fix readme && test code for task 14

Author: longdacao

basic/14-chainlink-price-feed/.env.example

@@ -1,3 +1,4 @@
 PRIVATE_KEY=xxxxxxxxxxxxxxxx
 INFURA_ID=yyyyyyyy
-RandomNumberConsumer_ADDRESS=cccccccc
+RandomNumberConsumer_ADDRESS=cccccccc
+SubscriptionId=ddddd

basic/14-chainlink-price-feed/README.md

@@ -1,4 +1,4 @@
-# 喂价预言机
+# 喂价 和 随机数 预言机
 
 区块链是非常安全可靠的价值交换网络，但却无法安全防篡改地获取链下数据或将数据发送至链下系统。使用 Chainlink 预言机喂价, 通过预言机网络在链上直接获取实时金融市场价格数据
 
@@ -73,29 +73,66 @@ Chainlink VRF 可验证随机函数， 是一种可证明公平且可验证的
 
 ### 操作流程
 
-1. 在 kovan 测试网络环境下，将 Link token (测试代币)添加到小狐狸钱包，初始会自动发放 10 个测试代币，token address：
-   `0xa36085F69e2889c224210F603D836748e7dC0088`
-2. 运行部署脚本部署合约
+1. 创建 ChainLink SubscriptionID  
+登陆 [ChainLink VRF 测试网](https://vrf.chain.link/?_ga=2.225785050.1950508783.1645630272-1230768383.1643005305) , 点击 "Create Subscription" 创建 SubscriptionID , 之后可以在 "My Subscriptions" 中看到创建的 SubscriptionID
+<center><img src="https://github.com/Dapp-Learning-DAO/Dapp-Learning-Arsenal/blob/main/images/basic/14-chainlink-price-feed/ChainLinkVRF.png?raw=true" /></center> 
+
+
+2. 保存 SubscriptionID  
+将上一步创建的 SubscriptionID 保存到 .env 文件中 
+<center><img src="https://github.com/Dapp-Learning-DAO/Dapp-Learning-Arsenal/blob/main/images/basic/14-chainlink-price-feed/SubscriptionID.png?raw=true" /></center>
+
+```sh
+## .env
+SubscriptionId=ddddd
+```
+
+3. 运行部署脚本部署合约
 
    ```sh
-   npx hardhat run scripts/02-RandomNumberConsumerDeploy.js --network kovan
+   npx hardhat run scripts/02-RandomNumberConsumerDeploy.js --network rinkeby
    ```
 
-3. 使用小狐狸向合约转账 Link token 作为调用随机函数的费用。在 kovan 网络下，合约每次调用随机函数花费 0.1Link，转账适量即可。
 4. 将打印出来的合约部署地址，添加到 .env 文件中，运行测试脚本
 
    ```js
    // .env
    RandomNumberConsumer_ADDRESS=xxxx; // <--- you need fill this
    ```
 
-   运行测试脚本
+5. 获取 ChainLink 币  
+登陆 [ChainLink Faucet](https://faucets.chain.link/) , 在, 获取 ChainLink 币用于后续的 RandomNumberConsume , 其中 Network 选择 rinkeby, "Testnet account address" 输入合约 owner 的账户地址
+<center><img src="https://github.com/Dapp-Learning-DAO/Dapp-Learning-Arsenal/blob/main/images/basic/14-chainlink-price-feed/ChainLinkFaucet.png?raw=true" /></center>   
+
+
+6. 赋权合约消费 ChainLink 币以进行随机数获取    
+登陆 [ChainLink VRF 测试网](https://vrf.chain.link/?_ga=2.225785050.1950508783.1645630272-1230768383.1643005305) , 点击其中的 SubscriptionID 
+<center><img src="https://github.com/Dapp-Learning-DAO/Dapp-Learning-Arsenal/blob/main/images/basic/14-chainlink-price-feed/ClickSubscriptionID.png?raw=true" /></center>  
+
+
+之后在新出现的页面中, 进行 "Add Funds" 和 "Add consumer". 其中 "Add Funds" 为存入 ChainLink 币的数量, "Add consumer" 需要填入部署成功的 RandomNumberConsumer 合约地址, 即为 .env 文件中 RandomNumberConsumer_ADDRESS 的值 
+<center><img src="https://github.com/Dapp-Learning-DAO/Dapp-Learning-Arsenal/blob/main/images/basic/14-chainlink-price-feed/AddFundsAddCustomer.png?raw=true" /></center>   
+
+
+6. 运行测试脚本  
 
    ```sh
-   npx hardhat test ./test/RandomNumberConsumer.test.js --network kovan
+   npx hardhat run  scripts/03-RandomNumberConsumer --network rinkeby
    ```
 
