fromat code style and fix config file

Author: jolycao

Diff for: basic/25-multi-sig-wallet/.env.example

@@ -0,0 +1,2 @@
+PRIVATE_KEY=xxxxxxxxxxxxxxxx
+INFURA_ID=yyyyyyyy

Diff for: basic/25-multi-sig-wallet/contracts/Hello.sol

@@ -1,4 +1,4 @@
-pragma solidity ^0.6.0;
+pragma solidity ^0.6.12;
 
 contract Hello {
     uint256 public balance;

Diff for: basic/25-multi-sig-wallet/contracts/MultiSigWallet.sol

@@ -1,4 +1,4 @@
-pragma solidity ^0.6.0;
+pragma solidity ^0.6.12;
 
 
 /// @title Multisignature wallet - Allows multiple parties to agree on transactions before execution.

Diff for: basic/25-multi-sig-wallet/hardhat.config.js

@@ -1,5 +1,6 @@
 require("@nomiclabs/hardhat-waffle");
 const fs = require("fs");
+require('dotenv').config()
 
 // This is a sample Hardhat task. To learn how to create your own go to
 // https://hardhat.org/guides/create-task.html
@@ -13,9 +14,9 @@ task("accounts", "Prints the list of accounts", async () => {
 
 function mnemonic() {
 
- return fs.readFileSync("./sk.txt").toString().trim();
-
-}
+  return process.env.PRIVATE_KEY
+ 
+ }
 
 /**
  * @type import('hardhat/config').HardhatUserConfig
@@ -24,7 +25,7 @@ module.exports = {
   solidity: {
     compilers: [
       {
-        version: "0.6.0"
+        version: "0.6.12"
       },
       {
         version: "0.8.0",
@@ -46,25 +47,25 @@ module.exports = {
       */
     },
     rinkeby: {
-      url: "https://rinkeby.infura.io/v3/0aae8358bfe04803b8e75bb4755eaf07", //<---- YOUR INFURA ID! (or it won't work)
+      url: "https://rinkeby.infura.io/v3/" + process.env.INFURA_ID, //<---- YOUR INFURA ID! (or it won't work)
       accounts: [
       mnemonic()
       ],
     },
     kovan: {
-      url: "https://kovan.infura.io/v3/0aae8358bfe04803b8e75bb4755eaf07", //<---- YOUR INFURA ID! (or it won't work)
+      url: "https://kovan.infura.io/v3/" + process.env.INFURA_ID, //<---- YOUR INFURA ID! (or it won't work)
       accounts: [
         mnemonic()
       ],
     },
     mainnet: {
-      url: "https://mainnet.infura.io/v3/0aae8358bfe04803b8e75bb4755eaf07", //<---- YOUR INFURA ID! (or it won't work)
+      url: "https://mainnet.infura.io/v3/" + process.env.INFURA_ID, //<---- YOUR INFURA ID! (or it won't work)
       accounts: [
         mnemonic()
       ],
     },
     ropsten: {
-      url: "https://ropsten.infura.io/v3/0aae8358bfe04803b8e75bb4755eaf07", //<---- YOUR INFURA ID! (or it won't work)
+      url: "https://ropsten.infura.io/v3/" + process.env.INFURA_ID, //<---- YOUR INFURA ID! (or it won't work)
       accounts: [
         mnemonic()
       ],

Diff for: basic/25-multi-sig-wallet/package.json

@@ -16,5 +16,8 @@
     "ethers": "^5.3.1",
     "hardhat": "^2.4.1"
   },
-  "description": ""
+  "description": "",
+  "dependencies": {
+    "dotenv": "^10.0.0"
+  }
 }

Diff for: basic/25-multi-sig-wallet/test/test.js

@@ -51,6 +51,9 @@ describe("MultiSigWallet test",function(){
     const submitTransaction = await multiSigWallet.submitTransaction(hello.address, 0, payload);
     const transactionReceipt = await submitTransaction.wait();
     //console.log("transactionReceipt:",transactionReceipt);
+
+    // 检查结果
+    expect((await hello.balance()).toString()).to.equal("233");
 
 
     // await multiSigWallet.queryFilter("Submission" , transactionReceipt.blockNumber ,transactionReceipt.blockNumber)