IndexMigrator: fix non blocking migration wrapper promise rejection (#…

…77018) (#77092)

* fix transformNonBlocking

* add test for indexMigrator

src/core/server/saved_objects/migrations/core/index_migrator.test.ts

@@ -369,6 +369,30 @@ describe('IndexMigrator', () => {
  ],
  });
  });
+
+ test('rejects when the migration function throws an error', async () => {
+ const { client } = testOpts;
+ const migrateDoc = jest.fn((doc: SavedObjectUnsanitizedDoc) => {
+ throw new Error('error migrating document');
+ });
+
+ testOpts.documentMigrator = {
+ migrationVersion: { foo: '1.2.3' },
+ migrate: migrateDoc,
+ };
+
+ withIndex(client, {
+ numOutOfDate: 1,
+ docs: [
+ [{ _id: 'foo:1', _source: { type: 'foo', foo: { name: 'Bar' } } }],
+ [{ _id: 'foo:2', _source: { type: 'foo', foo: { name: 'Baz' } } }],
+ ],
+ });
+
+ await expect(new IndexMigrator(testOpts).migrate()).rejects.toThrowErrorMatchingInlineSnapshot(
+ `"error migrating document"`
+ );
+ });
 });
 
 function withIndex(

src/core/server/saved_objects/migrations/core/migrate_raw_docs.test.ts

@@ -90,4 +90,18 @@ describe('migrateRawDocs', () => {
 
  expect(logger.error).toBeCalledTimes(1);
  });
+
+ test('rejects when the transform function throws an error', async () => {
+ const transform = jest.fn<any, any>((doc: any) => {
+ throw new Error('error during transform');
+ });
+ await expect(
+ migrateRawDocs(
+ new SavedObjectsSerializer(new SavedObjectTypeRegistry()),
+ transform,
+ [{ _id: 'a:b', _source: { type: 'a', a: { name: 'AAA' } } }],
+ createSavedObjectsMigrationLoggerMock()
+ )
+ ).rejects.toThrowErrorMatchingInlineSnapshot(`"error during transform"`);
+ });
 });

src/core/server/saved_objects/migrations/core/migrate_raw_docs.ts

@@ -78,10 +78,14 @@ function transformNonBlocking(
 ): (doc: SavedObjectUnsanitizedDoc) => Promise<SavedObjectUnsanitizedDoc> {
  // promises aren't enough to unblock the event loop
  return (doc: SavedObjectUnsanitizedDoc) =>
- new Promise((resolve) => {
+ new Promise((resolve, reject) => {
  // set immediate is though
  setImmediate(() => {
- resolve(transform(doc));
+ try {
+ resolve(transform(doc));
+ } catch (e) {
+ reject(e);
+ }
  });
  });
 }