Improve client and service typing support.

Key changes
* Converted the following main typescript classes created by Node to
interfaces: Client, Entity, GuardCondition, Publisher, Rate,
Subscription
* Refactored Client and Service to generic interfaces
* Refactored rostsd_gen/index.js to produce ServiceConstructors, Service
and ServiceType types. All maps are generated with keys in alphabetical
order. Detects and ignores invalid actions and services.
* Updated service and client tests in test/type/main.ts

Author: wayneparrott

rostsd_gen/index.js

@@ -128,12 +128,12 @@ const subscription = node.createSubscription(
 subscription.topic;
 
 // ---- Service ----
-// $ExpectType Service
+// $ExpectType AddTwoIntsConstructor
 const service = node.createService(
-  TYPE_CLASS,
-  'abc',
+  'example_interfaces/srv/AddTwoInts',
+  'add_two_ints',
   {},
-  (request: rclnodejs.Message, response: rclnodejs.ServiceResponse) => {}
+  (request, response) => {}
 );
 
 // $ExpectType string
@@ -143,8 +143,8 @@ service.serviceName;
 service.options;
 
 // ---- Client ----
-// $ExpectType Client
-const client = node.createClient(TYPE_CLASS, 'abc');
+// $ExpectType Client<"example_interfaces/srv/AddTwoInts">
+const client = node.createClient('example_interfaces/srv/AddTwoInts', 'add_two_ints');
 
 // $ExpectType string
 client.serviceName;

test/types/main.ts

@@ -0,0 +1,13 @@
+/// <reference path='../../types/index.d.ts' />
+import * as rclnodejs from 'rclnodejs';
+
+
+// ---- Uint8Array ----
+const u8arr = rclnodejs.require('example_interfaces.msg.UInt8MultiArray') as rclnodejs.example_interfaces.msg.UInt8MultiArray;
+// $ExpectType number[] | Uint8Array
+u8arr.data;
+
+// ---- Uint8Array ----
+const u8arrx = rclnodejs.require('std_msgs.msg.UInt8MultiArray') as rclnodejs.std_msgs.msg.UInt8MultiArray;
+// $ExpectType number[] | Uint8Array
+u8arrx.data;

test/types/test.ts

@@ -2,14 +2,16 @@ declare module 'rclnodejs' {
   /**
    * A ROS service client.
    */
-  class Client extends Entity {
+  interface Client<T extends TypeClass<ServiceTypeClassName>> extends Entity {
     /**
      * Make a service request and wait for to be notified asynchronously through a callback.
      *
      * @param request - Request to be submitted.
      * @param callback - Callback for receiving the server response.
      */
-    sendRequest(request: Message, callback: Client.ResponseCallback): void;
+    sendRequest(
+      request: ServiceRequestMessage<T>, 
+      callback: Client.ResponseCallback<T>): void;
 
     /**
      * Checks if the service is ready.
@@ -40,6 +42,7 @@ declare module 'rclnodejs' {
   }
 
   namespace Client {
+
     /**
      * A callback for receiving a response from the service
      *
@@ -51,6 +54,7 @@ declare module 'rclnodejs' {
      * See {@link Client}
      * See {@link Service}
      */
-    export type ResponseCallback = (response: Message) => void;
+    export type ResponseCallback<T extends TypeClass<ServiceTypeClassName>> = 
+      (response: ServiceResponseMessage<T>) => void;
   }
 }

types/client.d.ts

@@ -2,7 +2,7 @@ declare module 'rclnodejs' {
   /**
    * A common object in RCL.
    */
-  class Entity {
+  interface Entity {
     options: object;
     readonly qos: QoS;
     readonly typedArrayEnabled: boolean;

types/entity.d.ts

@@ -3,7 +3,7 @@ declare module 'rclnodejs' {
    * A ROS guard condition containing a callback executed when the
    * guard condition is triggered.
    */
-  class GuardCondition extends Entity {
+  interface GuardCondition extends Entity {
     /**
      * Triggers the guard condition.
      */

types/guard_condition.d.ts

@@ -1,5 +1,3 @@
-import { MessageTypeClassName } from "rclnodejs";
-
 // eslint-disable-next-line spaced-comment
 /// <reference path="base.d.ts" />
 

types/index.d.ts

@@ -1,11 +1,4 @@
 /* eslint-disable camelcase */
-
-import { Clock, TypeClassName, MessageTypeClassName } from 'rclnodejs';
-import { Logging } from 'rclnodejs';
-import { Parameter, ParameterDescriptor, ParameterType } from 'rclnodejs';
-import { QoS } from 'rclnodejs';
-import { rcl_interfaces } from 'rclnodejs';
-
 declare module 'rclnodejs' {
   /**
    * Identifies type of ROS message such as msg or srv.
@@ -60,71 +53,6 @@ declare module 'rclnodejs' {
    */
   const DEFAULT_OPTIONS: Options;
 
