shiritori: Exception -> Enum

- return structured enum instead of exception
- refresh tests dependencies and lint rules

Author: proppy

functions/.eslintrc.json

@@ -1,6 +1,6 @@
 {
   "parserOptions": {
-    "ecmaVersion": 7,
+    "ecmaVersion": 8,
     "sourceType": "module"
   },
   "extends": ["semistandard"],

functions/index.js

@@ -28,9 +28,9 @@ admin.initializeApp();
 const corpus = 'noun';
 
 const dict = k => admin.database()
-      .ref(corpus).child(k)
-      .once('value')
-      .then(snap => snap.val());
+  .ref(corpus).child(k)
+  .once('value')
+  .then(snap => snap.val());
 
 const app = actionssdk({
   // リクエストとレスポンスをロギングする。
@@ -47,28 +47,27 @@ app.intent('actions.intent.MAIN', conv => {
   conv.ask('どうぞ、始めて下さい');
 });
 
-app.intent('actions.intent.TEXT', (conv, input) => {
-  return shiritori.interact(dict, input, conv.data.used)
-      .then(result => {
-        conv.data.used.unshift(input);
-        conv.data.used.unshift(result.word);
-        conv.ask(new SimpleResponse({
-          speech: result.word,
-          text: `${result.word} [${result.kana}]`
-        }));
-      })
-      .catch(reason => {
-        switch (reason.constructor) {
-          case shiritori.Win:
-            conv.close('すごい！あなたの勝ちです。');
-            break;
-          case shiritori.Bad:
-            conv.close('ざんねん。あなたの負けです。');
-            break;
-          default:
-            throw reason;
-        }
-      });
+app.intent('actions.intent.TEXT', async (conv, input) => {
+  const result = await shiritori.interact(dict, input, conv.data.used);
+  switch (result.state) {
+    case shiritori.state.CONTINUE:
+      conv.data.used.unshift(input);
+      conv.data.used.unshift(result.word);
+      conv.ask(new SimpleResponse({
+        speech: result.word,
+        text: `${result.word} [${result.kana}]`
+      }));
+      break;
+    case shiritori.state.LOOSE_N:
+    case shiritori.state.LOOSE_USED:
+    case shiritori.state.LOOSE_CHAIN:
+      conv.close('ざんねん。あなたの負けです。');
+      break;
+    case shiritori.state.WIN_N:
+    case shiritori.state.WIN_USED:
+      conv.close('すごい！あなたの勝ちです。');
+      break;
+  }
 });
 
 exports.shiritoriV3 = functions.https.onRequest(app);