helloworld_test.go

package main

import (
	"math/big"
	"testing"

	"github.com/ethereum/go-ethereum/accounts/abi/bind"
	"github.com/ethereum/go-ethereum/accounts/abi/bind/backends"
	"github.com/ethereum/go-ethereum/common"
	"github.com/ethereum/go-ethereum/core"
	"github.com/ethereum/go-ethereum/crypto"
	"github.com/stretchr/testify/suite"
)

type TestSuite struct {
	suite.Suite // Designates this struct as a test suite
	auth        *bind.TransactOpts
	address     common.Address
	gAlloc      core.GenesisAlloc
	sim         *backends.SimulatedBackend
	instance    *Helloworld // Instance of our contract as a go object
}

func TestRunHelloworldSuite(t *testing.T) {
	suite.Run(t, new(TestSuite))
}

func (s *TestSuite) SetupTest() {
	// We don't need a Wallet/account specific key, just a general ecdsa one.
	key, _ := crypto.GenerateKey()

	// Create new keyed transactor
	s.auth = bind.NewKeyedTransactor(key)

	s.address = s.auth.From

	s.gAlloc = map[common.Address]core.GenesisAccount{
		s.address: {Balance: big.NewInt(10000000000)},
	}

	s.sim = backends.NewSimulatedBackend(s.gAlloc)

	ver := "1.0"
	// Run the Deploy<contract_name>(auth *bind.TransactOpts, backend bind.ContractBackend, _version string)
	// Returns a contractAddress common.Address, tx *types.Transaction
	// (which we discard because we don't need to locate this on our simulated blockchain)
	// a contract instance, and an error, which we check with Testify using s.Nil(err)
	_, _, instance, err := DerrployHelloworld(s.auth, s.sim, ver)

	// We assign the contract instance returned to s.instance so we can interact with it
	// with the rest of our tests
	s.instance = instance
	s.Nil(err)

	// Creates a block on our simulated blockchain
	s.sim.Commit()
}

// TestSay tests the Say() contract function
func (s *TestSuite) TestSay() {
	str, err := s.instance.Say(nil)
	s.Equal("hello etherworld", str)
	s.Nil(err)
}