LocalNodeManager Class
Manages the lifecycle and state of a local Anvil Ethereum node for testing. Handles dynamic port allocation, process management, and exposes a rich set of methods for manipulating the blockchain state.
Constructor
new LocalNodeManager(config?: NodeConfig)
Optional node configuration options. See Configuration for details. Properties
The allocated port number, or -1 if not started.
The RPC URL for the running node (e.g., http://localhost:12345).
Lifecycle Methods
start()
async start(): Promise<void>
const node = new LocalNodeManager()
await node.start()
console.log(`Node running at ${node.rpcUrl}`)
stop()
async stop(): Promise<void>
getPort()
Returns the allocated port number for this node instance, or null if not started.
const port = node.getPort()
// Use port for configuration
State Management Methods
snapshot()
async snapshot(): Promise<string>
revert().
const snapshotId = await node.snapshot()
// Make changes...
await node.revert(snapshotId)
revert()
async revert(snapshotId: string): Promise<void>
The ID returned from snapshot()
reset()
async reset(forkBlock?: bigint): Promise<void>
Optional block number to reset to (when in fork mode)
Mining Methods
mine()
async mine(blocks = 1): Promise<void>
// Mine 10 blocks
await node.mine(10)
setAutomine()
async setAutomine(enabled: boolean): Promise<void>
Whether to enable automatic mining
// Disable automine for manual control
await node.setAutomine(false)
Time Manipulation Methods
setNextBlockTimestamp()
async setNextBlockTimestamp(timestamp: number): Promise<void>
Unix timestamp in seconds
increaseTime()
async increaseTime(seconds: number): Promise<void>
Number of seconds to advance
// Advance time by 1 day
await node.increaseTime(86400)
setTime()
async setTime(timestamp: number): Promise<void>
Unix timestamp in seconds
Account Management Methods
getAccounts()
async getAccounts(): Promise<string[]>
const accounts = await node.getAccounts()
console.log(`Available accounts: ${accounts.length}`)
setBalance()
async setBalance(address: string, balance: bigint): Promise<void>
await node.setBalance(
"0x742d35Cc6634C0532925a3b844Bc9e7595f8fA65",
parseEther("100")
)
setNonce()
async setNonce(address: string, nonce: number): Promise<void>
impersonateAccount()
async impersonateAccount(address: string): Promise<void>
The address to impersonate
// Impersonate a whale address
await node.impersonateAccount("0xWhaleAddress")
stopImpersonatingAccount()
async stopImpersonatingAccount(address: string): Promise<void>
The address to stop impersonating
Contract Methods
setCode()
async setCode(address: string, code: string): Promise<void>
The contract bytecode (hex string)
setStorageAt()
async setStorageAt(
address: string,
slot: string,
value: string
): Promise<void>
The storage slot (hex string)
The value to store (hex string)
Gas Configuration Methods
setNextBlockBaseFeePerGas()
async setNextBlockBaseFeePerGas(fee: bigint): Promise<void>
setMinGasPrice()
async setMinGasPrice(price: bigint): Promise<void>
The minimum gas price in wei
Network Methods
setChainId()
async setChainId(chainId: number): Promise<void>
Next Steps
