiency.

Key Features

• Simplified caveat creation for various enforcer types
• Consistent interface across different caveat types
• Improved readability in test code
• Encapsulation of complex abi encoding and packing

Library Interface

The Caveats library exposes the following functions, each returning a Caveat struct:

1. createAllowedCalldataCaveat(address, uint256, bytes)
2. createERC721TransferCaveat(address, address, uint256)
3. createRedeemerCaveat(address, address[])
4. createValueLteCaveat(address, uint256)
5. createNativeAllowanceCaveat(address, uint256)
6. createTimestampCaveat(address, uint128, uint128)
7. createPasswordCaveat(address, uint256)
8. createNonceCaveat(address, uint256)
9. createIdCaveat(address, uint256)
10. createNativeBalanceGteCaveat(address, address, uint256)
11. createNativeTokenPaymentCaveat(address, address, uint256)
12. createLimitedCallsCaveat(address, uint256)
13. createAllowedMethodsCaveat(address, string[])
14. createAllowedTargetsCaveat(address, address[])
15. createArgsEqualityCheckCaveat(address, bytes)
16. createBlockNumberCaveat(address, uint128, uint128)
17. createDeployedEnforcerCaveat(address, address, bytes32, bytes)
18. createERC20BalanceGteCaveat(address, address, uint256)
19. createERC20TransferAmountCaveat(address, address, uint256)

Each function takes the enforcer address as its first parameter, followed by caveat-specific parameters. The library handles the necessary abi encoding and packing internally, returning a properly formatted Caveat struct.

Usage Example

Caveat memory timestampCaveat = Caveats.createTimestampCaveat(
    address(timestampEnforcer),
    uint128(block.timestamp),
    uint128(block.timestamp + 1 days)
);

This library significantly simplifies caveat creation in tests, improving code readability and reducing the potential for errors when manually constructing caveat structures.