create CommandStream and first Command

src/test/kotlin/eventDemo/app/actions/TestHttpClient.kt

@@ -0,0 +1,25 @@
+package eventDemo.app.actions
+
+import eventDemo.plugins.UUIDSerializer
+import io.ktor.client.HttpClient
+import io.ktor.client.plugins.contentnegotiation.ContentNegotiation
+import io.ktor.serialization.kotlinx.json.json
+import io.ktor.server.testing.ApplicationTestBuilder
+import kotlinx.serialization.json.Json
+import kotlinx.serialization.modules.SerializersModule
+import java.util.UUID
+
+fun ApplicationTestBuilder.httpClient(): HttpClient {
+    return createClient {
+        install(ContentNegotiation) {
+            json(
+                Json {
+                    serializersModule =
+                        SerializersModule {
+                            contextual(UUID::class) { UUIDSerializer }
+                        }
+                },
+            )
+        }
+    }
+}