refactor(editor): remove assertExists (#10615)

blocksuite/framework/store/src/__tests__/collection.unit.spec.ts

@@ -13,7 +13,6 @@ import {
   ParagraphBlockSchemaExtension,
   RootBlockSchemaExtension,
 } from './test-schema.js';
-import { assertExists } from './test-utils-dom.js';
 
 function createTestOptions() {
   const idGenerator = createAutoIncrementIdGenerator();
@@ -207,7 +206,9 @@ describe('basic', () => {
       const doc2 = collection2.getDoc('space:0', {
         extensions,
       });
-      assertExists(doc2);
+      if (!doc2) {
+        throw new Error('doc2 is not found');
+      }
       applyUpdate(doc2.spaceDoc, update);
       expect(serializCollection(collection2.doc)['spaces']).toEqual({
         'space:0': {

blocksuite/framework/store/src/__tests__/test-utils-dom.ts

@@ -65,13 +65,6 @@ export async function runOnce() {
   testCases = [];
 }
 
-// XXX: workaround typing issue in blobs/__tests__/test-entry.ts
-export function assertExists<T>(val: T | null | undefined): asserts val is T {
-  if (val === null || val === undefined) {
-    throw new Error('val does not exist');
-  }
-}
-
 export async function nextFrame() {
   return new Promise(resolve => requestAnimationFrame(resolve));
 }