-  /**
-   * A service response to a client request.
-   *
-   * @remarks
-   * You can use {@link response.template | response.template} to get an empty result message.
-   */
-  class ServiceResponse {
-    /**
-     * Get an empty response message object.
-     * The template will be a message of type: <pkg>.srv.<serviceTypeClass>_Response.
-     * e.g., example_interface/srv/AddTwoInts_Response
-     */
-    readonly template: Message;
-
-    /**
-     * The service that this response object is attaching to.
-     */
-    readonly service: Service;
-
-    /**
-     * Send this response to client (the service caller)
-     *
-     * @param  response - Response message.
-     *
-     * @remarks
-     * see {@link Response.template}
-     */
-    send(response: Message): void;
-  }
-
-  /**
-   * A callback for receiving published messages.
-   *
-   * @param message - The published message.
-   *
-   * @remarks
-   * See {@link Node#createSubscription | Node.createSubscription}
-   * See {@link Node#createPublisher | Node.createPublisher}
-   * See {@link Publisher}
-   * See {@link Subscription}
-   */
-  type SubscriptionCallback<T extends TypeClass<MessageTypeClassName>> =
-    // * @param message - The published message
-    (message: MessageType<T> | Buffer) => void;
-
-  /**
-   * Callback for receiving service requests from a client.
-   *
-   * @param request - The request sent to the service
-   * @param response - The response to the client.
-   *
-   * @remarks
-   * Use {@link Response.send | response.send()} to send response object to client
-   *
-   * See {@link Node.createService | Node.createService}
-   * See {@link Client.sendRequest | Client.sendRequest}
-   * See {@link Client}
-   * See {@link Service}
-   * See {@link Response.send | Response.send}
-   */
-  type ServiceRequestCallback = (
-    request: Message,
-    response: ServiceResponse
-  ) => void;
-
   /**
    * Callback for receiving periodic interrupts from a Timer.
    *
@@ -283,7 +211,7 @@ declare module 'rclnodejs' {
       topic: string,
       options: Options,
       callback: SubscriptionCallback<T>
-    ): Subscription;
+    ): Subscription
 
     /**
      * Create a Client for making server requests.
@@ -293,11 +221,11 @@ declare module 'rclnodejs' {
      * @param options - The options argument used to parameterize the client.
      * @returns New instance of Client.
      */
-    createClient(
-      typeClass: TypeClass,
+    createClient<T extends TypeClass<ServiceTypeClassName>>(
+      typeClass: T,
       serviceName: string,
       options?: Options
-    ): Client;
+    ): Client<T>;
 
     /**
      * Create a Service.
@@ -308,12 +236,12 @@ declare module 'rclnodejs' {
      * @param callback - Notified for receiving incoming requests.
      * @returns An instance of Service.
      */
-    createService(
-      typeClass: TypeClass,
+    createService<T extends TypeClass<ServiceTypeClassName>>(
+      typeClass: T,
       serviceName: string,
       options: Options,
-      callback: ServiceRequestCallback
-    ): Service;
+      callback: ServiceRequestHandler<T>
+    ): ServiceType<T>;
 
     /**
      * Create a guard condition.
@@ -335,7 +263,7 @@ declare module 'rclnodejs' {
      *
      * @param publisher - Publisher to be destroyed.
      */
-    destroyPublisher<T extends MessageTypeClassName>(publisher: Publisher<T>): void;
+    destroyPublisher<T extends TypeClass<MessageTypeClassName>>(publisher: Publisher<T>): void;
 
     /**
      * Destroy a Subscription.
@@ -349,7 +277,7 @@ declare module 'rclnodejs' {
      *
      * @param client - Client to be destroyed.
      */
-    destroyClient(client: Client): void;
+    destroyClient<T extends TypeClass<ServiceTypeClassName>>(client: Client<T>): void;
 
     /**
      * Destroy a Service.

types/node.d.ts

@@ -1,10 +1,8 @@
-import { MessageTypeClassName } from 'rclnodejs';
-
 declare module 'rclnodejs' {
   /**
    * A ROS Publisher that publishes messages on a topic.
    */
-  class Publisher<T extends TypeClass<MessageTypeClassName>> extends Entity {
+  interface Publisher<T extends TypeClass<MessageTypeClassName>> extends Entity {
     /**
      * Topic on which messages are published.
      */

types/publisher.d.ts

@@ -28,7 +28,7 @@ declare module 'rclnodejs' {
    *   }
    * }
    */
-  export class Rate {
+  export interface Rate {
     /**
      * Get the frequency in hertz (hz) of this timer.
      *