Add integration tests for API to change addresses watched by geth

test/contract/contracts/SLVToken.sol

@@ -0,0 +1,25 @@
+// SPDX-License-Identifier: AGPL-3.0
+pragma solidity ^0.8.0;
+
+import "@openzeppelin/contracts/token/ERC20/ERC20.sol";
+
+contract SLVToken is ERC20 {
+    uint256 private countA;
+    uint256 private countB;
+
+    constructor() ERC20("Silver", "SLV") {}
+
+    function incrementCountA() public {
+      countA = countA + 1;
+    }
+
+    function incrementCountB() public {
+      countB = countB + 1;
+    }
+
+    receive() external payable {}
+
+    function destroy() public {
+        selfdestruct(payable(msg.sender));
+    }
+}

test/contract/hardhat.config.js

@@ -17,7 +17,18 @@ task("accounts", "Prints the list of accounts", async () => {
  * @type import('hardhat/config').HardhatUserConfig
  */
 module.exports = {
-  solidity: "0.8.0",
+  solidity: {
+    version: "0.8.0",
+    settings: {
+      outputSelection: {
+        '*': {
+          '*': [
+            'abi', 'storageLayout',
+          ]
+        }
+      }
+    }
+  },
   networks: {
     local: {
       url: 'http://127.0.0.1:8545',

test/contract/src/index.js

@@ -1,6 +1,7 @@
 const fastify = require('fastify')({ logger: true });
 const hre = require("hardhat");
 
+const { getStorageSlotKey } = require('./utils');
 
 // readiness check
 fastify.get('/v1/healthz', async (req, reply) => {
@@ -63,6 +64,72 @@ fastify.get('/v1/sendEth', async (req, reply) => {
     }
 });
 
+fastify.get('/v1/deploySLVContract', async (req, reply) => {
+    const SLVToken = await hre.ethers.getContractFactory("SLVToken");
+    const token = await SLVToken.deploy();
+    const receipt = await token.deployTransaction.wait();
+
+    return {
+        address: token.address,
+        txHash: token.deployTransaction.hash,
+        blockNumber: receipt.blockNumber,
+        blockHash: receipt.blockHash,
+    }
+});
+
+fastify.get('/v1/destroySLVContract', async (req, reply) => {
+    const addr = req.query.addr;
+
+    const SLVToken = await hre.ethers.getContractFactory("SLVToken");
+    const token = SLVToken.attach(addr);
+
+    const tx = await token.destroy();
+    const receipt = await tx.wait();
+
+    return {
+        blockNumber: receipt.blockNumber,
+    }
+})
+
+fastify.get('/v1/incrementCountA', async (req, reply) => {
+    const addr = req.query.addr;
+
+    const SLVToken = await hre.ethers.getContractFactory("SLVToken");
+    const token = await SLVToken.attach(addr);
+
+    const tx = await token.incrementCountA();
+    const receipt = await tx.wait();
+
+    return {
+        blockNumber: receipt.blockNumber,
+    }
+});
+
+fastify.get('/v1/incrementCountB', async (req, reply) => {
+    const addr = req.query.addr;
+
+    const SLVToken = await hre.ethers.getContractFactory("SLVToken");
+    const token = await SLVToken.attach(addr);
+
+    const tx = await token.incrementCountB();
+    const receipt = await tx.wait();
+
+    return {
+        blockNumber: receipt.blockNumber,
+    }
+});
+
+fastify.get('/v1/getStorageKey', async (req, reply) => {
+    const contract = req.query.contract;
+    const label = req.query.label;
+
+    const key = await getStorageSlotKey(contract, label)
+
+    return {
+        key
+    }
+});
+
 async function main() {
     try {
         await fastify.listen(3000, '0.0.0.0');

test/contract/src/utils.js

@@ -0,0 +1,36 @@
+const { artifacts } = require("hardhat")
+const { utils, BigNumber } = require("ethers")
+
+
+async function getStorageLayout(contractName) {
+  const artifact = await artifacts.readArtifact(contractName);
+  const buildInfo = await artifacts.getBuildInfo(`${artifact.sourceName}:${artifact.contractName}`);
+
+  if (!buildInfo) {
+    throw new Error('storageLayout not present in compiler output.');
+  }
+
+  const output = buildInfo.output;
+  const { storageLayout } = output.contracts[artifact.sourceName][artifact.contractName];
+
+  if (!storageLayout) {
+    throw new Error('Contract hasn\'t been compiled.');
+  }
+
+  return storageLayout;
+};
+
+async function getStorageSlotKey(contractName, variableName) {
+  storageLayout = await getStorageLayout(contractName)
+
+  const { storage } = storageLayout;
+  const targetState = storage.find((state) => state.label === variableName);
+
+  // Throw if state variable could not be found in storage layout.
+  if (!targetState) {
+    throw new Error('Variable not present in storage layout.');
+  }
+
+  key = utils.hexlify(BigNumber.from(targetState.slot));
+  return key
+};