-   结果可能需要等待 2 到 3 分钟，可以看到两次获取的随机数值不同
+   结果可能需要等待 2 到 3 分钟，可以看到 ChainLink 返回的两个随机值
+
+   ```sh
+   ❯ npx hardhat run scripts/03-RandomNumberConsumer.js --network rinkeby
+   Listen on random number call...
+   Listen on random number result...
+   first transaction hash: 0xb822b742836e3e028102b938ff9b52f5c31ecbf00a663b4865c50f83d141c441
+   event RequestId(address,uint256)
+   random0 requestID:  BigNumber { value: "68813323376039607636454911576409413136200025762802867082556497319163019860937" }
+   event FulfillRandomness(uint256,uint256[])
+   args[0] : BigNumber { value: "68813323376039607636454911576409413136200025762802867082556497319163019860937" }
+   random0Res:  21345191237588857524675400331731955708910062406377169110385405370996391926856,49611358654743768743671276783545638722996121599596073254340228099561828202433
+   ```
 
 ## todo
 

basic/14-chainlink-price-feed/contracts/RandomNumberConsumer.sol

@@ -1,66 +1,77 @@
 // SPDX-License-Identifier: MIT
+// An example of a consumer contract that relies on a subscription for funding.
 pragma solidity ^0.8.7;
 
-import "@chainlink/contracts/src/v0.8/VRFConsumerBase.sol";
+import '@chainlink/contracts/src/v0.8/interfaces/LinkTokenInterface.sol';
+import '@chainlink/contracts/src/v0.8/interfaces/VRFCoordinatorV2Interface.sol';
+import '@chainlink/contracts/src/v0.8/VRFConsumerBaseV2.sol';
 
-/**
- * THIS IS AN EXAMPLE CONTRACT WHICH USES HARDCODED VALUES FOR CLARITY.
- * PLEASE DO NOT USE THIS CODE IN PRODUCTION.
- */
+contract RandomNumberConsumer is VRFConsumerBaseV2 {
+    event FulfillRandomness(uint256,uint256[]);
+    event RequestId(address,uint256);
 
-/**
- * Request testnet LINK and ETH here: https://faucets.chain.link/
- * Find information on LINK Token Contracts and get the latest ETH and LINK faucets here: https://docs.chain.link/docs/link-token-contracts/
- */
- 
-contract RandomNumberConsumer is VRFConsumerBase {
-    
-    bytes32 internal keyHash;
-    uint256 internal fee;
-    
-    uint256 public randomResult;
+    VRFCoordinatorV2Interface COORDINATOR;
+    LinkTokenInterface LINKTOKEN;
 
-    event RequestId(address, bytes32);
-    event FulfillRandomness(bytes32, uint256);
+    // Your subscription ID.
+    uint64 s_subscriptionId;
 
