use conversation type of app in middleware

src/service/dialogflow/_test/dialogflow.test.ts

@@ -283,6 +283,7 @@ test('app uses middleware using Object.assign', async t => {
     test(): void
   }
   const middleware: DialogflowMiddleware<
+    {}, {}, Contexts,
     TestMiddleware & DialogflowConversation<{}, {}, Contexts>
   > = conv => Object.assign(conv, {
     test() {
@@ -329,6 +330,7 @@ test('app uses async middleware using Object.assign', async t => {
     test(): void
   }
   const middleware: DialogflowMiddleware<
+    {}, {}, Contexts,
     TestMiddleware & DialogflowConversation<{}, {}, Contexts>
   > = async conv => Object.assign(conv, {
     test() {
@@ -367,6 +369,7 @@ test('app uses async middleware returning void', async t => {
     test(): void
   }
   const middleware: DialogflowMiddleware<
+    {}, {}, Contexts,
     TestMiddleware & DialogflowConversation<{}, {}, Contexts>
   > = async conv => {
     (conv as TestMiddleware & DialogflowConversation<{}, {}, Contexts>)
@@ -404,6 +407,7 @@ test('app uses async middleware returning promise', async t => {
     test(): void
   }
   const middleware: DialogflowMiddleware<
+    {}, {}, Contexts,
     TestMiddleware & DialogflowConversation<{}, {}, Contexts>
   > = conv => Promise.resolve(Object.assign(conv, {
     test() {
@@ -444,8 +448,8 @@ test('app gives middleware framework metadata', async t => {
   }
   const response = 'abcdefg1234567'
   let called = false
-  const middleware: DialogflowMiddleware<DialogflowConversation<{}, {}, Contexts>
-  > = (conv, framework) => {
+  const middleware: DialogflowMiddleware<{}, {}, Contexts> =
+    (conv, framework) => {
     called = true
     t.is(framework, metadata)
   }

src/service/dialogflow/dialogflow.ts

@@ -30,6 +30,7 @@ import { Contexts, Parameters } from './context'
 import { DialogflowConversation } from './conv'
 import { OAuth2Client } from 'google-auth-library'
 import { BuiltinFrameworkMetadata } from '../../framework'
+import {JsonObject} from '../../common'
 
 /** @public */
 export interface DialogflowIntentHandler<
@@ -79,17 +80,21 @@ export interface DialogflowHandlers<
 
 /** @public */
 export interface DialogflowMiddleware<
-  TConversationPlugin extends DialogflowConversation
+  TConvData = JsonObject,
+  TUserStorage = JsonObject,
+  TContexts extends Contexts = Contexts,
+  TConversation extends DialogflowConversation<TConvData, TUserStorage, TContexts> =
+    DialogflowConversation<TConvData, TUserStorage, TContexts>,
 > {
   (
     /** @public */
-    conv: DialogflowConversation,
+    conv: TConversation,
 
     /** @public */
     framework: BuiltinFrameworkMetadata,
-  ): (DialogflowConversation & TConversationPlugin) |
+  ): TConversation |
     void |
-    Promise<DialogflowConversation & TConversationPlugin> |
+    Promise<TConversation> |
     Promise<void>
 }
 
@@ -260,11 +265,21 @@ export interface DialogflowApp<
   ): this
 
   /** @hidden */
-  _middlewares: DialogflowMiddleware<DialogflowConversation<{}, {}, Contexts>>[]
+  _middlewares: DialogflowMiddleware<
+    TConvData,
+    TUserStorage,
+    TContexts,
+    TConversation
+  >[]
 
   /** @public */
-  middleware<TConversationPlugin extends DialogflowConversation<{}, {}, Contexts>>(
-    middleware: DialogflowMiddleware<TConversationPlugin>,
+  middleware(
+    middleware: DialogflowMiddleware<
+      TConvData,
+      TUserStorage,
+      TContexts,
+      TConversation
+    >,
   ): this
 
   /** @public */