feat(schema): testing utilities (#20705)

Co-authored-by: coderabbitai[bot] <136622811+coderabbitai[bot]@users.noreply.github.com>

schema/appdata/forwarder.go

@@ -0,0 +1,15 @@
+package appdata
+
+// PacketForwarder creates a listener which listens to all callbacks and forwards all packets to the provided
+// function. This is intended to be used primarily for tests and debugging.
+func PacketForwarder(f func(Packet) error) Listener {
+	return Listener{
+		InitializeModuleData: func(data ModuleInitializationData) error { return f(data) },
+		OnTx:                 func(data TxData) error { return f(data) },
+		OnEvent:              func(data EventData) error { return f(data) },
+		OnKVPair:             func(data KVPairData) error { return f(data) },
+		OnObjectUpdate:       func(data ObjectUpdateData) error { return f(data) },
+		StartBlock:           func(data StartBlockData) error { return f(data) },
+		Commit:               func(data CommitData) error { return f(data) },
+	}
+}

schema/appdata/forwarder_test.go

@@ -0,0 +1,39 @@
+package appdata
+
+import (
+	"reflect"
+	"testing"
+)
+
+func TestPacketForwarder(t *testing.T) {
+	var received []Packet
+	listener := PacketForwarder(func(packet Packet) error {
+		received = append(received, packet)
+		return nil
+	})
+
+	expected := []Packet{
+		ModuleInitializationData{},
+		StartBlockData{},
+		TxData{},
+		EventData{},
+		KVPairData{},
+		ObjectUpdateData{},
+		CommitData{},
+	}
+
+	for i, packet := range expected {
+		err := listener.SendPacket(packet)
+		if err != nil {
+			t.Fatal(err)
+		}
+
+		if len(received) != i+1 {
+			t.Fatalf("didn't receive packet %v", packet)
+		}
+
+		if !reflect.DeepEqual(received[i], packet) {
+			t.Fatalf("received packet %v, expected %v", received[i], packet)
+		}
+	}
+}