-    /**
-     * Constructor inherits VRFConsumerBase
-     * 
-     * Network: Kovan
-     * Chainlink VRF Coordinator address: 0xdD3782915140c8f3b190B5D67eAc6dc5760C46E9
-     * LINK token address:                0xa36085F69e2889c224210F603D836748e7dC0088
-     * Key Hash: 0x6c3699283bda56ad74f6b855546325b68d482e983852a7a82979cc4807b641f4
-     */
-    constructor() 
-        VRFConsumerBase(
-            0xdD3782915140c8f3b190B5D67eAc6dc5760C46E9, // VRF Coordinator
-            0xa36085F69e2889c224210F603D836748e7dC0088  // LINK Token
-        )
-    {
-        // KeyHash see this link: https://docs.chain.link/docs/vrf-contracts/
-        keyHash = 0x6c3699283bda56ad74f6b855546325b68d482e983852a7a82979cc4807b641f4;
-        fee = 0.1 * 10 ** 18; // 0.1 LINK (Varies by network)
+    // Rinkeby coordinator. For other networks,
+    // see https://docs.chain.link/docs/vrf-contracts/#configurations
+    address vrfCoordinator = 0x6168499c0cFfCaCD319c818142124B7A15E857ab;
+
+    // Rinkeby LINK token contract. For other networks,
+    // see https://docs.chain.link/docs/vrf-contracts/#configurations
+    address link = 0x01BE23585060835E02B77ef475b0Cc51aA1e0709;
+
+    // The gas lane to use, which specifies the maximum gas price to bump to.
+    // For a list of available gas lanes on each network,
+    // see https://docs.chain.link/docs/vrf-contracts/#configurations
+    bytes32 keyHash = 0xd89b2bf150e3b9e13446986e571fb9cab24b13cea0a43ea20a6049a85cc807cc;
+
+    // Depends on the number of requested values that you want sent to the
+    // fulfillRandomWords() function. Storing each word costs about 20,000 gas,
+    // so 100,000 is a safe default for this example contract. Test and adjust
+    // this limit based on the network that you select, the size of the request,
+    // and the processing of the callback request in the fulfillRandomWords()
+    // function.
+    uint32 callbackGasLimit = 100000;
+
+    // The default is 3, but you can set this higher.
+    uint16 requestConfirmations = 3;
+
+    // For this example, retrieve 2 random values in one request.
+    // Cannot exceed VRFCoordinatorV2.MAX_NUM_WORDS.
+    uint32 numWords = 2;
+
+    uint256[] public s_randomWords;
+    uint256 public s_requestId;
+    address s_owner;
+
+    constructor(uint64 subscriptionId) VRFConsumerBaseV2(vrfCoordinator) {
+        COORDINATOR = VRFCoordinatorV2Interface(vrfCoordinator);
+        LINKTOKEN = LinkTokenInterface(link);
+        s_owner = msg.sender;
+        s_subscriptionId = subscriptionId;
     }
-    
-    /** 
-     * Requests randomness 
-     */
-    function getRandomNumber() public returns (bytes32 requestId) {
-        require(LINK.balanceOf(address(this)) >= fee, "Not enough LINK - fill contract with faucet");
-        requestId = requestRandomness(keyHash, fee);
-        emit RequestId(msg.sender, requestId);
-        return requestId;
+
+    // Assumes the subscription is funded sufficiently.
+    function requestRandomWords() external onlyOwner {
+        // Will revert if subscription is not set and funded.
+        s_requestId = COORDINATOR.requestRandomWords(keyHash, s_subscriptionId, requestConfirmations, callbackGasLimit, numWords);
+        emit RequestId(msg.sender,s_requestId);
     }
 
-    /**
-     * Callback function used by VRF Coordinator
-     */
-    function fulfillRandomness(bytes32 requestId, uint256 randomness) internal override {
-        randomResult = randomness;
-        emit FulfillRandomness(requestId, randomness);
-        // If your fulfillRandomness function uses more than 200k gas, the transaction will fail.
-        // do something you want, like mint NFT...
+    function fulfillRandomWords(
+        uint256, /* requestId */
+        uint256[] memory randomWords
+    ) internal override {
+        s_randomWords = randomWords;
+        emit FulfillRandomness(s_requestId,s_randomWords);
     }
 
-    // function withdrawLink() external {} - Implement a withdraw function to avoid locking your LINK in the contract
+    modifier onlyOwner() {
+        require(msg.sender == s_owner);
+        _;
+    }
 }

basic/14-chainlink-price-feed/hardhat.config.js

@@ -2,6 +2,7 @@ require("@nomiclabs/hardhat-waffle")
 require("@nomiclabs/hardhat-ethers")
 require("@nomiclabs/hardhat-web3")
 require("@nomiclabs/hardhat-truffle5")
+require("@nomiclabs/hardhat-etherscan");
 require("hardhat-deploy")
 const fs = require("fs");
 require('dotenv').config()
@@ -28,8 +29,6 @@ function mnemonic() {
 /**
  * @type import('hardhat/config').HardhatUserConfig
  */
-const kovanRpcUrl = "https://kovan.infura.io/v3/" + process.env.INFURA_ID
-const privateKey = mnemonic()
 
 module.exports = {
   defaultNetwork: "hardhat",
@@ -41,10 +40,13 @@ module.exports = {
       // }
     },
     kovan: {
-      url: kovanRpcUrl,
-      accounts: [privateKey],
-      saveDeployments: true
-    }
+      url: 'https://kovan.infura.io/v3/' + process.env.INFURA_ID, //<---- YOUR INFURA ID! (or it won't work)
+      accounts: [mnemonic()],
+    },
+    rinkeby: {
+      url: 'https://rinkeby.infura.io/v3/' + process.env.INFURA_ID, //<---- YOUR INFURA ID! (or it won't work)
+      accounts: [mnemonic()],
+    },
   },
   namedAccounts: {
     deployer: {
@@ -62,8 +64,11 @@ module.exports = {
       }
     ]
   },
+  etherscan: {
+    apiKey: "HT789QWQ9RXQQ86K3HP4EAVTEWYVKKPPJ9"
+  },
   mocha: {
-    timeout: 600000
+    timeout: 6000000000000000
   }
 }
 

