From dda6d41c98dc432ed095adcaca87c8268f9240f0 Mon Sep 17 00:00:00 2001
From: harkamal <gajinder@g11.in>
Date: Tue, 5 Sep 2023 18:39:25 +0530
Subject: [PATCH 1/8] client: some skeleton improvements from observations on
 devnet syncs

---
 packages/client/src/sync/skeleton.ts | 45 +++++++++++++++++++++-------
 1 file changed, 34 insertions(+), 11 deletions(-)

diff --git a/packages/client/src/sync/skeleton.ts b/packages/client/src/sync/skeleton.ts
index b30caf9cff..b68739184d 100644
--- a/packages/client/src/sync/skeleton.ts
+++ b/packages/client/src/sync/skeleton.ts
@@ -324,13 +324,17 @@ export class Skeleton extends MetaDBManager {
       )
       const reorg = await this.processNewHead(head, force)
       if (force && reorg) {
-        // It could just be a reorg at this head with previous tail preserved
+        // It could just be a reorg at this head with previous tail preserved unless
+        //   1. parent is not present in skeleton (it could be in chain for whatever reason) or
+        //   2. the parent < current skeleton tail
+        // then we need to reset the subchain itself
         const subchain = this.status.progress.subchains[0]
-        const parent = await this.getBlock(head.header.number - BigInt(1))
+        const parent = await this.getBlock(head.header.number - BigInt(1), true)
         if (
           subchain === undefined ||
           parent === undefined ||
-          !equalsBytes(parent.hash(), head.header.parentHash)
+          !equalsBytes(parent.hash(), head.header.parentHash) ||
+          parent.header.number < subchain.tail
         ) {
           const s = {
             head: head.header.number,
@@ -418,18 +422,33 @@ export class Skeleton extends MetaDBManager {
         continue
       } else {
         // Partially overwritten, trim the head to the overwritten size
+        this.status.progress.subchains[1].head = this.status.progress.subchains[0].tail - BigInt(1)
         this.config.logger.debug(
-          `Previous subchain partially overwritten head=${head} tail=${tail} next=${short(next)}`
+          `Previous subchain partially overwritten head=${head} tail=${tail} next=${short(
+            next
+          )} with newHead=${this.status.progress.subchains[1].head}`
         )
-        this.status.progress.subchains[1].head = this.status.progress.subchains[0].tail - BigInt(1)
         edited = true
       }
       // If the old subchain is an extension of the new one, merge the two
       // and let the skeleton syncer restart (to clean internal state)
 
-      const subChain1Head = await this.getBlock(this.status.progress.subchains[1].head)
+      // subchains are useful is subChain1Head is in skeleton only and its tail correct
+      const subChain1Head = await this.getBlock(this.status.progress.subchains[1].head, true)
+      // tail lookup can be from skeleton or chain
+      const subChain1Tail = await this.getBlock(this.status.progress.subchains[1].tail)
       if (
-        subChain1Head !== undefined &&
+        subChain1Head === undefined ||
+        subChain1Tail === undefined ||
+        !equalsBytes(subChain1Tail.header.parentHash, this.status.progress.subchains[1].next)
+      ) {
+        // if subChain1Head is not in the skeleton that all previous subchains are not useful
+        // and better to junk
+        this.config.logger.debug(
+          `Removing all previous subchains as skeleton missing block at previous subchain head=${this.status.progress.subchains[1].head}`
+        )
+        this.status.progress.subchains.splice(1, this.status.progress.subchains.length - 1)
+      } else if (
         equalsBytes(subChain1Head.hash(), this.status.progress.subchains[0].next) === true
       ) {
         // only merge is we can integrate a big progress, as each merge leads
@@ -565,13 +584,14 @@ export class Skeleton extends MetaDBManager {
     })
   }
 
-  private async backStep(): Promise<bigint | null> {
+  private async backStep(fromBlock: bigint): Promise<bigint | null> {
     try {
       if (this.config.skeletonFillCanonicalBackStep <= 0) return null
       const { head, tail } = this.bounds()
+      // by default we try back stepping from tail or fromBlock whichever is bigger
+      let newTail: bigint | null = tail < fromBlock ? fromBlock : tail
 
       let tailBlock
-      let newTail: bigint | null = tail
       do {
         newTail = newTail + BigInt(this.config.skeletonFillCanonicalBackStep)
         tailBlock = await this.getBlock(newTail, true)
@@ -597,6 +617,7 @@ export class Skeleton extends MetaDBManager {
         return null
       }
     } finally {
+      this.status.canonicalHeadReset = true
       this.status.linked = await this.checkLinked()
     }
   }
@@ -646,7 +667,8 @@ export class Skeleton extends MetaDBManager {
           `fillCanonicalChain block number=${number} not found, backStepping`
         )
         await this.runWithLock<void>(async () => {
-          await this.backStep()
+          // backstep the subchain from the block that was not found
+          await this.backStep(number)
         })
         break
       }
@@ -661,6 +683,7 @@ export class Skeleton extends MetaDBManager {
           await this.chain.putBlocks([oldHead], true)
         }
       }
+
       if (numBlocksInserted !== 1) {
         this.config.logger.error(
           `Failed to put block number=${number} fork=${block.common.hardfork()} hash=${short(
@@ -694,7 +717,7 @@ export class Skeleton extends MetaDBManager {
           )
         }
         await this.runWithLock<void>(async () => {
-          await this.backStep()
+          await this.backStep(number)
         })
         break
       }

From 6047ba0c8f70dafff298a2b312bb1c7afe936324 Mon Sep 17 00:00:00 2001
From: harkamal <gajinder@g11.in>
Date: Tue, 5 Sep 2023 23:06:20 +0530
Subject: [PATCH 2/8] skip filling chain on duplicate sethead

---
 packages/client/src/sync/skeleton.ts | 9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)

diff --git a/packages/client/src/sync/skeleton.ts b/packages/client/src/sync/skeleton.ts
index b68739184d..3506c076a4 100644
--- a/packages/client/src/sync/skeleton.ts
+++ b/packages/client/src/sync/skeleton.ts
@@ -237,7 +237,7 @@ export class Skeleton extends MetaDBManager {
       const mayBeDupBlock = await this.getBlock(number)
       if (mayBeDupBlock !== undefined && equalsBytes(mayBeDupBlock.header.hash(), head.hash())) {
         this.config.logger.debug(
-          `Skeleton duplicate announcement tail=${lastchain.tail} head=${
+          `Skeleton duplicate ${force ? 'setHead' : 'announcement'} tail=${lastchain.tail} head=${
             lastchain.head
           } number=${number} hash=${short(head.hash())}`
         )
@@ -363,7 +363,12 @@ export class Skeleton extends MetaDBManager {
       if (force || init) {
         await this.writeSyncStatus()
       }
-      if (force && this.status.linked) {
+      if (
+        (force &&
+          this.status.linked &&
+          head.header.number > this.status.progress.subchains[0]?.head) ??
+        BigInt(0)
+      ) {
         void this.fillCanonicalChain()
       }
       // Earlier we were throwing on reorg, essentially for the purposes for killing the reverse fetcher

