fix(collectionfactory): isolate collection caching per database and add easy store replace semantics

test/test.collectionfactory.ts

@@ -0,0 +1,70 @@
+import { tap, expect } from '@git.zone/tstest/tapbundle';
+import * as smartmongo from '@push.rocks/smartmongo';
+import * as smartdata from '../ts/index.js';
+
+/**
+ * Regression tests for:
+ *
+ *  1. CollectionFactory per-db cache (previously keyed by class name
+ *     alone, which made two SmartdataDb instances share a single
+ *     collection bound to whichever db happened to request it first).
+ *  2. EasyStore.replace() — new atomic-replace method that clears keys
+ *     not present in the new object. EasyStore.writeAll() still merges
+ *     for backward compatibility.
+ */
+
+let smartmongoInstance: smartmongo.SmartMongo;
+let dbA: smartdata.SmartdataDb;
+let dbB: smartdata.SmartdataDb;
+
+tap.test('setup: two dbs against the same replica set', async () => {
+  smartmongoInstance = await smartmongo.SmartMongo.createAndStart();
+  const desc = await smartmongoInstance.getMongoDescriptor();
+  dbA = new smartdata.SmartdataDb({ ...desc, mongoDbName: 'cf_test_a' });
+  dbB = new smartdata.SmartdataDb({ ...desc, mongoDbName: 'cf_test_b' });
+  await dbA.init();
+  await dbB.init();
+});
+
+tap.test('CollectionFactory: same class name in two dbs yields two collections', async () => {
+  const easyA = await dbA.createEasyStore<{ marker: string }>('shared');
+  const easyB = await dbB.createEasyStore<{ marker: string }>('shared');
+  await easyA.writeKey('marker', 'A');
+  await easyB.writeKey('marker', 'B');
+  const fromA = await easyA.readKey('marker');
+  const fromB = await easyB.readKey('marker');
+  expect(fromA).toEqual('A');
+  // Under the old singleton bug, this would be 'A' because the second
+  // createEasyStore() call would receive the collection bound to dbA.
+  expect(fromB).toEqual('B');
+});
+
+tap.test('EasyStore.replace: drops keys not present in the new object', async () => {
+  const store = await dbA.createEasyStore<{ a?: string; b?: string }>('replace_test');
+  await store.writeKey('a', '1');
+  await store.writeKey('b', '2');
+  expect(await store.readKey('a')).toEqual('1');
+  expect(await store.readKey('b')).toEqual('2');
+  await store.replace({ a: 'only-a' });
+  expect(await store.readKey('a')).toEqual('only-a');
+  // `b` must be gone — this is the whole point of replace() over writeAll().
+  expect(await store.readKey('b')).toBeUndefined();
+});
+
+tap.test('EasyStore.writeAll: still merges (back-compat)', async () => {
+  const store = await dbA.createEasyStore<{ a?: string; b?: string }>('merge_test');
+  await store.writeAll({ a: '1' });
+  await store.writeAll({ b: '2' });
+  expect(await store.readKey('a')).toEqual('1');
+  expect(await store.readKey('b')).toEqual('2');
+});
+
+tap.test('teardown', async () => {
+  await dbA.mongoDb.dropDatabase();
+  await dbB.mongoDb.dropDatabase();
+  await dbA.close();
+  await dbB.close();
+  await smartmongoInstance.stop();
+});
+
+export default tap.start();