[eas-cli] Pre-warm bsdiff patches against top-K base and embedded updates

CHANGELOG.md

@@ -13,6 +13,8 @@ This is the log of notable changes to EAS CLI and related packages.
 
 ### 🐛 Bug fixes
 
+- [eas-cli] Pre-warm bsdiff update patches against the top recent updates and the embedded bundles on a branch, rather than only the second-most-recent update, so more devices are served a diffed patch instead of the full un-diffed update while the on-demand diff computes. ([#3869](https://github.com/expo/eas-cli/pull/3869) by [@jc-expo](https://github.com/jc-expo))
+
 ### 🧹 Chores
 
 - [eas-cli] Simplify 2FA now that SMS is no longer supported. ([#3859](https://github.com/expo/eas-cli/pull/3859) by [@wschurman](https://github.com/wschurman))

packages/eas-cli/src/update/__tests__/utils-test.ts

@@ -1,4 +1,27 @@
-import { getPlatformsForGroup, truncateString } from '../utils';
+import { instance, mock } from 'ts-mockito';
+
+import { ExpoGraphqlClient } from '../../commandUtils/context/contextUtils/createGraphqlClient';
+import fetch from '../../fetch';
+import { UpdatePublishMutation } from '../../graphql/generated';
+import { AssetQuery } from '../../graphql/queries/AssetQuery';
+import { BranchQuery } from '../../graphql/queries/BranchQuery';
+import { ChannelQuery } from '../../graphql/queries/ChannelQuery';
+import { EmbeddedUpdateQuery } from '../../graphql/queries/EmbeddedUpdateQuery';
+import { getPlatformsForGroup, prewarmDiffingAsync, truncateString } from '../utils';
+
+jest.mock('../../fetch');
+jest.mock('../../graphql/queries/AssetQuery');
+jest.mock('../../graphql/queries/BranchQuery');
+jest.mock('../../graphql/queries/ChannelQuery');
+jest.mock('../../graphql/queries/EmbeddedUpdateQuery');
+
+// A standard "always true" branch mapping that routes the channel to the given branch.
+function branchMappingForBranch(branchId: string): string {
+  return JSON.stringify({
+    version: 0,
+    data: [{ branchId, branchMappingLogic: 'true' }],
+  });
+}
 
