Example test runner: make script more readable / ensure examples do n…

…ot `process.exit` (#3585)

* devp2p/vm: ensure examples do not process.exit

* vm: fix genesis state example + make linter happy

* Update examples-runner: run per-file

* devp2p: try to exit dpt

* revert change in devp2p

* Merge remote-tracking branch 'origin/master' into fix-examples-test-runner

packages/vm/examples/run-blockchain.ts

@@ -93,9 +93,4 @@ async function putBlocks(blockchain: Blockchain, common: Common, data: typeof te
   }
 }
 
-main()
-  .then(() => process.exit(0))
-  .catch((err) => {
-    console.error(err)
-    process.exit(1)
-  })
+void main()

packages/vm/examples/run-solidity-contract.ts

@@ -227,9 +227,4 @@ async function main() {
   console.log('Everything ran correctly!')
 }
 
-main()
-  .then(() => process.exit(0))
-  .catch((err) => {
-    console.error(err)
-    process.exit(1)
-  })
+void main()

packages/vm/examples/vmWithGenesisState.ts

@@ -1,4 +1,3 @@
-import { createBlockchain } from '@ethereumjs/blockchain'
 import { Chain } from '@ethereumjs/common'
 import { getGenesis } from '@ethereumjs/genesis'
 import { createAddressFromString } from '@ethereumjs/util'
@@ -7,11 +6,16 @@ import { VM } from '@ethereumjs/vm'
 const main = async () => {
   const genesisState = getGenesis(Chain.Mainnet)
 
-  const blockchain = await createBlockchain({ genesisState })
-  const vm = await VM.create({ blockchain })
+  const vm = await VM.create()
+  await vm.stateManager.generateCanonicalGenesis!(genesisState)
   const account = await vm.stateManager.getAccount(
     createAddressFromString('0x000d836201318ec6899a67540690382780743280'),
   )
+
+  if (account === undefined) {
+    throw new Error('Account does not exist: failed to import genesis state')
+  }
+
   console.log(
     `This balance for account 0x000d836201318ec6899a67540690382780743280 in this chain's genesis state is ${Number(
       account?.balance,

scripts/examples-runner.ts

@@ -1,5 +1,5 @@
+import { readdirSync } from 'fs'
 import { extname, join } from 'path'
-import { readdir } from 'fs'
 
 const pkg = process.argv[3]
 if (!pkg) {
@@ -9,17 +9,21 @@ if (!pkg) {
 const examplesPath = `../packages/${pkg}/examples/`
 const path = join(__dirname, examplesPath)
 
-readdir(path, async (err, files) => {
-  if (err) {
-    throw new Error('Error loading examples directory: ' + err.message)
+const getExample = (fileName: string): Promise<NodeModule> | undefined => {
+  if (extname(fileName) === '.cts' || extname(fileName) === '.ts') {
+    return import(examplesPath + fileName)
   }
+}
 
-  const getTsFiles = (fileName: string): Promise<NodeModule> | undefined => {
-    if (extname(fileName) === '.cts' || extname(fileName) === '.ts') {
-      return import(examplesPath + fileName)
+const main = async () => {
+  const files = readdirSync(path)
+  for (const file of files) {
+    const runner = getExample(file)
+    if (runner !== undefined) {
+      console.log(` ---- Run example: ${file} ----`)
+      await runner
     }
   }
+}
 
-  const importedFiles = files.map(getTsFiles).filter((file) => file)
-  await Promise.all(importedFiles)
-})
+main()