chore(web): json validation with zod

Use the zod library instead of manually written type assertions for
validating json messages from the server. This makes it easier to add
and handle new messages.

1 files changed, 44 insertions, 23 deletions

diff --git a/language-web/src/main/js/xtext/XtextWebSocketClient.ts b/language-web/src/main/js/xtext/XtextWebSocketClient.ts
index 488e4b3b..2ce20a54 100644
--- a/language-web/src/main/js/xtext/XtextWebSocketClient.ts
+++ b/language-web/src/main/js/xtext/XtextWebSocketClient.ts
@@ -4,12 +4,13 @@ import { getLogger } from '../utils/logger';
 import { PendingTask } from '../utils/PendingTask';
 import { Timer } from '../utils/Timer';
 import {
-  isErrorResponse,
-  isOkResponse,
-  isPushMessage,
-  IXtextWebRequest,
+  xtextWebErrorResponse,
+  XtextWebRequest,
+  xtextWebOkResponse,
+  xtextWebPushMessage,
+  XtextWebPushService,
 } from './xtextMessages';
-import { isPongResult } from './xtextServiceResults';
+import { pongResult } from './xtextServiceResults';
 
 const XTEXT_SUBPROTOCOL_V1 = 'tools.refinery.language.web.xtext.v1';
 
@@ -32,7 +33,7 @@ export type ReconnectHandler = () => void;
 export type PushHandler = (
   resourceId: string,
   stateId: string,
-  service: string,
+  service: XtextWebPushService,
   data: unknown,
 ) => void;
 
@@ -192,11 +193,12 @@ export class XtextWebSocketClient {
     const ping = nanoid();
     log.trace('Ping', ping);
     this.send({ ping }).then((result) => {
-      if (isPongResult(result) && result.pong === ping) {
+      const parsedPongResult = pongResult.safeParse(result);
+      if (parsedPongResult.success && parsedPongResult.data.pong === ping) {
         log.trace('Pong', ping);
         this.pingTimer.schedule();
       } else {
-        log.error('Invalid pong');
+        log.error('Invalid pong:', parsedPongResult, 'expected:', ping);
         this.forceReconnectOnError();
       }
     }).catch((error) => {
@@ -222,7 +224,7 @@ export class XtextWebSocketClient {
     const message = JSON.stringify({
       id: messageId,
       request,
-    } as IXtextWebRequest);
+    } as XtextWebRequest);
     log.trace('Sending message', message);
     return new Promise((resolve, reject) => {
       const task = new PendingTask(resolve, reject, REQUEST_TIMEOUT_MS, () => {
@@ -248,23 +250,42 @@ export class XtextWebSocketClient {
       this.forceReconnectOnError();
       return;
     }
-    if (isOkResponse(message)) {
-      this.resolveRequest(message.id, message.response);
-    } else if (isErrorResponse(message)) {
-      this.rejectRequest(message.id, new Error(`${message.error} error: ${message.message}`));
-      if (message.error === 'server') {
-        log.error('Reconnecting due to server error: ', message.message);
+    const okResponse = xtextWebOkResponse.safeParse(message);
+    if (okResponse.success) {
+      const { id, response } = okResponse.data;
+      this.resolveRequest(id, response);
+      return;
+    }
+    const errorResponse = xtextWebErrorResponse.safeParse(message);
+    if (errorResponse.success) {
+      const { id, error, message: errorMessage } = errorResponse.data;
+      this.rejectRequest(id, new Error(`${error} error: ${errorMessage}`));
+      if (error === 'server') {
+        log.error('Reconnecting due to server error: ', errorMessage);
         this.forceReconnectOnError();
       }
-    } else if (isPushMessage(message)) {
-      this.onPush(
-        message.resource,
-        message.stateId,
-        message.service,
-        message.push,
-      );
+      return;
+    }
+    const pushMessage = xtextWebPushMessage.safeParse(message);
+    if (pushMessage.success) {
+      const {
+        resource,
+        stateId,
+        service,
+        push,
+      } = pushMessage.data;
+      this.onPush(resource, stateId, service, push);
     } else {
-      log.error('Unexpected websocket message', message);
+      log.error(
+        'Unexpected websocket message:',
+        message,
+        'not ok response because:',
+        okResponse.error,
+        'not error response because:',
+        errorResponse.error,
+        'not push message because:',
+        pushMessage.error,
+      );
       this.forceReconnectOnError();
     }
   }