pauseUntil tested, coded, documented

[CarlosAlegreUr]

As discussed in this issue on the official OpenZeppelin repository, this PR introduces a refactor of the Pausable.sol contract to implement a pauseUntil(uint48 deadline) functionality.

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Changes

1. Pausable Contract

• Refactored to include the pauseUntil(uint48 unpauseDeadline) functionality.
  • Backwards Compatibility: The implementation ensures that the same storage slots are used, preventing conflicts between old and new data.
  • ERC6372 Compatibility: Time-based functionality has been designed with ERC6372 in mind.
  • Potential Developer Consideration:
    • Developers updating from previous Pausable versions who independently implemented both ERC6372 and Pausable (e.g., via IERC5805) might face challenges if different time measurements are needed for pausing and other features.
    • Example: A Pausable contract implementing IERC5805 might use different time units for pausing and voting.

2. New Directory Structure

• Created a new directory utils/pausability to accommodate the refactor:
  • Pausable.sol: General implementation of Pausable without a specific time measurement tool.
  • DefaultPausable.sol: A default implementation of Pausable using ERC6372 with block.timestamp as the time unit.

3. PausableMock Updates

• Updated the mock contract to support:
  • Calling the new pauseUntil(uint48 deadline) function.
  • Accessing the new internal view function _unpauseDeadline().

4. Unit Tests

• Added comprehensive unit tests to validate the new pauseUntil() functionality:
  • New test flows:
    • pause() -> pauseUntil()
    • pauseUntil() -> pause() (before and after the deadline)
    • pauseUntil() -> unpause() (before and after the deadline)
    • pauseUntil() -> pauseUntil() (before and after the previous deadline)

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[arr00]

This is now incorrect. If unpauseDeadline is 0 (or less than block.timestamp) the contract is not paused at all.