backends

README

Backends

Ethergo supports a wide variety of backends for testing contract and chain interactions. Which one you use depends on your needs. There is usually a trade-off between speed, requirements and visibility.

Backend	Description	Supports RPC Address	Supports Forking	Embedded (does not require Docker)	Speed
Anvil	Anvil is a dockerized-backend that supports a wide variety of options including forking, custom gas pricing, etc all configurable at boot time	✅	✅	❌	Slow boot, fast run
Geth	Geth is an embedded go-ethereum node. This is the equivelant of the geth --dev command.	✅	❌	✅	Fastish boot, fast run
Simulated	Geth simulated backend	✅	❌	✅	Practically instant

Documentation

Overview

Package backends provides different kinds of backends you can test against that conform to a common interface thesse allow you to test eth functionality against a variety of backends

Index

• type AuthType
• type ContractVerifier
• type SimulatedTestBackend

Types

type AuthType

type AuthType struct {
	// transaction options
	*bind.TransactOpts
	// PrivateKey used for the tx
	PrivateKey *ecdsa.PrivateKey
}

AuthType is the type used for authentication.

type ContractVerifier

type ContractVerifier interface {
	VerifyContract(contractType contracts.ContractType, contract contracts.DeployedContract) error
}

ContractVerifier is a hook used to verify contracts with a test provider.

type SimulatedTestBackend

type SimulatedTestBackend interface {
	// BackendName gets the name of the backend
	BackendName() string
	// T is the testing.T
	T() *testing.T
	// SetT sets the testing.T
	SetT(t *testing.T)
	// Manager is used for concurrent signing while generating nonce
	nonce.Manager
	// ContractVerifier are contract verification hooks
	ContractVerifier
	// WaitForConfirmation waits for a tx confirmation
	WaitForConfirmation(ctx context.Context, transaction *types.Transaction)
	// FundAccount funds an account address with an amount amount
	FundAccount(ctx context.Context, address common.Address, amount big.Int)
	// GetTxContext gets a signed transaction. If the address is `nil`, will fund a new account.
	GetTxContext(ctx context.Context, address *common.Address) (auth AuthType)
	// GetFundedAccount gets a funded account with requestBalance
	GetFundedAccount(ctx context.Context, requestBalance *big.Int) *keystore.Key
	// Chain is the Chain
	//nolint:staticcheck
	chain.Chain
	// Signer is the signer for the chain
	Signer() types.Signer
	// ImpersonateAccount impersonates an account. This is only supported on the anvil backend backends.
	ImpersonateAccount(ctx context.Context, address common.Address, transact func(opts *bind.TransactOpts) *types.Transaction) error
	// EVM is the evm client
	client.EVM
	// Store stores an account
	Store(key *keystore.Key)
}

SimulatedTestBackend is a strict subset of TestBackend that all backends must comply with. TODO: we need one of these for testnets so we can run e2e tests. This should source addresses from a single address.