feat(dev/lazy): inject lazy compilation runtime automatically by hyf0 · Pull Request #7816 · rolldown/rolldown

hyf0 · 2026-01-09T08:31:35Z

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hyf0 · 2026-01-09T08:31:48Z

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crates/rolldown/src/hmr/hmr_stage.rs

examples/lazy/src/async-lib-shared.js

Copilot

Pull request overview

This PR implements automatic runtime injection for lazy compilation, eliminating the need for users to manually unwrap lazy module exports. The plugin now automatically wraps all dynamic imports with a helper function that transparently unwraps the rolldown:exports promise for lazy modules while passing through regular modules unchanged.

Key changes:

New runtime_injector.rs module that uses oxc AST visitor to transform dynamic imports
Updated lazy_compilation_plugin.rs to register and implement transform_ast hook
Removed manual lazyMagic helper from example code, demonstrating the improved DX

Reviewed changes

Copilot reviewed 13 out of 14 changed files in this pull request and generated no comments.

Show a summary per file

File	Description
`crates/rolldown_plugin_lazy_compilation/src/runtime_injector.rs`	New module implementing AST visitor to transform dynamic imports and generate the unwrap helper function
`crates/rolldown_plugin_lazy_compilation/src/lazy_compilation_plugin.rs`	Added `transform_ast` hook implementation with directive prologue handling
`crates/rolldown_plugin_lazy_compilation/src/lib.rs`	Exports the new runtime_injector module
`crates/rolldown_plugin_lazy_compilation/Cargo.toml`	Added oxc dependency for AST manipulation
`examples/lazy/src/entry-a.js`	Removed manual `lazyMagic` helper, uses standard dynamic imports
`examples/lazy/src/async-entry-a.js`	Added shared module import, updated output formatting
`examples/lazy/src/async-entry-b.js`	Added shared module import, added DOM output
`examples/lazy/src/async-lib-a.js`	Updated string formatting for consistency
`examples/lazy/src/async-lib-b.js`	Updated string formatting for consistency
`examples/lazy/src/async-lib-shared.js`	New shared module to test lazy compilation with shared dependencies
`examples/lazy/lazy-compilation.md`	Comprehensive documentation updates explaining the automatic unwrapping mechanism
`packages/test-dev-server/src/dev-server.ts`	Added timing logs for initial build (acceptable for test utility)
`crates/rolldown/src/hmr/hmr_stage.rs`	Added debug println statement (should be removed or converted to proper logging)
`deny.toml`	Added advisory ignore for unmaintained bincode dependency
`Cargo.lock`	Updated with new oxc dependency

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github-actions · 2026-01-09T09:07:31Z

Benchmarks Rust

target: 01-07-fix_dev_lazy_should_include_imported_and_non-executed_modules_in_the_patch(d9615cd)
pr: 01-09-feat_dev_lazy_inject_lazy_compilation_runtime_automatically(1b63037)

group                                                        pr                                     target
-----                                                        --                                     ------
bundle/bundle@multi-duplicated-top-level-symbol              1.00     63.7±1.97ms        ? ?/sec    1.06     67.5±2.36ms        ? ?/sec
bundle/bundle@multi-duplicated-top-level-symbol-sourcemap    1.00     70.2±2.00ms        ? ?/sec    1.06     74.4±2.49ms        ? ?/sec
bundle/bundle@rome_ts                                        1.00    106.2±2.76ms        ? ?/sec    1.00    106.3±1.90ms        ? ?/sec
bundle/bundle@rome_ts-sourcemap                              1.00    117.1±2.23ms        ? ?/sec    1.02    119.2±2.69ms        ? ?/sec
bundle/bundle@threejs                                        1.00     38.0±0.87ms        ? ?/sec    1.02     38.7±2.21ms        ? ?/sec
bundle/bundle@threejs-sourcemap                              1.00     42.5±0.71ms        ? ?/sec    1.02     43.4±0.81ms        ? ?/sec
bundle/bundle@threejs10x                                     1.00    388.4±5.13ms        ? ?/sec    1.01    391.9±4.19ms        ? ?/sec
bundle/bundle@threejs10x-sourcemap                           1.00    448.4±7.58ms        ? ?/sec    1.01    454.3±5.27ms        ? ?/sec
scan/scan@rome_ts                                            1.00     83.6±1.82ms        ? ?/sec    1.04     87.0±1.82ms        ? ?/sec
scan/scan@threejs                                            1.00     28.6±1.66ms        ? ?/sec    1.01     28.9±0.58ms        ? ?/sec
scan/scan@threejs10x                                         1.00    292.1±4.82ms        ? ?/sec    1.02    298.5±5.21ms        ? ?/sec

hyf0 · 2026-01-09T11:10:55Z

Merge activity

Jan 9, 11:10 AM UTC: The merge label 'graphite: merge-when-ready' was detected. This PR will be added to the Graphite merge queue once it meets the requirements.
Jan 9, 12:08 PM UTC: hyf0 added this pull request to the Graphite merge queue.
Jan 9, 12:24 PM UTC: Merged by the Graphite merge queue.

