feat(mf): add async startup promise gating for entrypoints #11899
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ScriptedAlchemy
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Pull Request Overview
This PR adds support for async startup promises across different module formats and fixes duplicate exports in module federation async startup scenarios.
- Adds async startup promise support for multiple module formats
- Fixes duplicate export issues in module federation async startup runtime
- Updates test snapshots to reflect webpack runtime changes
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tests/rspack-test/serialCases/container-1-5/1-container-full/index.js
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❌ Size increased by 11.38KB from 47.87MB to 47.88MB (⬆️0.02%) |
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ustr-fxhash is a valid transitive dependency from rspack_cacheable that is used by the crate's dependencies. Add it to cargo-shear's ignored list to resolve CI dependency check failure.
Prevents wrapping container/remote chunks in Promise.resolve() when mfAsyncStartup is enabled. Only host entry chunks that need async startup should be wrapped, otherwise remote module.exports becomes a promise instead of the synchronous container object that consumers expect. Also updates API extractor output for experiments.mfAsyncStartup field.
- Update Defaults.test.js to delete deferImport and topLevelAwait from both configs - Update runtime modules count from 12→3 in stats snapshots (correct behavior after P0 fix) - Remove fullHash warning expectation (no longer emitted after fix) - Delete PROPOSAL-async-federation-startup.md All changes align with main branch expectations after properly implementing mf_async_startup.
The plugin macro system uses these structs and methods dynamically through trait implementations, but Rust's static analysis cannot detect this usage. Added #[allow(dead_code)] attributes to suppress false positive warnings in CI's deny warnings mode. Also fixed clippy warning about unnecessary reference in runtime_chunk_map.get().
The mf_async_startup field was added to the Experiments struct, so the defaults snapshot needs to include it.
The plugin hook macros dynamically register callback functions at runtime, which Rust's static analysis cannot detect. Using module-level #![allow(dead_code)] is the proper solution for macro-based callback systems where code usage is determined at runtime rather than compile-time.
Aligned test files with main branch to fix 5 test failures: - Restored Defaults.test.js (removed extra deferImport deletion) - Restored base.js snapshot (removed mfAsyncStartup from inline snapshot) The mf_async_startup field is correctly configured with IGNORE comments in defaults.ts, allowing it to exist in the codebase while being excluded from test comparisons. 🤖 Generated with [Claude Code](https://claude.com/claude-code) Co-Authored-By: Claude <[email protected]>
Added mfAsyncStartup: false to defaultsCases snapshot since it's now a valid experiment default on this branch. The IGNORE mechanism only applies to webpack alignment tests, not defaultsCases inline snapshots. 🤖 Generated with [Claude Code](https://claude.com/claude-code) Co-Authored-By: Claude <[email protected]>
- Remove debug environment variable and eprintln! logging - Replace fragile variable name matching with robust package path matching - Change from matching "__module_federation_bundler_runtime__" variable name to matching "@module-federation/webpack-bundler-runtime" package path - This improves maintainability and reduces coupling to generated code The package path matching is more stable as it identifies the actual module being imported rather than relying on a specific variable naming convention that could change. 🤖 Generated with [Claude Code](https://claude.com/claude-code) Co-Authored-By: Claude <[email protected]>
These CSS package.json formatting changes are unrelated to the Module Federation async startup feature and should match main branch. 🤖 Generated with [Claude Code](https://claude.com/claude-code) Co-Authored-By: Claude <[email protected]>
Only apply async startup runtime modules when mf_async_startup experiment is explicitly enabled. This prevents adding extra runtime modules to non-MF builds. Fixes test failures where stats snapshots showed 12 runtime modules instead of 3 for regular (non-MF) builds.
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| export interface RawModuleFederationRuntimePluginOptions { | ||
| entryRuntime?: string | undefined | ||
| experiments?: RawModuleFederationRuntimeExperimentsOptions | ||
| asyncStartup?: boolean |
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duplicate with experiments.asyncStartup?
| .into(), | ||
| ); | ||
| if has_expose_entry | ||
| && runtime_requirements.contains(RuntimeGlobals::ASYNC_FEDERATION_STARTUP) |
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The mf specific logic shouldn't place at here
| // In async federation startup mode, STARTUP may return a Promise even when the entry module is | ||
| // sync (because it awaits federation init). Ensure we await the startup result before reading | ||
| // export fields so module outputs like MF containers still export live functions (get/init). | ||
| if is_async || runtime_requirements.contains(RuntimeGlobals::ASYNC_FEDERATION_STARTUP) { |
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Can we just reuse the is_async? If user enable the asyncStartup, then we mark the mf entry as an async module
| runtime_requirements.insert(RuntimeGlobals::ON_CHUNKS_LOADED); | ||
| // When async federation startup is requested, STARTUP_ENTRYPOINT will be present and | ||
| // the MF wrapper handles startup; avoid adding ON_CHUNKS_LOADED in that case. | ||
| if !runtime_requirements.contains(RuntimeGlobals::ASYNC_FEDERATION_STARTUP) { |
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Here is the same, I don't want the mf specific logic affects rspack_plugin_runtime and rspack_plugin_javascript
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Summary
experiments.asyncStartupsupport for Module Federation by embedding federation runtime deps and exposing a guarded async startup hook.get/initexports) while still running the embedded federation runtime setup.runtimeChunk: "single"/multi-runtime.Notes
experiments.asyncStartupis disabled.Tests