TestnetERC20
An implementation of ERC20 with the same interface as the Compound project’s testnet tokens (mainly DAI)
This contract can be deployed or the interface can be used to communicate with Compound’s ERC20 tokens. Note: this token should never be used to store real value since it allows permissionless minting.
constructor(string _name, string _symbol, uint8 _decimals) public
Constructs the TestnetERC20.
Parameters:
-
_name: The name which describes the new token. -
_symbol: The ticker abbreviation of the name. Ideally < 5 chars. -
_decimals: The number of decimals to define token precision.
allocateTo(address ownerAddress, uint256 value) external
Mints value tokens to the owner address.
Parameters:
-
ownerAddress: the address to mint to. -
value: the amount of tokens to mint.
decimals() → uint8 public
Returns the number of decimals used to get its user representation.
For example, if decimals equals 2, a balance of 505 tokens should
be displayed to a user as 5,05 (505 / 10 ** 2).
Tokens usually opt for a value of 18, imitating the relationship between
Ether and Wei. This is the value {ERC20} uses, unless {setupDecimals} is
called.
NOTE: This information is only used for _display purposes: it in
no way affects any of the arithmetic of the contract, including
{IERC20-balanceOf} and {IERC20-transfer}.
transfer(address recipient, uint256 amount) → bool public
See {IERC20-transfer}.
Requirements:
- recipient cannot be the zero address.
- the caller must have a balance of at least amount.
approve(address spender, uint256 amount) → bool public
See {IERC20-approve}.
Requirements:
- spender cannot be the zero address.
transferFrom(address sender, address recipient, uint256 amount) → bool public
See {IERC20-transferFrom}.
Emits an {Approval} event indicating the updated allowance. This is not
required by the EIP. See the note at the beginning of {ERC20};
Requirements:
- sender and recipient cannot be the zero address.
- sender must have a balance of at least amount.
- the caller must have allowance for sender's tokens of at least
amount.
increaseAllowance(address spender, uint256 addedValue) → bool public
Atomically increases the allowance granted to spender by the caller.
This is an alternative to {approve} that can be used as a mitigation for
problems described in {IERC20-approve}.
Emits an {Approval} event indicating the updated allowance.
Requirements:
- spender cannot be the zero address.
decreaseAllowance(address spender, uint256 subtractedValue) → bool public
Atomically decreases the allowance granted to spender by the caller.
This is an alternative to {approve} that can be used as a mitigation for
problems described in {IERC20-approve}.
Emits an {Approval} event indicating the updated allowance.
Requirements:
- spender cannot be the zero address.
- spender must have allowance for the caller of at least
subtractedValue.
_transfer(address sender, address recipient, uint256 amount) internal
Moves tokens amount from sender to recipient.
This is internal function is equivalent to {transfer}, and can be used to
e.g. implement automatic token fees, slashing mechanisms, etc.
Emits a {Transfer} event.
Requirements:
- sender cannot be the zero address.
- recipient cannot be the zero address.
- sender must have a balance of at least amount.
_mint(address account, uint256 amount) internal
Creates amount tokens and assigns them to account, increasing
the total supply.
Emits a {Transfer} event with from set to the zero address.
Requirements
- to cannot be the zero address.
_burn(address account, uint256 amount) internal
Destroys amount tokens from account, reducing the
total supply.
Emits a {Transfer} event with to set to the zero address.
Requirements
- account cannot be the zero address.
- account must have at least amount tokens.
_approve(address owner, address spender, uint256 amount) internal
Sets amount as the allowance of spender over the owner`s tokens.
This is internal function is equivalent to `approve, and can be used to
e.g. set automatic allowances for certain subsystems, etc.
Emits an {Approval} event.
Requirements:
- owner cannot be the zero address.
- spender cannot be the zero address.
setupDecimals(uint8 decimals) internal
Sets {decimals} to a value other than the default one of 18. WARNING: This function should only be called from the constructor. Most applications that interact with token contracts will not expect {decimals} to ever change, and may work incorrectly if it does.
_beforeTokenTransfer(address from, address to, uint256 amount) internal
Hook that is called before any transfer of tokens. This includes
minting and burning.
Calling conditions:
- when from and to are both non-zero, amount of from's tokens
will be to transferred to to.
- when from is zero, amount tokens will be minted for to.
- when to is zero, amount of from's tokens will be burned.
- from and to are never both zero.
To learn more about hooks, head to Using Hooks.