CheckRuntimeVersion without function receiver

- No dependency on existing instance
- Closes temporary instance on exit
- Remove `CheckRuntimeVersion` from Instance interface

dot/rpc/subscription/listeners_test.go

@@ -351,12 +351,11 @@ func TestRuntimeChannelListener_Listen(t *testing.T) {
 	expectedInitialResponse.Method = "state_runtimeVersion"
 	expectedInitialResponse.Params.Result = expectedInitialVersion
 
-	instance := wasmer.NewTestInstance(t, runtime.NODE_RUNTIME)
 	polkadotRuntimeFilepath, err := runtime.GetRuntime(context.Background(), runtime.POLKADOT_RUNTIME)
 	require.NoError(t, err)
 	code, err := os.ReadFile(polkadotRuntimeFilepath)
 	require.NoError(t, err)
-	version, err := instance.CheckRuntimeVersion(code)
+	version, err := wasmer.CheckRuntimeVersion(code)
 	require.NoError(t, err)
 
 	expectedUpdatedVersion := modules.StateRuntimeVersionResponse{

dot/state/block.go

@@ -591,7 +591,7 @@ func (bs *BlockState) HandleRuntimeChanges(newState *rtstorage.TrieState,
 	codeSubBlockHash := bs.baseState.LoadCodeSubstitutedBlockHash()
 
 	if !codeSubBlockHash.Equal(common.Hash{}) {
-		newVersion, err := rt.CheckRuntimeVersion(code)
+		newVersion, err := wasmer.CheckRuntimeVersion(code)
 		if err != nil {
 			return err
 		}

lib/runtime/interface.go

@@ -16,7 +16,6 @@ import (
 // Instance is the interface a v0.8 runtime instance must implement
 type Instance interface {
 	UpdateRuntimeCode([]byte) error
-	CheckRuntimeVersion([]byte) (Version, error)
 	Stop()
 	NodeStorage() NodeStorage
 	NetworkService() BasicNetwork

lib/runtime/wasmer/instance.go

@@ -156,25 +156,31 @@ func (in *Instance) UpdateRuntimeCode(code []byte) (err error) {
 	return nil
 }
 
-// CheckRuntimeVersion calculates runtime Version for runtime blob passed in
-func (in *Instance) CheckRuntimeVersion(code []byte) (runtime.Version, error) {
-	in.mutex.Lock()
-	defer in.mutex.Unlock()
-
+// CheckRuntimeVersion finds the runtime version by initiating a temporary
+// runtime instance using the WASM code provided, and querying it.
+func CheckRuntimeVersion(code []byte) (version runtime.Version, err error) {
 	wasmInstance, allocator, err := setupVM(code)
 	if err != nil {
 		return nil, fmt.Errorf("setting up VM: %w", err)
 	}
 
-	in.ctx.Allocator = allocator // TODO we should no change the allocator of the parent instance
-	wasmInstance.SetContextData(in.ctx)
+	ctx := &runtime.Context{
+		Allocator: allocator,
+	}
+	wasmInstance.SetContextData(ctx)
 
 	instance := Instance{
 		vm:  wasmInstance,
-		ctx: in.ctx,
+		ctx: ctx,
+	}
+	defer instance.close()
+
+	version, err = instance.Version()
+	if err != nil {
+		return nil, fmt.Errorf("running runtime: %w", err)
 	}
 
-	return instance.Version()
+	return version, nil
 }
 
 var (

lib/runtime/wasmer/instance_test.go

@@ -36,14 +36,13 @@ func TestPointerSize(t *testing.T) {
 	require.Equal(t, in, res)
 }
 
-func TestInstance_CheckRuntimeVersion(t *testing.T) {
-	instance := NewTestInstance(t, runtime.NODE_RUNTIME)
+func Test_CheckRuntimeVersion(t *testing.T) {
 	polkadotRuntimeFilepath, err := runtime.GetRuntime(
 		context.Background(), runtime.POLKADOT_RUNTIME)
 	require.NoError(t, err)
 	code, err := os.ReadFile(polkadotRuntimeFilepath)
 	require.NoError(t, err)
-	version, err := instance.CheckRuntimeVersion(code)
+	version, err := CheckRuntimeVersion(code)
 	require.NoError(t, err)
 
 	expected := runtime.NewVersionData(