From 94b54aa89ae1ebb457e730da0fc196f1862a1e00 Mon Sep 17 00:00:00 2001
From: harkamal <gajinder@g11.in>
Date: Sat, 9 Sep 2023 14:41:47 +0530
Subject: [PATCH 3/8] apply nits

---
 packages/client/src/sync/skeleton.ts | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/packages/client/src/sync/skeleton.ts b/packages/client/src/sync/skeleton.ts
index 3506c076a4..82e989b028 100644
--- a/packages/client/src/sync/skeleton.ts
+++ b/packages/client/src/sync/skeleton.ts
@@ -438,7 +438,7 @@ export class Skeleton extends MetaDBManager {
       // If the old subchain is an extension of the new one, merge the two
       // and let the skeleton syncer restart (to clean internal state)
 
-      // subchains are useful is subChain1Head is in skeleton only and its tail correct
+      // subchains are useful if subChain1Head is in skeleton only and its tail correct
       const subChain1Head = await this.getBlock(this.status.progress.subchains[1].head, true)
       // tail lookup can be from skeleton or chain
       const subChain1Tail = await this.getBlock(this.status.progress.subchains[1].tail)
@@ -447,7 +447,7 @@ export class Skeleton extends MetaDBManager {
         subChain1Tail === undefined ||
         !equalsBytes(subChain1Tail.header.parentHash, this.status.progress.subchains[1].next)
       ) {
-        // if subChain1Head is not in the skeleton that all previous subchains are not useful
+        // if subChain1Head is not in the skeleton then all previous subchains are not useful
         // and better to junk
         this.config.logger.debug(
           `Removing all previous subchains as skeleton missing block at previous subchain head=${this.status.progress.subchains[1].head}`

From 1f5b246e0f7d6602503f8e749d808e0eac577fc3 Mon Sep 17 00:00:00 2001
From: harkamal <gajinder@g11.in>
Date: Tue, 12 Sep 2023 00:29:58 +0530
Subject: [PATCH 4/8] add beacon sync sim for incline client

---
 package-lock.json                             |  12 +-
 packages/block/src/index.ts                   |   1 +
 packages/client/package.json                  |   1 +
 packages/client/test/sim/beaconsync.md        |  26 +++
 packages/client/test/sim/beaconsync.spec.ts   | 220 ++++++++++++++++++
 packages/client/test/sim/configs/mainnet.json |   4 +-
 packages/client/test/sim/mainnet.spec.ts      |  51 ++--
 packages/client/test/sim/simutils.ts          | 151 +++++++++++-
 packages/client/test/sim/single-run.sh        |   9 +-
 packages/client/test/sim/snapsync.spec.ts     |   5 +-
 10 files changed, 451 insertions(+), 29 deletions(-)
 create mode 100644 packages/client/test/sim/beaconsync.md
 create mode 100644 packages/client/test/sim/beaconsync.spec.ts

