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, 22 insertions, 24 deletions

diff --git a/language-web/src/main/js/xtext/UpdateService.ts b/language-web/src/main/js/xtext/UpdateService.ts
index 9b672e79..fa48c5ab 100644
--- a/language-web/src/main/js/xtext/UpdateService.ts
+++ b/language-web/src/main/js/xtext/UpdateService.ts
@@ -11,10 +11,10 @@ import { ConditionVariable } from '../utils/ConditionVariable';
 import { getLogger } from '../utils/logger';
 import { Timer } from '../utils/Timer';
 import {
-  IContentAssistEntry,
-  isContentAssistResult,
-  isDocumentStateResult,
-  isInvalidStateIdConflictResult,
+  ContentAssistEntry,
+  contentAssistResult,
+  documentStateResult,
+  isConflictResult,
 } from './xtextServiceResults';
 
 const UPDATE_TIMEOUT_MS = 500;
@@ -116,11 +116,8 @@ export class UpdateService {
       serviceType: 'update',
       fullText: this.store.state.doc.sliceString(0),
     });
-    if (isDocumentStateResult(result)) {
-      return [result.stateId, undefined];
-    }
-    log.error('Unexpected full text update result:', result);
-    throw new Error('Full text update failed');
+    const { stateId } = documentStateResult.parse(result);
+    return [stateId, undefined];
   }
 
   /**
@@ -146,14 +143,14 @@ export class UpdateService {
         requiredStateId: this.xtextStateId,
         ...delta,
       });
-      if (isDocumentStateResult(result)) {
-        return [result.stateId, undefined];
+      const parsedDocumentStateResult = documentStateResult.safeParse(result);
+      if (parsedDocumentStateResult.success) {
+        return [parsedDocumentStateResult.data.stateId, undefined];
       }
-      if (isInvalidStateIdConflictResult(result)) {
+      if (isConflictResult(result, 'invalidStateId')) {
         return this.doFallbackToUpdateFullText();
       }
-      log.error('Unexpected delta text update result:', result);
-      throw new Error('Delta text update failed');
+      throw parsedDocumentStateResult.error;
     });
   }
 
@@ -171,7 +168,7 @@ export class UpdateService {
   async fetchContentAssist(
     params: Record<string, unknown>,
     signal: IAbortSignal,
-  ): Promise<IContentAssistEntry[]> {
+  ): Promise<ContentAssistEntry[]> {
     await this.prepareForDeltaUpdate();
     if (signal.aborted) {
       return [];
@@ -185,18 +182,19 @@ export class UpdateService {
           requiredStateId: this.xtextStateId,
           ...delta,
         });
-        if (isContentAssistResult(result)) {
-          return [result.stateId, result.entries];
+        const parsedContentAssistResult = contentAssistResult.safeParse(result);
+        if (parsedContentAssistResult.success) {
+          const { stateId, entries: resultEntries } = parsedContentAssistResult.data;
+          return [stateId, resultEntries];
         }
-        if (isInvalidStateIdConflictResult(result)) {
+        if (isConflictResult(result, 'invalidStateId')) {
           const [newStateId] = await this.doFallbackToUpdateFullText();
           // We must finish this state update transaction to prepare for any push events
           // before querying for content assist, so we just return `null` and will query
           // the content assist service later.
           return [newStateId, null];
         }
-        log.error('Unextpected content assist result with delta update', result);
-        throw new Error('Unexpexted content assist result with delta update');
+        throw parsedContentAssistResult.error;
       });
       if (entries !== null) {
         return entries;
@@ -214,11 +212,11 @@ export class UpdateService {
       ...params,
       requiredStateId: expectedStateId,
     });
-    if (isContentAssistResult(result) && result.stateId === expectedStateId) {
-      return result.entries;
+    const { stateId, entries } = contentAssistResult.parse(result);
+    if (stateId !== expectedStateId) {
+      throw new Error(`Unexpected state id, expected: ${expectedStateId} got: ${stateId}`);
     }
-    log.error('Unexpected content assist result', result);
-    throw new Error('Unexpected content assist result');
+    return entries;
   }
 
   private computeDelta() {