From ea08a81726eaa48da80040bad1721d6ea3caf774 Mon Sep 17 00:00:00 2001
From: Anna Shaleva <shaleva.ann@nspcc.ru>
Date: Fri, 16 Sep 2022 21:08:05 +0300
Subject: [PATCH] interop: add CallWithVersion helper

---
 pkg/compiler/interop_test.go         | 29 ++++++++++++++++++++++++++++
 pkg/interop/lib/contract/contract.go | 23 ++++++++++++++++++++++
 2 files changed, 52 insertions(+)
 create mode 100644 pkg/interop/lib/contract/contract.go

diff --git a/pkg/compiler/interop_test.go b/pkg/compiler/interop_test.go
index 74904dcb1..07a617560 100644
--- a/pkg/compiler/interop_test.go
+++ b/pkg/compiler/interop_test.go
@@ -13,6 +13,7 @@ import (
 	"github.com/nspcc-dev/neo-go/pkg/core/dao"
 	"github.com/nspcc-dev/neo-go/pkg/core/interop"
 	"github.com/nspcc-dev/neo-go/pkg/core/native"
+	"github.com/nspcc-dev/neo-go/pkg/core/native/nativenames"
 	"github.com/nspcc-dev/neo-go/pkg/core/state"
 	"github.com/nspcc-dev/neo-go/pkg/core/storage"
 	"github.com/nspcc-dev/neo-go/pkg/crypto/hash"
@@ -519,3 +520,31 @@ func TestCallTConversionErrors(t *testing.T) {
 		require.Error(t, err)
 	})
 }
+
+func TestCallWithVersion(t *testing.T) {
+	bc, acc := chain.NewSingle(t)
+	e := neotest.NewExecutor(t, bc, acc, acc)
+	src := `package foo
+		import (
+			"github.com/nspcc-dev/neo-go/pkg/interop"
+			"github.com/nspcc-dev/neo-go/pkg/interop/contract"
+			util "github.com/nspcc-dev/neo-go/pkg/interop/lib/contract"
+		)
+		func CallWithVersion(hash interop.Hash160, version int, method string) interface{} {
+			return util.CallWithVersion(hash, version, method, contract.All)
+		}`
+	ctr := neotest.CompileSource(t, e.CommitteeHash, strings.NewReader(src), &compiler.Options{Name: "Helper"})
+	e.DeployContract(t, ctr, nil)
+	c := e.CommitteeInvoker(ctr.Hash)
+
+	policyH := state.CreateNativeContractHash(nativenames.Policy)
+	t.Run("good", func(t *testing.T) {
+		c.Invoke(t, e.Chain.GetBaseExecFee(), "callWithVersion", policyH.BytesBE(), 0, "getExecFeeFactor")
+	})
+	t.Run("unknown contract", func(t *testing.T) {
+		c.InvokeFail(t, "unknown contract", "callWithVersion", util.Uint160{1, 2, 3}.BytesBE(), 0, "getExecFeeFactor")
+	})
+	t.Run("invalid version", func(t *testing.T) {
+		c.InvokeFail(t, "contract version mismatch", "callWithVersion", policyH.BytesBE(), 1, "getExecFeeFactor")
+	})
+}
diff --git a/pkg/interop/lib/contract/contract.go b/pkg/interop/lib/contract/contract.go
new file mode 100644
index 000000000..735db00ba
--- /dev/null
+++ b/pkg/interop/lib/contract/contract.go
@@ -0,0 +1,23 @@
+package contract
+
+import (
+	"github.com/nspcc-dev/neo-go/pkg/interop"
+	"github.com/nspcc-dev/neo-go/pkg/interop/contract"
+	"github.com/nspcc-dev/neo-go/pkg/interop/native/management"
+)
+
+// CallWithVersion is a utility function that executes the previously deployed
+// blockchain contract with the specified version (update counter) and hash
+// (20 bytes in BE form) using the provided arguments and call flags. It fails
+// if the contract has version mismatch. It returns whatever this contract
+// returns. This function uses `System.Contract.Call` syscall.
+func CallWithVersion(scriptHash interop.Hash160, version int, method string, f contract.CallFlag, args ...interface{}) interface{} {
+	cs := management.GetContract(scriptHash)
+	if cs == nil {
+		panic("unknown contract")
+	}
+	if cs.UpdateCounter != version {
+		panic("contract version mismatch")
+	}
+	return contract.Call(scriptHash, method, f, args...)
+}