diff --git a/package-lock.json b/package-lock.json
index 87d9461697..3b8eb2277a 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -7202,6 +7202,15 @@
         "node": ">=0.8.x"
       }
     },
+    "node_modules/eventsource": {
+      "version": "2.0.2",
+      "resolved": "https://registry.npmjs.org/eventsource/-/eventsource-2.0.2.tgz",
+      "integrity": "sha512-IzUmBGPR3+oUG9dUeXynyNmf91/3zUSJg1lCktzKw47OXuhco54U3r9B7O4XX+Rb1Itm9OZ2b0RkTs10bICOxA==",
+      "dev": true,
+      "engines": {
+        "node": ">=12.0.0"
+      }
+    },
     "node_modules/evp_bytestokey": {
       "version": "1.0.3",
       "resolved": "https://registry.npmjs.org/evp_bytestokey/-/evp_bytestokey-1.0.3.tgz",
@@ -15444,6 +15453,7 @@
         "@types/yargs": "^17.0.24",
         "constants-browserify": "^1.0.0",
         "crypto-browserify": "^3.12.0",
+        "eventsource": "^2.0.2",
         "file-replace-loader": "^1.2.0",
         "it-pair": "^1.0.0",
         "it-pushable": "^1.4.2",
@@ -15701,7 +15711,7 @@
       "version": "5.0.0",
       "license": "MPL-2.0",
       "bin": {
-        "rlp": "bin/rlp"
+        "rlp": "bin/rlp.cjs"
       },
       "engines": {
         "node": ">=18"
diff --git a/packages/block/src/index.ts b/packages/block/src/index.ts
index add7d33700..b6b4faa482 100644
--- a/packages/block/src/index.ts
+++ b/packages/block/src/index.ts
@@ -1,4 +1,5 @@
 export { Block } from './block.js'
+export { executionPayloadFromBeaconPayload } from './from-beacon-payload.js'
 export { BlockHeader } from './header.js'
 export { getDifficulty, valuesArrayToHeaderData } from './helpers.js'
 export * from './types.js'
diff --git a/packages/client/package.json b/packages/client/package.json
index 6e7ba92045..783067d754 100644
--- a/packages/client/package.json
+++ b/packages/client/package.json
@@ -98,6 +98,7 @@
     "@types/yargs": "^17.0.24",
     "constants-browserify": "^1.0.0",
     "crypto-browserify": "^3.12.0",
+    "eventsource": "^2.0.2",
     "file-replace-loader": "^1.2.0",
     "it-pair": "^1.0.0",
     "it-pushable": "^1.4.2",
diff --git a/packages/client/test/sim/beaconsync.md b/packages/client/test/sim/beaconsync.md
new file mode 100644
index 0000000000..5350010e1b
--- /dev/null
+++ b/packages/client/test/sim/beaconsync.md
@@ -0,0 +1,26 @@
+### Beaconsync sim setup
+
+## Prerequisites
+
+1. Bash terminal
+2. Docker (without sudo)
+3. `jq` & `curl` installed
+4. `ethereumjs-monorepo` codebase build via `npm i` (for e.g. at `/usr/app/ethereumjs`)
+
+You may pre-download docker images for lodestar (`docker pull chainsafe/lodestar:latest`) and geth (`docker pull ethereum/client-go:v1.11.6`) to avoid any test timeout issues.
+
+Note: All commands should be run from the `client` package directory root (so something like `/usr/app/ethereumjs/packages/client`)
+
+## How to run
+
+1. Cleanup some datadirs
+
+```bash
+rm -rf ./datadir (if you have had previous runs)
+``` 
+
+2. Run the sim
+
+```bash
+BEACON_SYNC=true  NETWORK=mainnet NETWORKID=1337903 ELCLIENT=geth npx vitest run test/sim/beaconsync.spec.ts
+```
\ No newline at end of file
diff --git a/packages/client/test/sim/beaconsync.spec.ts b/packages/client/test/sim/beaconsync.spec.ts
new file mode 100644
index 0000000000..adc556a52f
--- /dev/null
+++ b/packages/client/test/sim/beaconsync.spec.ts
@@ -0,0 +1,220 @@
+import { Common } from '@ethereumjs/common'
+import { bytesToHex, hexToBytes, parseGethGenesisState, privateToAddress } from '@ethereumjs/util'
+import debug from 'debug'
+import { Client } from 'jayson/promise'
+import { assert, describe, it } from 'vitest'
+
+import { Config } from '../../src/config.js'
+import { getLogger } from '../../src/logging.js'
+import { Event } from '../../src/types.js'
+
+import {
+  createInlineClient,
+  filterKeywords,
+  filterOutWords,
+  runTxHelper,
+  setupEngineUpdateRelay,
+  startNetwork,
+  waitForELStart,
+} from './simutils'
+
+import type { EthereumClient } from '../../src/client'
+import type { RlpxServer } from '../../src/net/server'
+
+const client = Client.http({ port: 8545 })
+
+const network = 'mainnet'
+const networkJson = require(`./configs/${network}.json`)
+const common = Common.fromGethGenesis(networkJson, { chain: network })
+const customGenesisState = parseGethGenesisState(networkJson)
+
+const pkey = hexToBytes('0xae557af4ceefda559c924516cabf029bedc36b68109bf8d6183fe96e04121f4e')
+// 0x97C9B168C5E14d5D369B6D88E9776E5B7b11dcC1
+const sender = bytesToHex(privateToAddress(pkey))
+
+let ejsClient: EthereumClient | null = null
+let beaconSyncRelayer: any = null
+
+// This account doesn't exist in the genesis so starting balance is zero
+const EOATransferToAccount = '0x3dA33B9A0894b908DdBb00d96399e506515A1009'
+let EOATransferToBalance = BigInt(0)
+
+export async function runTx(data: string, to?: string, value?: bigint) {
+  return runTxHelper({ client, common, sender, pkey }, data, to, value)
+}
+
+describe('simple mainnet test run', async () => {
+  if (process.env.EXTRA_CL_PARAMS === undefined) {
+    process.env.EXTRA_CL_PARAMS = `--params.CAPELLA_FORK_EPOCH 0`
+    process.env.GENESIS_DELAY = 5
+  }
+
+  // Better add it as a option in startnetwork
+  process.env.NETWORKID = `${common.networkId()}`
+  const { teardownCallBack, result } = await startNetwork(network, client, {
+    filterKeywords,
+    filterOutWords,
+    externalRun: process.env.EXTERNAL_RUN,
+    withPeer: process.env.WITH_PEER,
+  })
+
+  if (result.includes('Geth')) {
+    assert.ok(true, 'connected to Geth')
+  } else {
+    assert.fail('connected to wrong client')
+  }
+
+  const nodeInfo = (await client.request('admin_nodeInfo', [])).result
+  assert.ok(nodeInfo.enode !== undefined, 'fetched enode for peering')
+
+  console.log(`Waiting for network to start...`)
+  try {
+    await waitForELStart(client)
+    assert.ok(true, 'geth<>lodestar started successfully')
+  } catch (e) {
+    assert.fail('geth<>lodestar failed to start')
+    throw e
+  }
+
+  // ------------Sanity checks--------------------------------
+  it.skipIf(process.env.ADD_EOA_STATE === undefined)(
+    'add some EOA transfers',
+    async () => {
+      let balance = await client.request('eth_getBalance', [EOATransferToAccount, 'latest'])
+      assert.equal(
+        EOATransferToBalance,
+        BigInt(balance.result),
+        `fetched ${EOATransferToAccount} balance=${EOATransferToBalance}`
+      )
+      balance = await client.request('eth_getBalance', [EOATransferToAccount, 'latest'])
+
+      await runTx('', EOATransferToAccount, 1000000n)
+      EOATransferToBalance += 1000000n
+
+      balance = await client.request('eth_getBalance', [EOATransferToAccount, 'latest'])
+      assert.equal(BigInt(balance.result), EOATransferToBalance, 'sent a simple ETH transfer')
+      await runTx('', EOATransferToAccount, 1000000n)
+      EOATransferToBalance += 1000000n
+
+      balance = await client.request('eth_getBalance', [EOATransferToAccount, 'latest'])
+      assert.equal(BigInt(balance.result), EOATransferToBalance, 'sent a simple ETH transfer 2x')
+
+      balance = await client.request('eth_getBalance', [sender, 'latest'])
+      assert.ok(
+        balance.result !== undefined,
+        'remaining sender balance after transfers and gas fee'
+      )
+    },
+    2 * 60_000
+  )
+
+  it.skipIf(process.env.BEACON_SYNC === undefined)(
+    'setup beacon sync',
+    async () => {
+      // start client inline here for beacon sync
+      const peerBeaconUrl = 'http://127.0.0.1:9596'
+      const {
+        ejsInlineClient,
+        peerConnectedPromise,
+        beaconSyncRelayer: relayer,
+        // eslint-disable-next-line @typescript-eslint/no-use-before-define
+      } = (await createBeaconSyncClient(
+        common,
+        customGenesisState,
+        [nodeInfo.enode],
+        peerBeaconUrl
+      ).catch((e) => {
+        console.log(e)
+        return null
+      })) ?? {
+        ejsInlineClient: null,
+        peerConnectedPromise: Promise.reject('Client creation error'),
+      }
+      ejsClient = ejsInlineClient
+      beaconSyncRelayer = relayer
+      assert.ok(ejsClient !== null, 'ethereumjs client started')
+
+      const enode = (ejsClient!.server('rlpx') as RlpxServer)!.getRlpxInfo().enode
+      const res = await client.request('admin_addPeer', [enode])
+      assert.equal(res.result, true, 'successfully requested Geth add EthereumJS as peer')
+
+      const peerConnectTimeout = new Promise((_resolve, reject) => setTimeout(reject, 10000))
+      try {
+        await Promise.race([peerConnectedPromise, peerConnectTimeout])
+        assert.ok(true, 'connected to geth peer')
+      } catch (e) {
+        assert.fail('could not connect to geth peer in 10 seconds')
+      }
+    },
+    60_000
+  )
+
+  it.skipIf(process.env.BEACON_SYNC === undefined)(
+    'should beacon sync and finish',
+    async () => {
+      if (ejsClient !== null && beaconSyncRelayer !== null) {
+        // wait on the sync promise to complete if it has been called independently
+        const syncTimeout = new Promise((_resolve, reject) => setTimeout(reject, 8 * 60_000))
+        const beaconSyncPromise = beaconSyncRelayer.start()
+
+        try {
+          // call sync if not has been called yet
+          void ejsClient.services[0].synchronizer?.sync()
+          await Promise.race([beaconSyncPromise, syncTimeout])
+          assert(beaconSyncRelayer.status, 'SYNCED', 'beaconSyncRelayer should have synced client')
+          await ejsClient.stop()
+          assert.ok(true, 'completed beacon sync')
+        } catch (e) {
+          assert.fail('could not complete beacon sync in 8 minutes')
+        }
+      } else {
+        assert.fail('ethereumjs client not setup properly for snap sync')
+      }
+    },
+    10 * 60_000
+  )
+
+  it('network cleanup', async () => {
+    try {
+      await teardownCallBack()
+      assert.ok(true, 'network cleaned')
+    } catch (e) {
+      assert.fail('network not cleaned properly')
+    }
+  }, 60_000)
+})
+
+async function createBeaconSyncClient(
+  common: any,
+  customGenesisState: any,
+  bootnodes: any,
+  peerBeaconUrl: any,
+  datadir: any
+) {
+  // Turn on `debug` logs, defaults to all client logging
+  debug.enable(process.env.DEBUG_SNAP ?? '')
+  const logger = getLogger({ logLevel: 'debug' })
+  const config = new Config({
+    common,
+    transports: ['rlpx'],
+    bootnodes,
+    multiaddrs: [],
+    logger,
+    discDns: false,
+    discV4: false,
+    port: 30304,
+    maxFetcherJobs: 10,
+  })
+  const peerConnectedPromise = new Promise((resolve) => {
+    config.events.once(Event.PEER_CONNECTED, (peer: any) => resolve(peer))
+  })
+
+  const ejsInlineClient = await createInlineClient(config, common, customGenesisState, datadir)
+  const beaconSyncRelayer = await setupEngineUpdateRelay(ejsInlineClient, peerBeaconUrl)
+  return { ejsInlineClient, peerConnectedPromise, beaconSyncRelayer }
+}
+
+process.on('uncaughtException', (err, origin) => {
+  console.log({ err, origin })
+  process.exit()
+})
diff --git a/packages/client/test/sim/configs/mainnet.json b/packages/client/test/sim/configs/mainnet.json
index 4aaa0dbded..321a864e18 100644
--- a/packages/client/test/sim/configs/mainnet.json
+++ b/packages/client/test/sim/configs/mainnet.json
@@ -12,7 +12,9 @@
     "berlinBlock": 0,
     "londonBlock": 0,
     "mergeForkBlock": 0,
-    "terminalTotalDifficulty": 1
+    "shanghaiTime": 0,
+    "terminalTotalDifficulty": 1,
+    "terminalTotalDifficultyPassed": true
   },
   "alloc": {
     "0x0000000000000000000000000000000000000000": {
diff --git a/packages/client/test/sim/mainnet.spec.ts b/packages/client/test/sim/mainnet.spec.ts
index 90f00ee532..953fe85b29 100644
--- a/packages/client/test/sim/mainnet.spec.ts
+++ b/packages/client/test/sim/mainnet.spec.ts
@@ -25,6 +25,9 @@ export async function runTx(data: string, to?: string, value?: bigint) {
 }
 
