fix: harden persistence tiers and opfs durability

tests/opfs-write-serialization.mjs

@@ -0,0 +1,133 @@
+import assert from "node:assert/strict";
+
+import {
+  BME_GRAPH_LOCAL_STORAGE_MODE_OPFS_PRIMARY,
+  OpfsGraphStore,
+} from "../sync/bme-opfs-store.js";
+import { createMemoryOpfsRoot } from "./helpers/memory-opfs.mjs";
+
+async function testCommitDeltaAndPatchMetaSerialize() {
+  const rootDirectory = createMemoryOpfsRoot({
+    writeDelayMs: 5,
+  });
+  const store = new OpfsGraphStore("chat-opfs-serialize-meta", {
+    rootDirectoryFactory: async () => rootDirectory,
+    storeMode: BME_GRAPH_LOCAL_STORAGE_MODE_OPFS_PRIMARY,
+  });
+  await store.open();
+
+  await store.importSnapshot(
+    {
+      meta: {
+        revision: 1,
+        lastBackupFilename: "",
+      },
+      state: {
+        lastProcessedFloor: 0,
+        extractionCount: 0,
+      },
+      nodes: [],
+      edges: [],
+      tombstones: [],
+    },
+    {
+      mode: "replace",
+      preserveRevision: true,
+    },
+  );
+
+  await Promise.all([
+    store.commitDelta(
+      {
+        upsertNodes: [
+          {
+            id: "node-1",
+            type: "event",
+            fields: {
+              title: "serialized",
+            },
+            archived: false,
+            updatedAt: 100,
+          },
+        ],
+      },
+      {
+        reason: "serialized-node",
+      },
+    ),
+    store.patchMeta({
+      lastBackupFilename: "backup-a.json",
+      lastProcessedFloor: 7,
+      extractionCount: 3,
+    }),
+  ]);
+
+  const snapshot = await store.exportSnapshot();
+  assert.equal(snapshot.nodes.length, 1);
+  assert.equal(snapshot.nodes[0]?.id, "node-1");
+  assert.equal(snapshot.meta.lastBackupFilename, "backup-a.json");
+  assert.equal(snapshot.state.lastProcessedFloor, 7);
+  assert.equal(snapshot.state.extractionCount, 3);
+}
+
+async function testImportSnapshotAndClearAllSerialize() {
+  const rootDirectory = createMemoryOpfsRoot({
+    writeDelayMs: 5,
+  });
+  const store = new OpfsGraphStore("chat-opfs-serialize-clear", {
+    rootDirectoryFactory: async () => rootDirectory,
+    storeMode: BME_GRAPH_LOCAL_STORAGE_MODE_OPFS_PRIMARY,
+  });
+  await store.open();
+
+  await store.importSnapshot(
+    {
+      meta: { revision: 2 },
+      state: { lastProcessedFloor: 5, extractionCount: 2 },
+      nodes: [
+        {
+          id: "seed-node",
+          type: "event",
+          fields: { title: "seed" },
+          archived: false,
+          updatedAt: 1,
+        },
+      ],
+      edges: [],
+      tombstones: [],
+    },
+    { mode: "replace", preserveRevision: true },
+  );
+
+  await Promise.all([
+    store.clearAll(),
+    store.importSnapshot(
+      {
+        meta: { revision: 4 },
+        state: { lastProcessedFloor: 9, extractionCount: 4 },
+        nodes: [
+          {
+            id: "after-clear-node",
+            type: "fact",
+            fields: { title: "after-clear" },
+            archived: false,
+            updatedAt: 2,
+          },
+        ],
+        edges: [],
+        tombstones: [],
+      },
+      { mode: "replace", preserveRevision: true },
+    ),
+  ]);
+
+  const snapshot = await store.exportSnapshot();
+  assert.equal(snapshot.nodes.length, 1);
+  assert.equal(snapshot.nodes[0]?.id, "after-clear-node");
+  assert.equal(snapshot.state.lastProcessedFloor, 9);
+  assert.equal(snapshot.state.extractionCount, 4);
+}
+
+await testCommitDeltaAndPatchMetaSerialize();
+await testImportSnapshotAndClearAllSerialize();
+console.log("opfs-write-serialization tests passed");