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, 21 insertions, 10 deletions

diff --git a/language-web/src/main/js/xtext/OccurrencesService.ts b/language-web/src/main/js/xtext/OccurrencesService.ts
index d1dec9e9..bc865537 100644
--- a/language-web/src/main/js/xtext/OccurrencesService.ts
+++ b/language-web/src/main/js/xtext/OccurrencesService.ts
@@ -7,9 +7,9 @@ import { getLogger } from '../utils/logger';
 import { Timer } from '../utils/Timer';
 import { XtextWebSocketClient } from './XtextWebSocketClient';
 import {
-  isOccurrencesResult,
-  isServiceConflictResult,
-  ITextRegion,
+  isConflictResult,
+  occurrencesResult,
+  TextRegion,
 } from './xtextServiceResults';
 
 const FIND_OCCURRENCES_TIMEOUT_MS = 1000;
@@ -20,7 +20,7 @@ const CLEAR_OCCURRENCES_TIMEOUT_MS = 10;
 
 const log = getLogger('xtext.OccurrencesService');
 
-function transformOccurrences(regions: ITextRegion[]): IOccurrence[] {
+function transformOccurrences(regions: TextRegion[]): IOccurrence[] {
   const occurrences: IOccurrence[] = [];
   regions.forEach(({ offset, length }) => {
     if (length > 0) {
@@ -87,21 +87,32 @@ export class OccurrencesService {
       caretOffset: this.store.state.selection.main.head,
     });
     const allChanges = this.updateService.computeChangesSinceLastUpdate();
-    if (!allChanges.empty
-      || (isServiceConflictResult(result) && result.conflict === 'canceled')) {
+    if (!allChanges.empty || isConflictResult(result, 'canceled')) {
       // Stale occurrences result, the user already made some changes.
       // We can safely ignore the occurrences and schedule a new find occurrences call.
       this.clearOccurrences();
       this.findOccurrencesTimer.schedule();
       return;
     }
-    if (!isOccurrencesResult(result) || result.stateId !== this.updateService.xtextStateId) {
-      log.error('Unexpected occurrences result', result);
+    const parsedOccurrencesResult = occurrencesResult.safeParse(result);
+    if (!parsedOccurrencesResult.success) {
+      log.error(
+        'Unexpected occurences result',
+        result,
+        'not an OccurrencesResult: ',
+        parsedOccurrencesResult.error,
+      );
       this.clearOccurrences();
       return;
     }
-    const write = transformOccurrences(result.writeRegions);
-    const read = transformOccurrences(result.readRegions);
+    const { stateId, writeRegions, readRegions } = parsedOccurrencesResult.data;
+    if (stateId !== this.updateService.xtextStateId) {
+      log.error('Unexpected state id, expected:', this.updateService.xtextStateId, 'got:', stateId);
+      this.clearOccurrences();
+      return;
+    }
+    const write = transformOccurrences(writeRegions);
+    const read = transformOccurrences(readRegions);
     this.hasOccurrences = write.length > 0 || read.length > 0;
     log.debug('Found', write.length, 'write and', read.length, 'read occurrences');
     this.store.updateOccurrences(write, read);