 describe('simple mainnet test run', async () => {
+  if (process.env.EXTRA_CL_PARAMS === undefined) {
+    process.env.EXTRA_CL_PARAMS = '--params.CAPELLA_FORK_EPOCH 0'
+  }
   const { teardownCallBack, result } = await startNetwork(network, client, {
     filterKeywords,
     filterOutWords,
@@ -48,26 +51,30 @@ describe('simple mainnet test run', async () => {
 
   const blockHashes: string[] = []
   // ------------Sanity checks--------------------------------
-  it('Simple transfer - sanity check', async () => {
-    await runTx('', '0x3dA33B9A0894b908DdBb00d96399e506515A1009', 1000000n)
-    let balance = await client.request('eth_getBalance', [
-      '0x3dA33B9A0894b908DdBb00d96399e506515A1009',
-      'latest',
-    ])
-    assert.equal(BigInt(balance.result), 1000000n, 'sent a simple ETH transfer')
-    await runTx('', '0x3dA33B9A0894b908DdBb00d96399e506515A1009', 1000000n)
-    balance = await client.request('eth_getBalance', [
-      '0x3dA33B9A0894b908DdBb00d96399e506515A1009',
-      'latest',
-    ])
-    balance = await client.request('eth_getBalance', [
-      '0x3dA33B9A0894b908DdBb00d96399e506515A1009',
-      'latest',
-    ])
-    assert.equal(BigInt(balance.result), 2000000n, 'sent a simple ETH transfer 2x')
-    const latestBlock = await client.request('eth_getBlockByNumber', ['latest', false])
-    blockHashes.push(latestBlock.result.hash)
-  })
+  it(
+    'Simple transfer - sanity check',
+    async () => {
+      await runTx('', '0x3dA33B9A0894b908DdBb00d96399e506515A1009', 1000000n)
+      let balance = await client.request('eth_getBalance', [
+        '0x3dA33B9A0894b908DdBb00d96399e506515A1009',
+        'latest',
+      ])
+      assert.equal(BigInt(balance.result), 1000000n, 'sent a simple ETH transfer')
+      await runTx('', '0x3dA33B9A0894b908DdBb00d96399e506515A1009', 1000000n)
+      balance = await client.request('eth_getBalance', [
+        '0x3dA33B9A0894b908DdBb00d96399e506515A1009',
+        'latest',
+      ])
+      balance = await client.request('eth_getBalance', [
+        '0x3dA33B9A0894b908DdBb00d96399e506515A1009',
+        'latest',
+      ])
+      assert.equal(BigInt(balance.result), 2000000n, 'sent a simple ETH transfer 2x')
+      const latestBlock = await client.request('eth_getBlockByNumber', ['latest', false])
+      blockHashes.push(latestBlock.result.hash)
+    },
+    2 * 60_000
+  )
 
   it('Validate execution hashes present in beacon headers', async () => {
     const eth2res = await (await fetch('http://127.0.0.1:9596/eth/v1/beacon/headers')).json()
@@ -77,7 +84,7 @@ describe('simple mainnet test run', async () => {
       parseInt(eth2res.data[0].header.message.slot),
       blockHashes
     )
-  })
+  }, 60_000)
 
   it('should reset td', async () => {
     try {
@@ -86,5 +93,5 @@ describe('simple mainnet test run', async () => {
     } catch (e) {
       assert.fail('network not cleaned properly')
     }
-  })
+  }, 60_000)
 })
diff --git a/packages/client/test/sim/simutils.ts b/packages/client/test/sim/simutils.ts
index e629279886..c9e6f0d7e4 100644
--- a/packages/client/test/sim/simutils.ts
+++ b/packages/client/test/sim/simutils.ts
@@ -1,3 +1,4 @@
+import { executionPayloadFromBeaconPayload } from '@ethereumjs/block'
 import { Blockchain } from '@ethereumjs/blockchain'
 import { BlobEIP4844Transaction, FeeMarketEIP1559Transaction } from '@ethereumjs/tx'
 import {
@@ -16,10 +17,12 @@ import * as fs from 'fs/promises'
 import { Level } from 'level'
 import { execSync, spawn } from 'node:child_process'
 import * as net from 'node:net'
+import qs from 'qs'
 
 import { EthereumClient } from '../../src/client'
 import { Config } from '../../src/config'
 import { LevelDB } from '../../src/execution/level'
+import { RPCManager } from '../../src/rpc'
 
 import type { Common } from '@ethereumjs/common'
 import type { TransactionType, TxData, TxOptions } from '@ethereumjs/tx'
@@ -27,6 +30,24 @@ import type { ChildProcessWithoutNullStreams } from 'child_process'
 import type { Client } from 'jayson/promise'
 
 export const sleep = (ms: number) => new Promise((r) => setTimeout(r, ms))
+// This function switches between the native web implementation and a nodejs implemnetation
+export async function getEventSource(): Promise<typeof EventSource> {
+  // eslint-disable-next-line @typescript-eslint/strict-boolean-expressions
+  if (globalThis.EventSource) {
+    return EventSource
+  } else {
+    return (await import('eventsource')).default as unknown as typeof EventSource
+  }
+}
+
+/**
+ * Ethereum Beacon API requires the query with format:
+ * - arrayFormat: repeat `topic=topic1&topic=topic2`
+ */
+export function stringifyQuery(query: unknown): string {
+  return qs.stringify(query, { arrayFormat: 'repeat' })
+}
+
 // Initialize the kzg object with the kzg library
 initKZG(kzg, __dirname + '/../../src/trustedSetups/devnet6.txt')
 