basic/14-chainlink-price-feed/package.json

@@ -10,7 +10,6 @@
   "author": "",
   "license": "ISC",
   "devDependencies": {
-    "@chainlink/contracts": "0.3.0",
     "@nomiclabs/hardhat-ethers": "^2.0.2",
     "@nomiclabs/hardhat-truffle5": "^2.0.0",
     "@nomiclabs/hardhat-waffle": "^2.0.1",
@@ -23,6 +22,8 @@
     "web3": "^1.3.6"
   },
   "dependencies": {
+    "@chainlink/contracts": "^0.4.0",
+    "@nomiclabs/hardhat-etherscan": "^3.0.1",
     "dotenv": "^10.0.0"
   }
 }

basic/14-chainlink-price-feed/scripts/02-RandomNumberConsumerDeploy.js

@@ -1,5 +1,6 @@
 const hre = require('hardhat');
 require('@nomiclabs/hardhat-web3');
+require('dotenv').config();
 
 async function main() {
   const [deployer] = await ethers.getSigners();
@@ -8,7 +9,7 @@ async function main() {
 
   // 部署 RandomNumberConsumer 合约
   const RandomNumberConsumer = await ethers.getContractFactory('RandomNumberConsumer');
-  const instance = await RandomNumberConsumer.deploy();
+  const instance = await RandomNumberConsumer.deploy(process.env.SubscriptionId);
   await instance.deployed();
 
   console.log('----------------------------------------------------');

basic/14-chainlink-price-feed/scripts/03-RandomNumberConsumer.js

@@ -0,0 +1,85 @@
+const hre = require('hardhat');
+require('@nomiclabs/hardhat-web3');
+const { BigNumber } = require('ethers');
+require('dotenv').config();
+
+async function main() {
+  const provider = new ethers.providers.WebSocketProvider(`wss://rinkeby.infura.io/ws/v3/${process.env.INFURA_ID}`);
+  const { abi: RandomNumberConsumerABI } = require('../artifacts/contracts/RandomNumberConsumer.sol/RandomNumberConsumer.json');
+
+  const addr = process.env.RandomNumberConsumer_ADDRESS; // <--- you need fill it in .env file
+  if (!addr) {
+    console.log('Please set the contract address in .env file.');
+    return;
+  }
+
+  let randomNumberConsumer, user1, iface;
+
+  randomNumberConsumer = new ethers.Contract(addr, RandomNumberConsumerABI, provider);
+  iface = new ethers.utils.Interface(RandomNumberConsumerABI);
+  [user1] = await ethers.getSigners();
+
+  let random0ID, random0Res;
+
+    // 监听randomNumberConsumer 的请求随机数事件
+    const filterCall = {
+      address: addr,
+      topics: [ethers.utils.id('RequestId(address,uint256)')],
+    };
+    // 监听chainlink VRF Coordinator 的随机数回写事件
+    const filterRes = {
+      address: addr,
+      topics: [ethers.utils.id('FulfillRandomness(uint256,uint256[])')],
+    };
+
+    console.log(`Listen on random number call...`);
+    provider.on(filterCall, (log, event) => {
+      console.log('event RequestId(address,uint256)');
+      const { args } = iface.parseLog(log);
+      if (args[0] === user1.address) {
+        random0ID = args[1];
+        console.log('random0 requestID: ', random0ID);
+      } else {
+        console.log('msg.sender not matched.');
+      }
+    });
+
+    console.log(`Listen on random number result...`);
+    provider.on(filterRes, (log, event) => {
+      console.log('event FulfillRandomness(uint256,uint256[])');
+      const { args } = iface.parseLog(log);
+      console.log("args[0] :",args[0]);
+      if (BigNumber.from(args[0]).eq(random0ID)) {
+        random0Res = args[1];
+        console.log('random0Res: ', random0Res.toString());
+      } else {
+        console.log('requestID not matched.');
+      }
+    });
+
+    const tx0 = await randomNumberConsumer.connect(user1).requestRandomWords({
+      // for sometimes , it will be fail if not specify the gasLimit
+      gasLimit: 200000
+    });
+    console.log('first transaction hash:', tx0.hash);
+
+    // wait for the result event
+    for (let i = 0; i < 500; i++) {
+      if (random0Res) break;
+      console.log("Please be patient, it will take sometime to get the result")
+      await new Promise((resolve) => {
+        setTimeout(() => {
+          resolve();
+        }, 1000);
+      });
+    }
+}
+
+// We recommend this pattern to be able to use async/await everywhere
+// and properly handle errors.
+main()
+  .then(() => process.exit(0))
+  .catch((error) => {
+    console.error(error);
+    process.exit(1);
+  });