 describe('update utility functions', () => {
   describe(truncateString, () => {
@@ -27,4 +50,129 @@ describe('update utility functions', () => {
       expect(getPlatformsForGroup(input)).toEqual(`N/A`);
     });
   });
+
+  describe(prewarmDiffingAsync, () => {
+    const updateStub: UpdatePublishMutation['updateBranch']['publishUpdateGroups'][number] = {
+      id: 'new-update-id',
+      group: 'group-1234',
+      createdAt: '2026-01-01T00:00:00Z',
+      runtimeVersion: '1.0.0',
+      platform: 'ios',
+      manifestFragment: JSON.stringify({ launchAsset: { storageKey: 'launch-key' } }),
+      isRollBackToEmbedded: false,
+      manifestPermalink: 'https://expo.dev/fake/manifest/link',
+      isGitWorkingTreeDirty: false,
+      branch: { id: 'branch-1234', name: 'production' },
+    };
+
+    beforeEach(() => {
+      jest.resetAllMocks();
+      jest.mocked(fetch).mockResolvedValue({} as any);
+    });
+
+    it('warms the top-K recent updates and the embedded bundle', async () => {
+      const graphqlClient = instance(mock<ExpoGraphqlClient>());
+      jest.mocked(BranchQuery.getUpdateIdsOnBranchAsync).mockResolvedValue(['r1', 'r2']);
+      jest
+        .mocked(AssetQuery.getSignedUrlsAsync)
+        .mockResolvedValue([{ storageKey: 'launch-key', url: 'https://cdn/asset', headers: {} }]);
+      jest.mocked(ChannelQuery.viewUpdateChannelsBasicInfoPaginatedOnAppAsync).mockResolvedValue({
+        edges: [
+          {
+            node: {
+              id: 'channel-1',
+              name: 'production',
+              branchMapping: branchMappingForBranch('branch-1234'),
+            },
+          },
+        ],
+      } as any);
+      jest
+        .mocked(EmbeddedUpdateQuery.viewPaginatedAsync)
+        .mockResolvedValue({ edges: [{ cursor: 'c0', node: { id: 'e1' } }] } as any);
+
+      const warmed = await prewarmDiffingAsync(graphqlClient, 'app-id', [updateStub]);
+
+      // The embedded bundle diffs against itself; recent updates fall back to the first embedded id.
+      expect(warmed).toEqual([
+        { requestedUpdateId: 'new-update-id', currentUpdateId: 'e1', embeddedUpdateId: 'e1' },
+        { requestedUpdateId: 'new-update-id', currentUpdateId: 'r1', embeddedUpdateId: 'e1' },
+        { requestedUpdateId: 'new-update-id', currentUpdateId: 'r2', embeddedUpdateId: 'e1' },
+      ]);
+      // Embedded bundles are restricted server-side to the channel that routes to the branch.
+      expect(
+        jest.mocked(EmbeddedUpdateQuery.viewPaginatedAsync).mock.calls.map(call => call[1].filter)
+      ).toContainEqual(expect.objectContaining({ channel: 'production' }));
+    });
+
+    it('only pre-warms embedded bundles for channels whose branch mapping routes to the published branch', async () => {
+      const graphqlClient = instance(mock<ExpoGraphqlClient>());
+      jest.mocked(BranchQuery.getUpdateIdsOnBranchAsync).mockResolvedValue(['r1']);
+      jest
+        .mocked(AssetQuery.getSignedUrlsAsync)
+        .mockResolvedValue([{ storageKey: 'launch-key', url: 'https://cdn/asset', headers: {} }]);
+      // 'production' routes to the published branch (branch-1234); 'staging' routes elsewhere.
+      jest.mocked(ChannelQuery.viewUpdateChannelsBasicInfoPaginatedOnAppAsync).mockResolvedValue({
+        edges: [
+          {
+            node: {
+              id: 'channel-prod',
+              name: 'production',
+              branchMapping: branchMappingForBranch('branch-1234'),
+            },
+          },
+          {
+            node: {
+              id: 'channel-staging',
+              name: 'staging',
+              branchMapping: branchMappingForBranch('other-branch'),
+            },
+          },
+        ],
+      } as any);
+      jest
+        .mocked(EmbeddedUpdateQuery.viewPaginatedAsync)
+        .mockResolvedValue({ edges: [{ cursor: 'c0', node: { id: 'e1' } }] } as any);
+
+      await prewarmDiffingAsync(graphqlClient, 'app-id', [updateStub]);
+
+      // Only the eligible 'production' channel is queried — never 'staging'.
+      expect(EmbeddedUpdateQuery.viewPaginatedAsync).toHaveBeenCalledTimes(1);
+      expect(
+        jest.mocked(EmbeddedUpdateQuery.viewPaginatedAsync).mock.calls.map(call => call[1].filter)
+      ).toEqual([expect.objectContaining({ channel: 'production' })]);
+    });
+
+    it('is best-effort: swallows errors and resolves to an empty list', async () => {
+      const graphqlClient = instance(mock<ExpoGraphqlClient>());
+      jest.mocked(BranchQuery.getUpdateIdsOnBranchAsync).mockRejectedValue(new Error('boom'));
+
+      await expect(prewarmDiffingAsync(graphqlClient, 'app-id', [updateStub])).resolves.toEqual([]);
+    });
+
+    it('returns empty when there are no recent updates on the branch', async () => {
+      const graphqlClient = instance(mock<ExpoGraphqlClient>());
+      jest.mocked(BranchQuery.getUpdateIdsOnBranchAsync).mockResolvedValue([]);
+
+      await expect(prewarmDiffingAsync(graphqlClient, 'app-id', [updateStub])).resolves.toEqual([]);
+    });
+
+    it('returns empty when there is no signed launch asset URL', async () => {
+      const graphqlClient = instance(mock<ExpoGraphqlClient>());
+      jest.mocked(BranchQuery.getUpdateIdsOnBranchAsync).mockResolvedValue(['r1']);
+      jest.mocked(AssetQuery.getSignedUrlsAsync).mockResolvedValue([]);
+
+      await expect(prewarmDiffingAsync(graphqlClient, 'app-id', [updateStub])).resolves.toEqual([]);
+    });
+
+    it('skips updates with no launch asset in the manifest', async () => {
+      const graphqlClient = instance(mock<ExpoGraphqlClient>());
+
+      await expect(
+        prewarmDiffingAsync(graphqlClient, 'app-id', [
+          { ...updateStub, manifestFragment: JSON.stringify({}) },
+        ])
+      ).resolves.toEqual([]);
+    });
+  });
 });