[GnoVM] TestSetRealm not working properly in gno test

[leohhhn]

Description

Example package:

package example

import "std"

func GetPrevRealm() std.Realm {
	return std.PrevRealm()
}

Example tests:

package example

import (
	"std"
	"testing"

	"gno.land/p/demo/testutils"
)

func TestGetPrevRealmUser(t *testing.T) {
	alice := testutils.TestAddress("alice")
	std.TestSetRealm(std.NewUserRealm(alice))

	got := GetPrevRealm().Addr()

	if alice != got {
		t.Fatalf("expected %s, got %s", alice, got)
	}
}

func TestGetPrevRealmCode(t *testing.T) {
	std.TestSetRealm(std.NewCodeRealm("gno.land/r/demo/users"))
	expected := "g17m4ga9t9dxn8uf06p3cahdavzfexe33ecg8v2s" // derived from the path above

	got := GetPrevRealm().Addr()

	if expected != got {
		t.Fatalf("expected %s, got %s", expected, got)
	}
}

Both tests fail with:

❯ gno test . -v
=== RUN   TestGetPrevRealmUser
expected g1v9kxjcm9ta047h6lta047h6lta047h6lzd40gh, got g1wymu47drhr0kuq2098m792lytgtj2nyx77yrsm
--- FAIL: TestGetPrevRealmUser (0.00s)
=== RUN   TestGetPrevRealmCode
expected g17m4ga9t9dxn8uf06p3cahdavzfexe33ecg8v2s, got g1wymu47drhr0kuq2098m792lytgtj2nyx77yrsm
--- FAIL: TestGetPrevRealmCode (0.00s)
.: test pkg: failed: "TestGetPrevRealmUser"; failed: "TestGetPrevRealmCode"
FAIL
FAIL    .       0.72s
FAIL
FAIL
FAIL: 0 build errors, 1 test errors

[thehowl]

see-also

gno/examples/gno.land/p/demo/ownable/ownable_test.gno

Line 13 in 5fdbce0

func TestNew(t *testing.T) {

[thehowl]

The problem concerns using TestSetRealm in p/. See the following commit, where the tests succeed: 799ed1c

Note that the solution to making TestSetRealm work in p/, is by making the call pass through another "mocked realm" first:

func TestSetRealm_UserRealm(t *testing.T) {
	alice := testutils.TestAddress("alice")
	std.TestSetRealm(std.NewUserRealm(alice))

	var got std.Address
	proxyRealm(func() {
		got = tests.GetPrevRealm().Addr()
	})

	if alice != got {
		t.Fatalf("expected %s, got %s", alice, got)
	}
}

func TestSetRealm_CodeRealm(t *testing.T) {
	std.TestSetRealm(std.NewCodeRealm("gno.land/r/demo/users"))
	expected := "g17m4ga9t9dxn8uf06p3cahdavzfexe33ecg8v2s" // derived from the path above

	var got std.Address
	proxyRealm(func() {
		got = tests.GetPrevRealm().Addr()
	})

	if expected != got.String() {
		t.Fatalf("expected %s, got %s", expected, got)
	}
}

func proxyRealm(f func()) {
	std.TestSetRealm(std.NewCodeRealm("gno.land/r/proxy"))
	f()
}

This is because of the way TestSetRealm works, which I don't think is entirely incorrect. The "Realm" changes only when a realm boundary is crossed; so if we're working with packages, it doesn't. Consequently, in the example you provided @leohhhn, calling PrevRealm will yield the OrigCaller, because the CurrentRealm is the one you set with TestSetRealm.

I'm considering whether to just make TestSetRealm set both CurrentRealm and PrevRealm, when called from a package. Packages cannot import realms, so this may be OK. Need to sleep on it, though.

[thehowl]

I plan to tackle this in a different way in #2425, with the ability to set both PrevRealm and CurrentRealm when creating a context, so that pure package testing can work properly