Function: approve(address _spender, uint256 _amount)

Allows approving allowances for transferring tokens.

Inputs

• _spender

  • Control: Fully controlled by the caller.

  • Constraints: None.

  • Impact: The account that will be allowed to transfer tokens.

• _amount

  • Control: Fully controlled by the caller.

  • Constraints: None.

  • Impact: The amount of tokens to be allowed to be transferred.

Branches and code coverage (including function calls)

Intended branches

• Sets the allowance of _spender to _amount for the msg.sender.

  Test coverage

• Check that _spender and _owner are not the zero address (in _approve).

  Test coverage

Negative behavior

• Should not allow approving tokens on behalf of others.

  Negative test