feat: redesign kotlin verb interface

examples/kotlin/ftl-module-ad/src/main/kotlin/ftl/ad/Ad.kt

@@ -14,48 +14,46 @@ data class Ad(val redirectUrl: String, val text: String)
 data class AdRequest(val contextKeys: List<String>? = null)
 data class AdResponse(val ads: List<Ad>)
 
-class AdModule {
-  private val database: Map<String, Ad> = loadDatabase()
-
-  @Verb
-  @HttpIngress(Method.GET, "/get")
-  fun get(context: Context, req: HttpRequest<AdRequest>): HttpResponse<AdResponse, String> {
-    val ads: List<Ad> = when {
-        req.body.contextKeys != null -> contextualAds(req.body.contextKeys)
-        else -> randomAds()
-    }
-
-    return HttpResponse(status = 200, headers = emptyMap(), body = AdResponse(ads = ads))
+private val database: Map<String, Ad> = loadDatabase()
+
+@Verb
+@HttpIngress(Method.GET, "/get")
+fun get(context: Context, req: HttpRequest<AdRequest>): HttpResponse<AdResponse, String> {
+  val ads: List<Ad> = when {
+    req.body.contextKeys != null -> contextualAds(req.body.contextKeys)
+    else -> randomAds()
   }
 
-  private fun contextualAds(contextKeys: List<String>): List<Ad> {
-    return contextKeys.map { database[it] ?: throw Exception("no ad registered for this context key") }
-  }
+  return HttpResponse(status = 200, headers = emptyMap(), body = AdResponse(ads = ads))
+}
 
-  private fun randomAds(): List<Ad> {
-    val ads = mutableListOf<Ad>()
-    val random = Random()
-    repeat(MAX_ADS_TO_SERVE) {
-      ads.add(database.entries.elementAt(random.nextInt(database.size)).value)
-    }
-    return ads
-  }
+private fun contextualAds(contextKeys: List<String>): List<Ad> {
+  return contextKeys.map { database[it] ?: throw Exception("no ad registered for this context key") }
+}
 
-  companion object {
-    private const val MAX_ADS_TO_SERVE = 2
-    private val DATABASE = mapOf(
-      "hair" to Ad("/product/2ZYFJ3GM2N", "Hairdryer for sale. 50% off."),
-      "clothing" to Ad("/product/66VCHSJNUP", "Tank top for sale. 20% off."),
-      "accessories" to Ad("/product/1YMWWN1N4O", "Watch for sale. Buy one, get second kit for free"),
-      "footwear" to Ad("/product/L9ECAV7KIM", "Loafers for sale. Buy one, get second one for free"),
-      "decor" to Ad("/product/0PUK6V6EV0", "Candle holder for sale. 30% off."),
-      "kitchen" to Ad("/product/9SIQT8TOJO", "Bamboo glass jar for sale. 10% off.")
-    )
-
-    private fun loadDatabase(): Map<String, Ad> {
-      return DATABASE
-    }
-
-    inline fun <reified T> Gson.fromJson(json: String) = fromJson<T>(json, object : TypeToken<T>() {}.type)
+private fun randomAds(): List<Ad> {
+  val ads = mutableListOf<Ad>()
+  val random = Random()
+  repeat(MAX_ADS_TO_SERVE) {
+    ads.add(database.entries.elementAt(random.nextInt(database.size)).value)
   }
+  return ads
 }
+
+private const val MAX_ADS_TO_SERVE = 2
+private val DATABASE = mapOf(
+  "hair" to Ad("/product/2ZYFJ3GM2N", "Hairdryer for sale. 50% off."),
+  "clothing" to Ad("/product/66VCHSJNUP", "Tank top for sale. 20% off."),
+  "accessories" to Ad("/product/1YMWWN1N4O", "Watch for sale. Buy one, get second kit for free"),
+  "footwear" to Ad("/product/L9ECAV7KIM", "Loafers for sale. Buy one, get second one for free"),
+  "decor" to Ad("/product/0PUK6V6EV0", "Candle holder for sale. 30% off."),
+  "kitchen" to Ad("/product/9SIQT8TOJO", "Bamboo glass jar for sale. 10% off.")
+)
+
+private fun loadDatabase(): Map<String, Ad> {
+  return DATABASE
+}
+
+inline fun <reified T> Gson.fromJson(json: String) = fromJson<T>(json, object : TypeToken<T>() {}.type)
+
+

examples/kotlin/ftl-module-api/src/main/kotlin/ftl/api/Api.kt

@@ -53,48 +53,47 @@ private val todos = ConcurrentHashMap<Int, Todo>()
 private val idCounter = AtomicInteger()
 private val gson = makeGson()
 
-class Api {
-  private val headers = mapOf("Content-Type" to arrayListOf("application/json"))
+private val headers = mapOf("Content-Type" to arrayListOf("application/json"))
 
-  @Verb
-  @HttpIngress(Method.GET, "/api/status")
-  fun status(context: Context, req: HttpRequest<Empty>): HttpResponse<GetStatusResponse> {
-    return HttpResponse<GetStatusResponse>(status = 200, headers = mapOf(), body = GetStatusResponse("OK"))
-  }
+@Verb
+@HttpIngress(Method.GET, "/api/status")
+fun status(context: Context, req: HttpRequest<Empty>): HttpResponse<GetStatusResponse, String> {
+  return HttpResponse(status = 200, headers = mapOf(), body = GetStatusResponse("OK"))
+}
 