@@ -407,9 +428,13 @@ export const runBlobTxsFromFile = async (client: Client, path: string) => {
   return txnHashes
 }
 
-export async function createInlineClient(config: any, common: any, customGenesisState: any) {
+export async function createInlineClient(
+  config: any,
+  common: any,
+  customGenesisState: any,
+  datadir: any = Config.DATADIR_DEFAULT
+) {
   config.events.setMaxListeners(50)
-  const datadir = Config.DATADIR_DEFAULT
   const chainDB = new Level<string | Uint8Array, string | Uint8Array>(
     `${datadir}/${common.chainName()}/chainDB`
   )
@@ -442,6 +467,128 @@ export async function createInlineClient(config: any, common: any, customGenesis
   return inlineClient
 }
 
+export async function setupEngineUpdateRelay(client: EthereumClient, peerBeaconUrl: string) {
+  // track head
+  const topics = ['head']
+  const EventSource = await getEventSource()
+  const query = stringifyQuery({ topics })
+  console.log({ query })
+  const eventSource = new EventSource(`${peerBeaconUrl}/eth/v1/events?${query}`)
+  const manager = new RPCManager(client, client.config)
+  const engineMethods = manager.getMethods(true)
+  console.log('engineMethods', Object.keys(engineMethods))
+
+  // possible values: STARTED, PAUSED, ERRORED, SYNCING, VALID
+  let syncState = 'PAUSED'
+  let errorMessage = ''
+  const updateState = (newState) => {
+    if (syncState !== 'PAUSED') {
+      syncState = newState
+    }
+  }
+
+  const playUpdate = async (payload, finalizedBlockHash, version) => {
+    if (version !== 'capella') {
+      throw Error('only capella replay supported yet')
+    }
+    console.log('playUpdate', payload, { finalizedBlockHash })
+
+    try {
+      const newPayloadRes = await engineMethods['engine_newPayloadV2']([payload])
+      if (
+        newPayloadRes.status === undefined ||
+        !['SYNCING', 'VALID', 'ACCEPTED'].includes(newPayloadRes.status)
+      ) {
+        throw Error(
+          `newPayload error: status${newPayloadRes.status} validationError=${newPayloadRes.validationError} error=${newPayloadRes.error}`
+        )
+      }
+
+      const fcUState = {
+        headBlockHash: payload.blockHash,
+        safeBlockHash: finalizedBlockHash,
+        finalizedBlockHash,
+      }
+      console.log({ fcUState })
+      const fcuRes = await engineMethods['engine_forkchoiceUpdatedV2']([fcUState])
+      if (
+        fcuRes.payloadStatus === undefined ||
+        !['SYNCING', 'VALID', 'ACCEPTED'].includes(newPayloadRes.status)
+      ) {
+        throw Error(`fcU error: error:${fcuRes.error} message=${fcuRes.message}`)
+      } else {
+        updateState(fcuRes.payloadStatus.status)
+      }
+    } catch (e) {
+      console.log('playUpdate error', e)
+      updateState('ERRORED')
+    }
+  }
+
+  // ignoring the actual even, just using it as trigger to feed
+  eventSource.addEventListener(topics[0], (async (_event: MessageEvent) => {
+    if (syncState === 'PAUSED') return
+    try {
+      // just fetch finalized updated, it has all relevant hashesh to fcU
+      const beaconFinalized = await (
+        await fetch(`${peerBeaconUrl}/eth/v1/beacon/light_client/finality_update`)
+      ).json()
+      console.log({ beaconFinalized: beaconFinalized.data?.finalized_header })
+      if (beaconFinalized.error !== undefined) {
+        if (beaconFinalized.message?.includes('No finality update available') === true) {
+          // waiting for finality
+          return
+        } else {
+          throw Error(beaconFinalized.message ?? 'finality update fetch error')
+        }
+      }
+
+      const beaconHead = await (await fetch(`${peerBeaconUrl}/eth/v2/beacon/blocks/head`)).json()
+
+      const payload = executionPayloadFromBeaconPayload(
+        beaconHead.data.message.body.execution_payload
+      )
+      console.log('beaconFinalized', beaconFinalized.data.finalized_header)
+      const finalizedBlockHash = beaconFinalized.data.finalized_header.execution.block_hash
+      console.log('playing update', { payload, finalizedBlockHash })
+
+      await playUpdate(payload, finalizedBlockHash, beaconHead.version)
+    } catch (e) {
+      console.log('errored -----', e)
+      updateState('ERRORED')
+      errorMessage = (e as Error).message
+    }
+  }) as EventListener)
+
+  const start = () => {
+    if (syncState === 'PAUSED') syncState = 'STARTED'
+    return new Promise((resolve, reject) => {
+      const resolveOnSynced = () => {
+        console.log('resolveOnSynced', { syncState })
+        if (syncState === 'VALID') {
+          resolve({ syncState })
+        } else if (syncState === 'INVALID') {
+          reject(Error(errorMessage))
+        }
+
+        client.config.events.removeListener(resolveOnSynced)
+      }
+      client.config.events.on(Event.CHAIN_UPDATED, resolveOnSynced)
+    })
+  }
+  const pause = () => {
+    syncState = 'PAUSED'
+  }
+
+  return {
+    syncState,
+    playUpdate,
+    eventSource,
+    start,
+    pause,
+  }
+}
+
 // To minimise noise on the spec run, selective filteration is applied to let the important events
 // of the testnet log to show up in the spec log
 export const filterKeywords = [
diff --git a/packages/client/test/sim/single-run.sh b/packages/client/test/sim/single-run.sh
index cee4fa2c2c..734f4da034 100755
--- a/packages/client/test/sim/single-run.sh
+++ b/packages/client/test/sim/single-run.sh
@@ -39,7 +39,7 @@ then
           echo "geth requires NETWORKID to be passed in env, exiting..."
           exit;
         fi;
-        ELCLIENT_IMAGE="ethereum/client-go:v1.11.6"
+        ELCLIENT_IMAGE="ethereum/client-go:v1.12.2"
         echo "ELCLIENT=$ELCLIENT using ELCLIENT_IMAGE=$ELCLIENT_IMAGE NETWORKID=$NETWORKID"
         ;;
       *)
@@ -233,8 +233,13 @@ then
     done;
   fi
 
