Wrap candid marshalling within pocketic.UpdateCall.

pocketic/endpoints_test.go

@@ -100,6 +100,19 @@ func TestEndpoints(t *testing.T) {
 			}
 		})
 
+		t.Run("update", func(t *testing.T) {
+			if err := pic.UpdateCall(*canisterID, principal.AnonymousID, "void", nil, nil); err == nil {
+				t.Fatal()
+			}
+			var resp string
+			if err := pic.UpdateCall(*canisterID, principal.AnonymousID, "helloUpdate", []any{"world"}, []any{&resp}); err != nil {
+				t.Fatal(err)
+			}
+			if resp != "Hello, world!" {
+				t.Fatalf("unexpected response: %s", resp)
+			}
+		})
+
 		t.Run("get_time", func(t *testing.T) {
 			dt, err := pic.GetTime()
 			if err != nil {

pocketic/request.go

@@ -148,8 +148,16 @@ func (pic PocketIC) SubmitCallWithEP(
 }
 
 // UpdateCall executes an update call on a canister.
-func (pic PocketIC) UpdateCall(canisterID principal.Principal, sender principal.Principal, method string, payload []byte) ([]byte, error) {
-	return pic.updateCallWithEP(canisterID, &RawEffectivePrincipalCanisterID{CanisterID: canisterID.Raw}, sender, method, payload)
+func (pic PocketIC) UpdateCall(canisterID principal.Principal, sender principal.Principal, method string, args []any, ret []any) error {
+	payload, err := idl.Marshal(args)
+	if err != nil {
+		return err
+	}
+	raw, err := pic.updateCallWithEP(canisterID, &RawEffectivePrincipalCanisterID{CanisterID: canisterID.Raw}, sender, method, payload)
+	if err != nil {
+		return err
+	}
+	return idl.Unmarshal(raw, ret)
 }
 
 // canisterCall calls the canister endpoint with the provided arguments.