esbuild

Source: apps/esbuild · Package: @tevm/example-esbuild

A Node script bundled by esbuild. It shows the .sol → typed-contract pipeline in plain JavaScript (no TypeScript required) and the spread a read action into viem pattern.

Run it

pnpm install
cp apps/esbuild/example.env apps/esbuild/.env   # then fill in RPC_URL_MAINNET
export RPC_URL_MAINNET=https://eth.llamarpc.com
pnpm --filter @tevm/example-esbuild dev   # builds, then runs dist/index.js
pnpm --filter @tevm/example-esbuild test

The build

build.js

import { esbuildPluginTevm } from '@tevm/esbuild-plugin'
import { build } from 'esbuild'
 
build({
  entryPoints: ['src/index.js'],
  outdir: 'dist',
  minify: true,
  sourcemap: false,
  bundle: true,
  define: {
    'process.env.NODE_ENV': JSON.stringify(process.env.NODE_ENV ?? 'production'),
  },
  plugins: [esbuildPluginTevm()],
}).catch((e) => {
  console.error(e)
  process.exit(1)
})

esbuildPluginTevm() takes no required options. It reads foundry.toml (solc = "0.8.20" here) for the compiler version, and resolves @openzeppelin/contracts/... imports inside the Solidity through Node resolution.

Reading a contract

src/ownerOf.js

import { http, createPublicClient } from 'viem'
import { mainnet } from 'viem/chains'
import { ExampleContract } from './ExampleContract.sol'
import { addresses } from './addresses.js'
import { rpcUrls } from './constants.js'
 
export const publicClient = createPublicClient({
  chain: mainnet,
  transport: http(rpcUrls[mainnet.id]),
})
 
export const ownerOf = (tokenId = BigInt(1)) => {
  return publicClient.readContract({
    ...ExampleContract.read.ownerOf(tokenId),
    address: addresses[1],
  })
}

ExampleContract.read.ownerOf(tokenId) returns { abi, functionName, args }. Spreading it means the ABI, the function name, and the argument types are all derived from the Solidity source — rename ownerOf in the contract and this line stops type-checking.

src/index.js

import { ownerOf } from './ownerOf.js'
 
ownerOf().then(console.log).catch(console.error)

Environment handling

The RPC URL is validated at module load rather than at first request, so a bad configuration fails immediately with a readable error instead of a network error deep in a call stack:

src/constants.js

import { mainnet } from 'viem/chains'
import { z } from 'zod'
 
export const rpcUrls = {
  1: z
    .string()
    .url()
    .optional()
    .default(mainnet.rpcUrls.default.http[0])
    .parse(process.env.RPC_URL_MAINNET),
}

Typed addresses without TypeScript

src/addresses.js is plain JS; a hand-written src/addresses.d.ts gives it literal types, so addresses[1] narrows to the exact 0x… string that viem wants for an Address:

src/addresses.d.ts

export const addresses: {
  '1': '0xFBA3912Ca04dd458c843e2EE08967fC04f3579c2'
  '5': '0x1df10ec981ac5871240be4a94f250dd238b77901'
  '10': '0x1df10ec981ac5871240be4a94f250dd238b77901'
  '56': '0x1df10ec981ac5871240be4a94f250dd238b77901'
  '137': '0x1df10ec981ac5871240be4a94f250dd238b77901'
  '250': '0x1df10ec981ac5871240be4a94f250dd238b77901'
  '288': '0x1df10ec981ac5871240be4a94f250dd238b77901'
  '324': '0x1df10ec981ac5871240be4a94f250dd238b77901'
  '420': '0x1df10ec981ac5871240be4a94f250dd238b77901'
  '42161': '0x1df10ec981ac5871240be4a94f250dd238b77901'
  '80001': '0x1df10ec981ac5871240be4a94f250dd238b77901'
  '421613': '0x1df10ec981ac5871240be4a94f250dd238b77901'
}

See the esbuild example API reference for the exported surface.

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