P2/P5: coordinate tabs and render feature preview

tests/facade.test.ts

@@ -3,7 +3,7 @@ import assert from 'node:assert/strict'
 import { strToU8, zipSync } from 'fflate'
 import { createMockFacade } from '../src/facade/mockFacade'
 import { PROJECT_SCHEMA_MIGRATIONS, PROJECT_SCHEMA_SQL, PROJECT_SCHEMA_VERSION } from '../src/facade/projectSchema'
-import { PersistenceWriteQueue, ProjectAutosaveScheduler } from '../src/facade/projectStore'
+import { createSqliteProjectPersistence, PersistenceWriteQueue, ProjectAutosaveScheduler } from '../src/facade/projectStore'
 import { DependencyGraph } from '../src/facade/dependencyGraph'
 import { evaluateQuantityExpression, quantityFromNumber } from '../src/facade/units'
 import { createEdgeSubshapeRefs, createSubshapeRefs, createVertexSubshapeRefs, matchSubshapes, signatureForEdge, signatureForFace, signatureForVertex } from '../src/facade/topologyNaming'
@@ -376,6 +376,27 @@ test('persistence writes are serialized and continue after a failed write', asyn
   assert.equal(results[2].status, 'fulfilled')
 })
 
+test('project persistence broadcasts saved document versions across clients', async () => {
+  const writer = createSqliteProjectPersistence()
+  const observer = createSqliteProjectPersistence()
+  const notice = new Promise<{ documentId: string; documentVersion: number }>((resolve, reject) => {
+    const timer = setTimeout(() => reject(new Error('Expected cross-tab save notice.')), 250)
+    const unsubscribe = observer.subscribeExternalChanges((change) => {
+      clearTimeout(timer)
+      unsubscribe()
+      resolve(change)
+    })
+  })
+  const document = recomputeDocumentFixture()
+  const saved = await writer.save(document)
+  assert.equal(writer.capabilities().crossTabWriteLock, 'local-queue')
+  const received = await notice
+  assert.equal(received.documentId, saved.documentId)
+  assert.equal(received.documentVersion, saved.documentVersion)
+  await writer.dispose()
+  await observer.dispose()
+})
+
 test('autosave scheduler coalesces idle document changes and flushes the latest version', async () => {
   const savedVersions: number[] = []
   const scheduler = new ProjectAutosaveScheduler(async (document) => { savedVersions.push(document.version); return { documentId: document.id, documentVersion: document.version, persistedAt: Date.now(), mode: 'sqlite-memory' } }, 5)