Files
dodo-contractV2/contracts/external/ERC20/TestERC20.sol
2020-11-29 17:38:13 +08:00

79 lines
2.3 KiB
Solidity

/*
Copyright 2020 DODO ZOO.
SPDX-License-Identifier: Apache-2.0
*/
pragma solidity 0.6.9;
import {SafeMath} from "../../lib/SafeMath.sol";
contract TestERC20 {
using SafeMath for uint256;
string public name;
uint8 public decimals;
string public symbol;
mapping(address => uint256) balances;
mapping(address => mapping(address => uint256)) internal allowed;
event Transfer(address indexed from, address indexed to, uint256 amount);
event Approval(address indexed owner, address indexed spender, uint256 amount);
constructor(
string memory _name,
uint8 _decimals,
string memory _symbol
) public {
name = _name;
decimals = _decimals;
symbol = _symbol;
}
function transfer(address to, uint256 amount) public returns (bool) {
require(to != address(0), "TO_ADDRESS_IS_EMPTY");
require(amount <= balances[msg.sender], "BALANCE_NOT_ENOUGH");
balances[msg.sender] = balances[msg.sender].sub(amount);
balances[to] = balances[to].add(amount);
emit Transfer(msg.sender, to, amount);
return true;
}
function balanceOf(address owner) public view returns (uint256 balance) {
return balances[owner];
}
function transferFrom(
address from,
address to,
uint256 amount
) public returns (bool) {
require(to != address(0), "TO_ADDRESS_IS_EMPTY");
require(amount <= balances[from], "BALANCE_NOT_ENOUGH");
require(amount <= allowed[from][msg.sender], "ALLOWANCE_NOT_ENOUGH");
balances[from] = balances[from].sub(amount);
balances[to] = balances[to].add(amount);
allowed[from][msg.sender] = allowed[from][msg.sender].sub(amount);
emit Transfer(from, to, amount);
return true;
}
function approve(address spender, uint256 amount) public returns (bool) {
allowed[msg.sender][spender] = amount;
emit Approval(msg.sender, spender, amount);
return true;
}
function allowance(address owner, address spender) public view returns (uint256) {
return allowed[owner][spender];
}
function mint(address account, uint256 amount) external {
balances[account] = balances[account].add(amount);
}
}