+  if [ ! -n "$GENESIS_DELAY" ]
+  then
+    GENESIS_DELAY=30
+  fi;
+
   genTime="$(date +%s)"
-  genTime=$((genTime + 30))
+  genTime=$((genTime + $GENESIS_DELAY))
   echo $genTime > "$origDataDir/genesisTime"
   echo $GENESIS_HASH > "$origDataDir/genesisHash"
 else
diff --git a/packages/client/test/sim/snapsync.spec.ts b/packages/client/test/sim/snapsync.spec.ts
index 6459e51c69..7ebc338b5b 100644
--- a/packages/client/test/sim/snapsync.spec.ts
+++ b/packages/client/test/sim/snapsync.spec.ts
@@ -53,6 +53,9 @@ export async function runTx(data: string, to?: string, value?: bigint) {
 }
 
 describe('simple mainnet test run', async () => {
+  if (process.env.EXTRA_CL_PARAMS === undefined) {
+    process.env.EXTRA_CL_PARAMS = '--params.CAPELLA_FORK_EPOCH 0'
+  }
   // Better add it as a option in startnetwork
   process.env.NETWORKID = `${common.networkId()}`
   const { teardownCallBack, result } = await startNetwork(network, client, {
@@ -145,7 +148,7 @@ describe('simple mainnet test run', async () => {
     60_000
   )
 
-  it(
+  it.skipIf(process.env.SNAP_SYNC === undefined)(
     'should snap sync and finish',
     async () => {
       if (ejsClient !== null && snapCompleted !== undefined) {

From a2abdf7f087454d5c6a92da12c7a9de2ec617dab Mon Sep 17 00:00:00 2001
From: harkamal <gajinder@g11.in>
Date: Wed, 13 Sep 2023 14:37:34 +0530
Subject: [PATCH 5/8] get the beacon sync to resolve

---
 packages/client/test/sim/beaconsync.md      |  9 ++++--
 packages/client/test/sim/beaconsync.spec.ts |  5 ++--
 packages/client/test/sim/simutils.ts        | 32 +++++++++++----------
 3 files changed, 27 insertions(+), 19 deletions(-)

diff --git a/packages/client/test/sim/beaconsync.md b/packages/client/test/sim/beaconsync.md
index 5350010e1b..b0782c7c66 100644
--- a/packages/client/test/sim/beaconsync.md
+++ b/packages/client/test/sim/beaconsync.md
@@ -13,14 +13,19 @@ Note: All commands should be run from the `client` package directory root (so so
 
 ## How to run
 
-1. Cleanup some datadirs
+1. Cleanup some datadirs (if you have had previous runs)
 
 ```bash
-rm -rf ./datadir (if you have had previous runs)
+rm -rf ./datadir
 ``` 
 
 2. Run the sim
 
 ```bash
 BEACON_SYNC=true  NETWORK=mainnet NETWORKID=1337903 ELCLIENT=geth npx vitest run test/sim/beaconsync.spec.ts
+```
+
+or just
+```bash
+rm -rf ./datadir; DEBUG=ethjs,client:* BEACON_SYNC=true  NETWORK=mainnet NETWORKID=1337903 ELCLIENT=geth npx vitest run test/sim/beaconsync.spec.ts
 ```
\ No newline at end of file
diff --git a/packages/client/test/sim/beaconsync.spec.ts b/packages/client/test/sim/beaconsync.spec.ts
index adc556a52f..07bde66538 100644
--- a/packages/client/test/sim/beaconsync.spec.ts
+++ b/packages/client/test/sim/beaconsync.spec.ts
@@ -143,6 +143,7 @@ describe('simple mainnet test run', async () => {
         await Promise.race([peerConnectedPromise, peerConnectTimeout])
         assert.ok(true, 'connected to geth peer')
       } catch (e) {
+        console.log(e)
         assert.fail('could not connect to geth peer in 10 seconds')
       }
     },
@@ -160,8 +161,8 @@ describe('simple mainnet test run', async () => {
         try {
           // call sync if not has been called yet
           void ejsClient.services[0].synchronizer?.sync()
-          await Promise.race([beaconSyncPromise, syncTimeout])
-          assert(beaconSyncRelayer.status, 'SYNCED', 'beaconSyncRelayer should have synced client')
+          const syncResponse = await Promise.race([beaconSyncPromise, syncTimeout])
+          assert(syncResponse.syncState, 'SYNCED', 'beaconSyncRelayer should have synced client')
           await ejsClient.stop()
           assert.ok(true, 'completed beacon sync')
         } catch (e) {
diff --git a/packages/client/test/sim/simutils.ts b/packages/client/test/sim/simutils.ts
index c9e6f0d7e4..33f6bd4960 100644
--- a/packages/client/test/sim/simutils.ts
+++ b/packages/client/test/sim/simutils.ts
@@ -476,10 +476,10 @@ export async function setupEngineUpdateRelay(client: EthereumClient, peerBeaconU
   const eventSource = new EventSource(`${peerBeaconUrl}/eth/v1/events?${query}`)
   const manager = new RPCManager(client, client.config)
   const engineMethods = manager.getMethods(true)
-  console.log('engineMethods', Object.keys(engineMethods))
 
   // possible values: STARTED, PAUSED, ERRORED, SYNCING, VALID
   let syncState = 'PAUSED'
+  let pollInterval = null
   let errorMessage = ''
   const updateState = (newState) => {
     if (syncState !== 'PAUSED') {
@@ -491,7 +491,12 @@ export async function setupEngineUpdateRelay(client: EthereumClient, peerBeaconU
     if (version !== 'capella') {
       throw Error('only capella replay supported yet')
     }
-    console.log('playUpdate', payload, { finalizedBlockHash })
+    const fcUState = {
+      headBlockHash: payload.blockHash,
+      safeBlockHash: finalizedBlockHash,
+      finalizedBlockHash,
+    }
+    console.log('playUpdate', fcUState)
 
     try {
       const newPayloadRes = await engineMethods['engine_newPayloadV2']([payload])
@@ -504,12 +509,6 @@ export async function setupEngineUpdateRelay(client: EthereumClient, peerBeaconU
         )
       }
 
-      const fcUState = {
-        headBlockHash: payload.blockHash,
-        safeBlockHash: finalizedBlockHash,
-        finalizedBlockHash,
-      }
-      console.log({ fcUState })
       const fcuRes = await engineMethods['engine_forkchoiceUpdatedV2']([fcUState])
       if (
         fcuRes.payloadStatus === undefined ||
@@ -533,7 +532,6 @@ export async function setupEngineUpdateRelay(client: EthereumClient, peerBeaconU
       const beaconFinalized = await (
         await fetch(`${peerBeaconUrl}/eth/v1/beacon/light_client/finality_update`)
       ).json()
-      console.log({ beaconFinalized: beaconFinalized.data?.finalized_header })
       if (beaconFinalized.error !== undefined) {
         if (beaconFinalized.message?.includes('No finality update available') === true) {
           // waiting for finality
@@ -548,31 +546,35 @@ export async function setupEngineUpdateRelay(client: EthereumClient, peerBeaconU
       const payload = executionPayloadFromBeaconPayload(
         beaconHead.data.message.body.execution_payload
       )
-      console.log('beaconFinalized', beaconFinalized.data.finalized_header)
       const finalizedBlockHash = beaconFinalized.data.finalized_header.execution.block_hash
-      console.log('playing update', { payload, finalizedBlockHash })
 
       await playUpdate(payload, finalizedBlockHash, beaconHead.version)
     } catch (e) {
-      console.log('errored -----', e)
+      console.log('update fetch error', e)
       updateState('ERRORED')
       errorMessage = (e as Error).message
     }
   }) as EventListener)
 
   const start = () => {
+    if (pollInterval !== null) {
+      throw Error('Already waiting on sync')
+    }
     if (syncState === 'PAUSED') syncState = 'STARTED'
     return new Promise((resolve, reject) => {
       const resolveOnSynced = () => {
-        console.log('resolveOnSynced', { syncState })
+        console.log('resolve sync', { syncState })
         if (syncState === 'VALID') {
           resolve({ syncState })
+          pollInterval = null
         } else if (syncState === 'INVALID') {
+          console.log('rejected sync', { syncState })
           reject(Error(errorMessage))
+          pollInterval = null
         }
-
-        client.config.events.removeListener(resolveOnSynced)
       }
+
+      pollInterval = setInterval(resolveOnSynced, 6000)
       client.config.events.on(Event.CHAIN_UPDATED, resolveOnSynced)
     })
   }

