[neotest] panic when trying to deploy contract that requests storage context in init()

[ixje]

Current Behavior

I was trying out neotest and figured I'd try to create tests for the nep-17 token in the examples folder.

token_test.go

package tokencontract

import (
	"testing"

	"github.com/nspcc-dev/neo-go/pkg/neotest"
	"github.com/nspcc-dev/neo-go/pkg/neotest/chain"
)

func newTokenClient(t *testing.T) *neotest.ContractInvoker {
	bc, acc := chain.NewSingle(t)
	e := neotest.NewExecutor(t, bc, acc, acc)
	c := neotest.CompileFile(t, e.CommitteeHash, ".", "token.yml")
	e.DeployContract(t, c, nil)
	return e.CommitteeInvoker(c.Hash)
}

func TestToken_Basics(t *testing.T) {
	c := newTokenClient(t)
	c.Signers = []neotest.Signer{c.NewAccount(t)}
	c.Invoke(t, "ANT", "symbol")
	c.Invoke(t, decimals, "decimals")
	c.Invoke(t, 11000000*multiplier, "totalSupply")
}

Trying to execute the test fail in the DeployContract call with the below error

panic: interface conversion: interface {} is nil, not storage.Context

goroutine 1 [running]:
github.com/nspcc-dev/neo-go/pkg/interop/storage.GetContext()
	/home/erik/go/pkg/mod/github.com/nspcc-dev/neo-go/pkg/interop@v0.0.0-20221202075445-cb5c18dc73eb/storage/storage.go:52 +0x5d
github.com/nspcc-dev/neo-go/examples/token.init.0()
	/home/erik/code/neo-go/examples/token/token.go:32 +0xd4

which is here

neo-go/examples/token/token.go

Line 32 in 2f54f17

ctx = storage.GetContext()

Expected Behavior

I expect no errors on deploy

Steps to Reproduce

1. Place the above code in this folder https://github.com/nspcc-dev/neo-go/blob/master/examples/token/ in a file called token_test.go
2. run TestToken_Basics

Your Environment

• Version used: 80fdb1c

[roman-khimov]

package tokencontract

Place the above code in this folder https://github.com/nspcc-dev/neo-go/blob/master/examples/token/ in a file called token_test.go

Well, that's the issue and it can't be fixed. You're creating a test file in the same Go module as the contract itself and this contract has an init(). So when the test module is compiled it gets the same init() inside which can't work in non-SC context.

You can try package tokencontract_test though. Since you don't (and shouldn't) import the smart contract package this should work by creating a different package that doesn't have any init().

[ixje]

Well, that's the issue and it can't be fixed. You're creating a test file in the same Go module as the contract itself and this contract has an init(). So when the test module is compiled it gets the same init() inside which can't work in non-SC context.

Oh I didn't know init() is some special function that always gets called.

You can try package tokencontract_test though. Since you don't (and shouldn't) import the smart contract package this should work by creating a different package that doesn't have any init().

I tried package tokencontract_test but the result is the same 🤔

[roman-khimov]

Apparently it gets compiled into the package_test anyway, even though it's not imported directly. Which is somewhat surprising to me, but golang/go#58823.

So, an additional folder/package is needed.