fix(vm/keeper): improve error for non crossing msg call error

gno.land/pkg/integration/testdata/maketx_call_pure.txtar

@@ -18,13 +18,18 @@ stderr '"gnokey" error: --= Error =--\nData: invalid package path'
 stderr '"gnokey" error: --= Error =--\nData: invalid package path'
 
 # 4. normal call to realm ERROR (need crossing)
-! gnokey maketx call -pkgpath gno.land/r/foo/call_realm -func Render -gas-fee 1000000ugnot -gas-wanted 2000000 -broadcast -chainid=tendermint_test test1
-stderr 'wrong number of arguments in call to Render: want 0 got 1'
+! gnokey maketx call -pkgpath gno.land/r/foo/call_realm -func Render2 -gas-fee 1000000ugnot -gas-wanted 2000000 -broadcast -chainid=tendermint_test test1
+stderr 'function Render2 is non-crossing and cannot be called with MsgCall \(\/directly\). It can either be called with qeval, or via another code realm'
+
+# 5. normal call to realm ERROR (need crossing)
+! gnokey maketx call -pkgpath gno.land/r/foo/call_realm -func Render -args "" -gas-fee 1000000ugnot -gas-wanted 2000000 -broadcast -chainid=tendermint_test test1
+stderr 'function Render is non-crossing and cannot be called with MsgCall \(\/directly\). It can either be called with qeval, or via another code realm'
+
 # XXX: While the error is correct, the correct message should be something like the message below:
 # stderr 'cannot cross-call a non-crossing function gno.land/r/foo/call_realm.Render from <no realm>'
 
 # 5. normal eval realm SUCCESS
-gnokey query vm/qeval --data 'gno.land/r/foo/call_realm.Render()'
+gnokey query vm/qeval --data 'gno.land/r/foo/call_realm.Render2()'
 stdout 'ok'
 
 -- pure/package.gno --
@@ -36,6 +41,10 @@ func Hello() string {
 -- realm/realm.gno --
 package call_realm
 
-func Render() string {
-	return "ok"
+func Render(path string) string {
+	return path
 }
+
+func Render2() string {
+	return "ok"
+}

gno.land/pkg/sdk/vm/keeper.go

@@ -556,6 +556,10 @@ func (vm *VMKeeper) Call(ctx sdk.Context, msg MsgCall) (res string, err error) {
 	pl := gno.PackageNodeLocation(pkgPath)
 	pn := gnostore.GetBlockNode(pl).(*gno.PackageNode)
 	ft := pn.GetStaticTypeOf(gnostore, gno.Name(fnc)).(*gno.FuncType)
+	if len(ft.Params) == 0 || ft.Params[0].Type.String() != ".uverse.realm" {
+		panic(fmt.Sprintf("function %s is non-crossing and cannot be called with MsgCall (/directly). It can either be called with qeval, or via another code realm", fnc))
+	}
+
 	// Make main Package with imports.
 	mpn := gno.NewPackageNode("main", "", nil)
 	mpn.Define("pkg", gno.TypedValue{T: &gno.PackageType{}, V: pv})

gno.land/pkg/sdk/vm/keeper_test.go

@@ -931,6 +931,62 @@ func Echo(cur realm, msg string) string { // XXX remove crossing call ?
 	)
 }
 
+func TestNonCrossingCallError(t *testing.T) {
+	env := setupTestEnv()
+	ctx := env.vmk.MakeGnoTransactionStore(env.ctx)
+
+	// Give "addr1" some gnots.
+	addr := crypto.AddressFromPreimage([]byte("addr1"))
+	acc := env.acck.NewAccountWithAddress(ctx, addr)
+	env.acck.SetAccount(ctx, acc)
+	env.bankk.SetCoins(ctx, addr, initialBalance)
+	assert.True(t, env.bankk.GetCoins(ctx, addr).IsEqual(initialBalance))
+
+	// Create test package.
+	const pkgPath = "gno.land/r/test"
+	files := []*std.MemFile{
+		{Name: "gnomod.toml", Body: gnolang.GenGnoModLatest(pkgPath)},
+		{
+			Name: "test.gno",
+			Body: `package test
+
+func Echo(msg string) string {
+	return "echo:"+msg
+}
+
+func EmptyCall() {
+	return
+}
+
+`,
+		},
+	}
+	msg1 := NewMsgAddPackage(addr, pkgPath, files)
+	err := env.vmk.AddPackage(ctx, msg1)
+	assert.NoError(t, err)
+
+	// Call Echo function which is not a crossing call
+	coins := std.MustParseCoins(ugnot.ValueString(1))
+	msg2 := NewMsgCall(addr, coins, pkgPath, "Echo", []string{"hello world"})
+	assert.PanicsWithValue(
+		t,
+		"function Echo is non-crossing and cannot be called with MsgCall (/directly). It can either be called with qeval, or via another code realm",
+		func() {
+			env.vmk.Call(ctx, msg2)
+		},
+	)
+
+	// Call EmptyCall function which is not a crossing call
+	msg3 := NewMsgCall(addr, coins, pkgPath, "EmptyCall", []string{})
+	assert.PanicsWithValue(
+		t,
+		"function EmptyCall is non-crossing and cannot be called with MsgCall (/directly). It can either be called with qeval, or via another code realm",
+		func() {
+			env.vmk.Call(ctx, msg3)
+		},
+	)
+}
+
 func TestVMKeeperReinitialize(t *testing.T) {
 	env := setupTestEnv()
 	ctx := env.vmk.MakeGnoTransactionStore(env.ctx)