From 046110ca454b06c3bc1c698af39855b755afb658 Mon Sep 17 00:00:00 2001
From: harkamal <gajinder@g11.in>
Date: Wed, 13 Sep 2023 17:35:39 +0530
Subject: [PATCH 6/8] fix breaking skeleton spec

---
 packages/client/src/sync/skeleton.ts       | 10 ++++------
 packages/client/test/sim/simutils.ts       |  2 +-
 packages/client/test/sync/skeleton.spec.ts | 15 ++++++---------
 3 files changed, 11 insertions(+), 16 deletions(-)

diff --git a/packages/client/src/sync/skeleton.ts b/packages/client/src/sync/skeleton.ts
index 82e989b028..58adfbbfff 100644
--- a/packages/client/src/sync/skeleton.ts
+++ b/packages/client/src/sync/skeleton.ts
@@ -322,7 +322,10 @@ export class Skeleton extends MetaDBManager {
           head.hash()
         )} force=${force}`
       )
+
+      const subchain0Head = this.status.progress.subchains[0]?.head ?? BigInt(0)
       const reorg = await this.processNewHead(head, force)
+
       if (force && reorg) {
         // It could just be a reorg at this head with previous tail preserved unless
         //   1. parent is not present in skeleton (it could be in chain for whatever reason) or
@@ -363,12 +366,7 @@ export class Skeleton extends MetaDBManager {
       if (force || init) {
         await this.writeSyncStatus()
       }
-      if (
-        (force &&
-          this.status.linked &&
-          head.header.number > this.status.progress.subchains[0]?.head) ??
-        BigInt(0)
-      ) {
+      if (force && this.status.linked && head.header.number > subchain0Head) {
         void this.fillCanonicalChain()
       }
       // Earlier we were throwing on reorg, essentially for the purposes for killing the reverse fetcher
diff --git a/packages/client/test/sim/simutils.ts b/packages/client/test/sim/simutils.ts
index 33f6bd4960..7b229378cd 100644
--- a/packages/client/test/sim/simutils.ts
+++ b/packages/client/test/sim/simutils.ts
@@ -563,7 +563,7 @@ export async function setupEngineUpdateRelay(client: EthereumClient, peerBeaconU
     if (syncState === 'PAUSED') syncState = 'STARTED'
     return new Promise((resolve, reject) => {
       const resolveOnSynced = () => {
-        console.log('resolve sync', { syncState })
+        console.log('resolve sync check', { syncState })
         if (syncState === 'VALID') {
           resolve({ syncState })
           pollInterval = null
diff --git a/packages/client/test/sync/skeleton.spec.ts b/packages/client/test/sync/skeleton.spec.ts
index 857cb7e938..a1c07ece63 100644
--- a/packages/client/test/sync/skeleton.spec.ts
+++ b/packages/client/test/sync/skeleton.spec.ts
@@ -178,14 +178,11 @@ describe('[Skeleton] / initSync', async () => {
     // header. We expect the old subchain to be truncated and a new chain
     // be created for the dangling head.
     {
-      name: 'The old subchain to be truncated and a new chain be created for the dangling head',
+      name: 'The old subchains to be truncated/cleared and a new chain be created for the dangling head',
       blocks: [block49B],
       oldState: [{ head: BigInt(100), tail: BigInt(5) }],
       head: block50,
-      newState: [
-        { head: BigInt(50), tail: BigInt(50) },
-        { head: BigInt(49), tail: BigInt(5) },
-      ],
+      newState: [{ head: BigInt(50), tail: BigInt(50) }],
     },
   ]
   for (const [testCaseIndex, testCase] of testCases.entries()) {
@@ -193,7 +190,7 @@ describe('[Skeleton] / initSync', async () => {
       const config = new Config({
         common,
         transports: [],
-        logger: getLogger({ loglevel: 'debug' }),
+        logger: getLogger({ logLevel: 'debug' }),
         accountCache: 10000,
         storageCache: 1000,
       })
@@ -309,7 +306,7 @@ describe('[Skeleton] / setHead', async () => {
       const config = new Config({
         common,
         transports: [],
-        logger: getLogger({ loglevel: 'debug' }),
+        logger: getLogger({ logLevel: 'debug' }),
         accountCache: 10000,
         storageCache: 1000,
       })
@@ -493,7 +490,7 @@ describe('[Skeleton] / setHead', async () => {
   })
 
   it('should fill the canonical chain after being linked to genesis', async () => {
-    const config = new Config({ common, transports: [] })
+    const config = new Config({ common, transports: [], logger: getLogger({ logLevel: 'debug' }) })
     const chain = await Chain.create({ config })
     ;(chain.blockchain as any)._validateBlocks = false
     const skeleton = new Skeleton({ chain, config, metaDB: new MemoryLevel() })
@@ -819,7 +816,7 @@ describe('[Skeleton] / setHead', async () => {
     const config = new Config({
       transports: [],
       common,
-      logger: getLogger({ loglevel: 'debug' }),
+      logger: getLogger({ logLevel: 'debug' }),
       accountCache: 10000,
       storageCache: 1000,
     })

From 315d3b08c69e2440c203a8ccf44c7790f1de6fb2 Mon Sep 17 00:00:00 2001
From: harkamal <gajinder@g11.in>
Date: Wed, 13 Sep 2023 18:18:28 +0530
Subject: [PATCH 7/8] fix reverse block fetcher

---
 packages/client/src/sync/skeleton.ts            |  2 +-
 .../sync/fetcher/reverseblockfetcher.spec.ts    | 17 ++++++++++++++++-
 2 files changed, 17 insertions(+), 2 deletions(-)

diff --git a/packages/client/src/sync/skeleton.ts b/packages/client/src/sync/skeleton.ts
index 58adfbbfff..9cb69e5863 100644
--- a/packages/client/src/sync/skeleton.ts
+++ b/packages/client/src/sync/skeleton.ts
@@ -448,7 +448,7 @@ export class Skeleton extends MetaDBManager {
         // if subChain1Head is not in the skeleton then all previous subchains are not useful
         // and better to junk
         this.config.logger.debug(
-          `Removing all previous subchains as skeleton missing block at previous subchain head=${this.status.progress.subchains[1].head}`
+          `Removing all previous subchains as skeleton missing block at previous subchain head=${this.status.progress.subchains[1].head} or its tail=${this.status.progress.subchains[1].tail}`
         )
         this.status.progress.subchains.splice(1, this.status.progress.subchains.length - 1)
       } else if (
diff --git a/packages/client/test/sync/fetcher/reverseblockfetcher.spec.ts b/packages/client/test/sync/fetcher/reverseblockfetcher.spec.ts
index de345249b8..05cd12de2d 100644
--- a/packages/client/test/sync/fetcher/reverseblockfetcher.spec.ts
+++ b/packages/client/test/sync/fetcher/reverseblockfetcher.spec.ts
@@ -5,6 +5,7 @@ import { assert, describe, it } from 'vitest'
 
