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.

allocateTo(address _owner, uint256 value) external

Mints value tokens to the owner address.

totalSupply() → uint256 public

See IERC20.totalSupply.,@dev Returns the amount of tokens in existence.

balanceOf(address account) → uint256 public

See IERC20.balanceOf.,@dev Returns the amount of tokens owned by account.

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.,@dev Moves amount tokens from the caller’s account to recipient.

Returns a boolean value indicating whether the operation succeeded.

Emits a Transfer event.

allowance(address owner, address spender) → uint256 public

See IERC20.allowance.,@dev Returns the remaining number of tokens that spender will be allowed to spend on behalf of owner through transferFrom. This is zero by default.

This value changes when approve or transferFrom are called.

approve(address spender, uint256 value) → bool public

See IERC20.approve.

Requirements:

  • spender cannot be the zero address.,@dev Sets amount as the allowance of spender over the caller’s tokens.

Returns a boolean value indicating whether the operation succeeded.

Beware that changing an allowance with this method brings the risk that someone may use both the old and the new allowance by unfortunate transaction ordering. One possible solution to mitigate this race condition is to first reduce the spender’s allowance to 0 and set the desired value afterwards: https://github.com/ethereum/EIPs/issues/20#issuecomment-263524729

Emits an Approval event.

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 value. - the caller must have allowance for sender’s tokens of at least `amount.,@dev Moves amount tokens from sender to recipient using the allowance mechanism. amount is then deducted from the caller’s allowance.

Returns a boolean value indicating whether the operation succeeded.

Emits a Transfer event.

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 value) internal

Destoys 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 value) 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.

_burnFrom(address account, uint256 amount) internal

Destoys amount tokens from account.amount is then deducted from the caller’s allowance.

See _burn and _approve.

Transfer(address from, address to, uint256 value) event

Emitted when value tokens are moved from one account (from) to another (to).

Note that value may be zero.

Approval(address owner, address spender, uint256 value) event

Emitted when the allowance of a spender for an owner is set by a call to approve. value is the new allowance.

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