Function: _approve(address _owner, address _spender, uint256 _amount)

This is the internal function for approving allowances for transferring tokens.

Inputs

• _owner

  • Control: Controlled by the calling function.

  • Constraints: Checked that _owner is not the zero address.

  • Impact: The account that will allow the _spender to transfer tokens.

• _spender

  • Control: Controlled by the calling function.

  • Constraints: Checked that _spender is not the zero address.

  • Impact: The account that will be allowed to transfer the owner's tokens.

• _amount

  • Control: Controlled by the calling function.

  • 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 _owner.

  Test coverage

Negative behavior

• Should not allow approving tokens on behalf of others. This should be ensured in the calling function.

  Negative test