Add snapshot and revert endpoints (#32)

packages/rollup-full-node/src/app/test-web3-rpc-handler.ts

@@ -55,18 +55,24 @@ export class TestWeb3Handler extends DefaultWeb3Handler {
    * Override to add some test RPC methods.
    */
   public async handleRequest(method: string, params: any[]): Promise<string> {
-    if (method === Web3RpcMethods.increaseTimestamp) {
-      this.assertParameters(params, 1)
-      this.increaseTimestamp(params[0])
-      log.debug(`Set increased timestamp by ${params[0]} seconds.`)
-      return TestWeb3Handler.successString
+    switch (method) {
+      case Web3RpcMethods.increaseTimestamp:
+        this.assertParameters(params, 1)
+        this.increaseTimestamp(params[0])
+        log.debug(`Set increased timestamp by ${params[0]} seconds.`)
+        return TestWeb3Handler.successString
+      case Web3RpcMethods.getTimestamp:
+        this.assertParameters(params, 0)
+        return add0x(this.getTimestamp().toString(16))
+      case Web3RpcMethods.snapshot:
+        this.assertParameters(params, 0)
+        return this.snapshot()
+      case Web3RpcMethods.revert:
+        this.assertParameters(params, 1)
+        return this.revert(params[0])
+      default:
+        return super.handleRequest(method, params)
     }
-    if (method === Web3RpcMethods.getTimestamp) {
-      this.assertParameters(params, 0)
-      return add0x(this.getTimestamp().toString(16))
-    }
-
-    return super.handleRequest(method, params)
   }
 
   /**
@@ -94,4 +100,20 @@ export class TestWeb3Handler extends DefaultWeb3Handler {
       throw new UnsupportedMethodError(msg)
     }
   }
+
+  /**
+   * Takes a snapshot of the current node state.
+   * @returns The snapshot id that can be used as an parameter of the revert endpoint
+   */
+  private async snapshot(): Promise<string> {
+    return this.provider.send(Web3RpcMethods.snapshot, [])
+  }
+
+  /**
+   * Reverts state to the specified snapshot
+   * @param The snapshot id of the snapshot to restore
+   */
+  private async revert(snapShotId: string): Promise<string> {
+    return this.provider.send(Web3RpcMethods.revert, [snapShotId])
+  }
 }

packages/rollup-full-node/src/app/web3-rpc-handler.ts

@@ -63,7 +63,7 @@ export class DefaultWeb3Handler implements Web3Handler, FullnodeHandler {
   }
 
   protected constructor(
-    private readonly provider: Web3Provider,
+    protected readonly provider: Web3Provider,
     private readonly wallet: Wallet,
     private readonly executionManager: Contract
   ) {

packages/rollup-full-node/src/types/web3-rpc-handler.ts

@@ -37,6 +37,8 @@ export enum Web3RpcMethods {
   getTransactionReceipt = 'eth_getTransactionReceipt',
   networkVersion = 'net_version',
   sendRawTransaction = 'eth_sendRawTransaction',
+  snapshot = 'evm_snapshot',
+  revert = 'evm_revert',
 
   // Test methods:
   increaseTimestamp = 'evm_increaseTime',

packages/rollup-full-node/test/app/handler.spec.ts

@@ -86,4 +86,30 @@ describe('Web3Handler', () => {
       res.should.equal(storageValue)
     })
   })
+
+  describe('snapshot and revert', () => {
+    it('should  fail (snapshot and revert should only be available in the TestHandler)', async () => {
+      const httpProvider = new ethers.providers.JsonRpcProvider(baseUrl)
+      await new Promise((resolve, reject) => {
+        httpProvider.send('evm_snapshot', []).catch((error) => {
+          error.message.should.equal('Method not found')
+          resolve()
+        })
+      })
+
+      await new Promise((resolve, reject) => {
+        httpProvider.send('evm_snapshot', []).catch((error) => {
+          error.message.should.equal('Method not found')
+          resolve()
+        })
+      })
+
+      await new Promise((resolve, reject) => {
+        httpProvider.send('evm_revert', ['0x01']).catch((error) => {
+          error.message.should.equal('Method not found')
+          resolve()
+        })
+      })
+    })
+  })
 })

packages/rollup-full-node/test/app/test-handler.spec.ts

@@ -1,15 +1,25 @@
 import '../setup'
 /* External Imports */
 import { add0x, getLogger, remove0x } from '@eth-optimism/core-utils'
+import { ethers, ContractFactory } from 'ethers'
 
 /* Internal Imports */
-import { Web3RpcMethods, TestWeb3Handler } from '../../src'
+import {
+  Web3RpcMethods,
+  TestWeb3Handler,
+  FullnodeRpcServer,
+  DefaultWeb3Handler,
+} from '../../src'
+import * as SimpleStorage from '../contracts/build/SimpleStorage.json'
 
 const log = getLogger('test-web3-handler', true)
 
 const secondsSinceEopch = (): number => {
   return Math.round(Date.now() / 1000)
 }
+const host = '0.0.0.0'
+const port = 9999
+const baseUrl = `http://${host}:${port}`
 
 describe('TestHandler', () => {
   let testHandler: TestWeb3Handler
@@ -60,4 +70,55 @@ describe('TestHandler', () => {
       )
     })
   })
+
+  describe('Snapshot and revert', () => {
+    it('should revert state', async () => {
+      const testRpcServer = new FullnodeRpcServer(testHandler, host, port)
+
+      testRpcServer.listen()
+      const httpProvider = new ethers.providers.JsonRpcProvider(baseUrl)
+      const executionManagerAddress = await httpProvider.send(
+        'ovm_getExecutionManagerAddress',
+        []
+      )
+      const privateKey = '0x' + '60'.repeat(32)
+      const wallet = new ethers.Wallet(privateKey, httpProvider)
+      log.debug('Wallet address:', wallet.address)
+      const factory = new ContractFactory(
+        SimpleStorage.abi,
+        SimpleStorage.bytecode,
+        wallet
+      )
+
+      const simpleStorage = await factory.deploy()
+      const deploymentTxReceipt = await wallet.provider.getTransactionReceipt(
+        simpleStorage.deployTransaction.hash
+      )
+
+      const storageKey = '0x' + '01'.repeat(32)
+      const storageValue = '0x' + '02'.repeat(32)
+      const storageValue2 = '0x' + '03'.repeat(32)
+      // Set storage with our new storage elements
+      const networkInfo = await httpProvider.getNetwork()
+      const tx = await simpleStorage.setStorage(
+        executionManagerAddress,
+        storageKey,
+        storageValue
+      )
+      const snapShotId = await httpProvider.send('evm_snapshot', [])
+      const tx2 = await simpleStorage.setStorage(
+        executionManagerAddress,
+        storageKey,
+        storageValue2
+      )
+      const receipt = await httpProvider.getTransactionReceipt(tx.hash)
+      const receipt2 = await httpProvider.getTransactionReceipt(tx2.hash)
+      const response2 = await httpProvider.send('evm_revert', [snapShotId])
+      const res = await simpleStorage.getStorage(
+        executionManagerAddress,
+        storageKey
+      )
+      res.should.equal(storageValue)
+    })
+  })
 })