 import { Chain } from '../../../src/blockchain/chain'
 import { Config } from '../../../src/config'
+import { getLogger } from '../../../src/logging'
 import { Skeleton } from '../../../src/sync'
 import { Event } from '../../../src/types'
 import { wait } from '../../integration/util'
@@ -221,6 +222,7 @@ describe('[ReverseBlockFetcher]', async () => {
       accountCache: 10000,
       storageCache: 1000,
       skeletonSubchainMergeMinimum: 0,
+      logger: getLogger({ logLevel: 'debug' }),
     })
     const pool = new PeerPool() as any
     const chain = await Chain.create({ config })
@@ -251,11 +253,24 @@ describe('[ReverseBlockFetcher]', async () => {
       },
       { setHardfork: true }
     )
+    const block4 = Block.fromBlockData(
+      {
+        header: { number: BigInt(4), difficulty: BigInt(1) },
+      },
+      { setHardfork: true }
+    )
+    const block5 = Block.fromBlockData(
+      {
+        header: { number: BigInt(5), difficulty: BigInt(1), parentHash: block4.hash() },
+      },
+      { setHardfork: true }
+    )
     ;(skeleton as any).status.progress.subchains = [
       { head: BigInt(100), tail: BigInt(50), next: block49.hash() },
-      { head: BigInt(48), tail: BigInt(5) },
+      { head: BigInt(48), tail: BigInt(5), next: block4.hash() },
     ]
     await (skeleton as any).putBlock(block47)
+    await (skeleton as any).putBlock(block5)
     await fetcher.store([block49, block48])
     assert.ok(
       (skeleton as any).status.progress.subchains.length === 1,

From e6457eb0c85c10a6e7f02f7d4648344d278bf18c Mon Sep 17 00:00:00 2001
From: harkamal <gajinder@g11.in>
Date: Wed, 13 Sep 2023 20:06:27 +0530
Subject: [PATCH 8/8] apply feeback

---
 packages/client/test/sim/beaconsync.md      | 4 ++--
 packages/client/test/sim/beaconsync.spec.ts | 4 ++--
 packages/client/test/sim/simutils.ts        | 7 +++----
 packages/client/test/sim/snapsync.md        | 2 +-
 4 files changed, 8 insertions(+), 9 deletions(-)

diff --git a/packages/client/test/sim/beaconsync.md b/packages/client/test/sim/beaconsync.md
index b0782c7c66..cdaaaadc99 100644
--- a/packages/client/test/sim/beaconsync.md
+++ b/packages/client/test/sim/beaconsync.md
@@ -2,12 +2,12 @@
 
 ## Prerequisites
 
-1. Bash terminal
+1. ZSH terminal
 2. Docker (without sudo)
 3. `jq` & `curl` installed
 4. `ethereumjs-monorepo` codebase build via `npm i` (for e.g. at `/usr/app/ethereumjs`)
 
-You may pre-download docker images for lodestar (`docker pull chainsafe/lodestar:latest`) and geth (`docker pull ethereum/client-go:v1.11.6`) to avoid any test timeout issues.
+You may pre-download docker images for lodestar (`docker pull chainsafe/lodestar:latest`) and geth (`docker pull ethereum/client-go:v1.12.2`) to avoid any test timeout issues.
 
 Note: All commands should be run from the `client` package directory root (so something like `/usr/app/ethereumjs/packages/client`)
 
diff --git a/packages/client/test/sim/beaconsync.spec.ts b/packages/client/test/sim/beaconsync.spec.ts
index 07bde66538..d108db0b98 100644
--- a/packages/client/test/sim/beaconsync.spec.ts
+++ b/packages/client/test/sim/beaconsync.spec.ts
@@ -169,7 +169,7 @@ describe('simple mainnet test run', async () => {
           assert.fail('could not complete beacon sync in 8 minutes')
         }
       } else {
-        assert.fail('ethereumjs client not setup properly for snap sync')
+        assert.fail('ethereumjs client not setup properly for beacon sync')
       }
     },
     10 * 60_000
@@ -193,7 +193,7 @@ async function createBeaconSyncClient(
   datadir: any
 ) {
   // Turn on `debug` logs, defaults to all client logging
-  debug.enable(process.env.DEBUG_SNAP ?? '')
+  debug.enable(process.env.DEBUG_SYNC ?? '')
   const logger = getLogger({ logLevel: 'debug' })
   const config = new Config({
     common,
diff --git a/packages/client/test/sim/simutils.ts b/packages/client/test/sim/simutils.ts
index 7b229378cd..8356db1258 100644
--- a/packages/client/test/sim/simutils.ts
+++ b/packages/client/test/sim/simutils.ts
@@ -30,10 +30,9 @@ import type { ChildProcessWithoutNullStreams } from 'child_process'
 import type { Client } from 'jayson/promise'
 
 export const sleep = (ms: number) => new Promise((r) => setTimeout(r, ms))
-// This function switches between the native web implementation and a nodejs implemnetation
+// This function switches between the native web implementation and a nodejs implementation
 export async function getEventSource(): Promise<typeof EventSource> {
-  // eslint-disable-next-line @typescript-eslint/strict-boolean-expressions
-  if (globalThis.EventSource) {
+  if (globalThis.EventSource !== undefined) {
     return EventSource
   } else {
     return (await import('eventsource')).default as unknown as typeof EventSource
@@ -528,7 +527,7 @@ export async function setupEngineUpdateRelay(client: EthereumClient, peerBeaconU
   eventSource.addEventListener(topics[0], (async (_event: MessageEvent) => {
     if (syncState === 'PAUSED') return
     try {
-      // just fetch finalized updated, it has all relevant hashesh to fcU
+      // just fetch finalized updated, it has all relevant hashes for fcU
       const beaconFinalized = await (
         await fetch(`${peerBeaconUrl}/eth/v1/beacon/light_client/finality_update`)
       ).json()
diff --git a/packages/client/test/sim/snapsync.md b/packages/client/test/sim/snapsync.md
index ea2f965935..75ca68b420 100644
--- a/packages/client/test/sim/snapsync.md
+++ b/packages/client/test/sim/snapsync.md
@@ -7,7 +7,7 @@
 3. `jq` & `curl` installed
 4. `ethereumjs-monorepo` codebase build via `npm i` (for e.g. at `/usr/app/ethereumjs`)
 
-You may pre-download docker images for lodestar (`docker pull chainsafe/lodestar:latest`) and geth (`docker pull ethereum/client-go:v1.11.6`) to avoid any test timeout issues.
+You may pre-download docker images for lodestar (`docker pull chainsafe/lodestar:latest`) and geth (`docker pull ethereum/client-go:v1.12.2`) to avoid any test timeout issues.
 
 Note: All commands should be run from the `client` package directory root (so something like `/usr/app/ethereumjs/packages/client`)