-  @Verb
-  @HttpIngress(Method.GET, "/api/todos/{id}")
-  fun getTodo(context: Context, req: HttpRequest<GetTodoRequest>): HttpResponse<GetTodoResponse> {
-    val todoId = req.pathParameters["id"]?.toIntOrNull()
-    val todo = todos[todoId]
-
-    return if (todo != null) {
-      HttpResponse<GetTodoResponse>(
-        status = 200,
-        headers = mapOf(),
-        body = GetTodoResponse(todo)
-      )
-    } else {
-      HttpResponse<GetTodoResponse>(status = 404, headers = mapOf(), body = GetTodoResponse(null))
-    }
-  }
+@Verb
+@HttpIngress(Method.GET, "/api/todos/{id}")
+fun getTodo(context: Context, req: HttpRequest<GetTodoRequest>): HttpResponse<GetTodoResponse, String> {
+  val todoId = req.pathParameters["id"]?.toIntOrNull()
+  val todo = todos[todoId]
 
-  @Verb
-  @HttpIngress(Method.POST, "/api/todos")
-  fun addTodo(context: Context, req: HttpRequest<CreateTodoRequest>): HttpResponse<CreateTodoResponse> {
-    val todoReq = req.body
-    val id = idCounter.incrementAndGet()
-    todos.put(
-      id, Todo(
-        id = id,
-        title = todoReq.title,
-      )
+  return if (todo != null) {
+    HttpResponse(
+      status = 200,
+      headers = mapOf(),
+      body = GetTodoResponse(todo)
     )
+  } else {
+    HttpResponse(status = 404, headers = mapOf(), error = "Not found")
+  }
+}
 
-    return HttpResponse<CreateTodoResponse>(
-      status = 201,
-      headers = headers,
-      body = CreateTodoResponse(id),
+@Verb
+@HttpIngress(Method.POST, "/api/todos")
+fun addTodo(context: Context, req: HttpRequest<CreateTodoRequest>): HttpResponse<CreateTodoResponse, String> {
+  val todoReq = req.body
+  val id = idCounter.incrementAndGet()
+  todos.put(
+    id, Todo(
+      id = id,
+      title = todoReq.title,
     )
-  }
+  )
+
+  return HttpResponse(
+    status = 201,
+    headers = headers,
+    body = CreateTodoResponse(id),
+  )
 }
+

examples/kotlin/ftl-module-echo/src/main/kotlin/ftl/echo/Echo.kt

@@ -1,21 +1,18 @@
 package ftl.echo
 
-import ftl.time.TimeModuleClient
-import ftl.time.TimeRequest
+import ftl.builtin.Empty
+import ftl.time.time
 import xyz.block.ftl.Context
-import xyz.block.ftl.Method
 import xyz.block.ftl.Verb
 
 class InvalidInput(val field: String) : Exception()
 
 data class EchoRequest(val name: String?)
 data class EchoResponse(val message: String)
 
-class Echo {
-  @Throws(InvalidInput::class)
-  @Verb
-  fun echo(context: Context, req: EchoRequest): EchoResponse {
-    val response = context.call(TimeModuleClient::time, TimeRequest)
-    return EchoResponse(message = "Hello, ${req.name ?: "anonymous"}! The time is ${response.time}.")
-  }
+@Throws(InvalidInput::class)
+@Verb
+fun echo(context: Context, req: EchoRequest): EchoResponse {
+  val response = context.call(::time, Empty())
+  return EchoResponse(message = "Hello, ${req.name ?: "anonymous"}! The time is ${response.time}.")
 }

integration/testdata/kotlin/database/Echo.kt

@@ -9,28 +9,25 @@ data class InsertRequest(val data: String)
 
 val db = Database("testdb")
 
-class Echo {
-
-  @Verb
-  fun insert(context: Context, req: InsertRequest): Empty {
-    persistRequest(req)
-    return Empty()
-  }
+@Verb
+fun insert(context: Context, req: InsertRequest): Empty {
+  persistRequest(req)
+  return Empty()
+}
 
-  fun persistRequest(req: InsertRequest) {
-    db.conn {
-      it.prepareStatement(
-        """
+fun persistRequest(req: InsertRequest) {
+  db.conn {
+    it.prepareStatement(
+      """
         CREATE TABLE IF NOT EXISTS requests
         (
           data TEXT,
           created_at TIMESTAMPTZ NOT NULL DEFAULT (NOW() AT TIME ZONE 'utc'),
           updated_at TIMESTAMPTZ NOT NULL DEFAULT (NOW() AT TIME ZONE 'utc')
        );
        """
-      ).execute()
-      it.prepareStatement("INSERT INTO requests (data) VALUES ('${req.data}');")
-        .execute()
-    }
+    ).execute()
+    it.prepareStatement("INSERT INTO requests (data) VALUES ('${req.data}');")
+      .execute()
   }
 }

integration/testdata/kotlin/externalcalls/Echo.kt

@@ -1,21 +1,19 @@
 package ftl.echo
 
-import ftl.echo2.Echo2ModuleClient
+import ftl.echo2.echo as echo2
 import xyz.block.ftl.Context
 import xyz.block.ftl.Verb
 
 data class EchoRequest(val name: String)
 data class EchoResponse(val message: String)
 
-class Echo {
-  @Verb
-  fun echo(context: Context, req: EchoRequest): EchoResponse {
-    return EchoResponse(message = "Hello, ${req.name}!")
-  }
+@Verb
+fun echo(context: Context, req: EchoRequest): EchoResponse {
+  return EchoResponse(message = "Hello, ${req.name}!")
+}
 
-  @Verb
-  fun call(context: Context, req: EchoRequest): EchoResponse {
-    val res = context.call(Echo2ModuleClient::echo, ftl.echo2.EchoRequest(name = req.name))
-    return EchoResponse(message = res.message)
-  }
+@Verb
+fun call(context: Context, req: EchoRequest): EchoResponse {
+  val res = context.call(::echo2, ftl.echo2.EchoRequest(name = req.name))
+  return EchoResponse(message = res.message)
 }