netlify · 2026-01-09T12:15:35Z

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@shulaoda

## [1.0.0-beta.60] - 2026-01-14 ### 💥 BREAKING CHANGES - tsconfig: enable auto-discovery by default (#7817) by @shulaoda ### 🚀 Features - distinguish transformer diagnostics from parse errors (#7872) by @shulaoda - emit transformer warnings instead of ignoring them (#7850) by @shulaoda - node: add `output.codeSplitting` option and deprecate `output.advancedChunks` (#7855) by @hyf0 - nativeMagicString reset (#7828) by @IWANABETHATGUY - nativeMagicString lastChar (#7819) by @IWANABETHATGUY - dev/lazy: inject lazy compilation runtime automatically (#7816) by @hyf0 - nativeMagicString snip (#7818) by @IWANABETHATGUY - nativeMagicString construct with options (#7814) by @IWANABETHATGUY - nativeMagicString clone (#7813) by @IWANABETHATGUY - nativeMagicString `insert` (#7812) by @IWANABETHATGUY - nativeMagicString `slice` (#7807) by @IWANABETHATGUY - nativeMagicString trim methods (#7800) by @IWANABETHATGUY - make closeBundle hook receive the last error (#7278) by @Copilot ### 🐛 Bug Fixes - when package only contains export default, cjsDefault didn't resolve correctly (#7873) by @IWANABETHATGUY - inline __name calls for default exports (#7862) by @IWANABETHATGUY - improve variable renaming to avoid unnecessary shadowing in nested scopes (#7859) by @IWANABETHATGUY - use correct index when inserting keepNames statements during export default transformation (#7853) by @IWANABETHATGUY - transform non-static dynamic imports when `dynamicImportInCjs` is `false` (#7823) by @shulaoda - dev/lazy: should include imported and non-executed modules in the patch (#7815) by @hyf0 - set ExportsKind to Esm when json is none object literal (#7808) by @IWANABETHATGUY - nativeMagicString move api (#7796) by @IWANABETHATGUY - remove unnecessary exports after merging into commong and user defined entry (#7789) by @IWANABETHATGUY - use output.name instead of chunk.name in mixed export warning (#7788) by @Copilot ### 🚜 Refactor - generalize ParseError to OxcError with dynamic EventKind (#7868) by @shulaoda - rust: rename `advanced_chunks` to `manual_code_splitting` (#7856) by @hyf0 - string_wizard error hanlding (#7830) by @IWANABETHATGUY - remove `experimental.disableLiveBindings` option (#7820) by @sapphi-red - node/test: run fixture tests in concurrent (#7790) by @hyf0 - move ConfigExport and RolldownOptionsFunction types to define-config (#7799) by @shulaoda - cli: validate config after resolving and improve error message (#7798) by @shulaoda ### 📚 Documentation - rebrand (#7670) by @yyx990803 - fix incorrect default value for propertyReadSideEffects (#7847) by @Copilot - remove options pages and redirect to reference pages (#7834) by @sapphi-red - options: inline types to option property pages (#7831) by @sapphi-red - options: port checks.pluginTimings content from options page to reference page (#7832) by @sapphi-red - options: use `@linkcode` where possible (#7824) by @sapphi-red - options: port content from options page to reference page (#7822) by @sapphi-red - options: add descriptions for output options (#7821) by @sapphi-red - options: add description for input options (#7802) by @sapphi-red - options: add description for `checks.*` (#7801) by @sapphi-red - apis: add hook graph (#7671) by @sapphi-red ### 🧪 Testing - add all valid combination of chunk exports related test (#7851) by @IWANABETHATGUY - enable MagicString test after api return type alignment (#7797) by @IWANABETHATGUY - init magic-string test (#7794) by @IWANABETHATGUY ### ⚙️ Miscellaneous Tasks - vite-tests: configure git user for rebase operation (#7875) by @shulaoda - rolldown_binding: remove v3 native plugins (#7837) by @shulaoda - rolldown_binding: allow crate-type as lib (#7866) by @Brooooooklyn - README.md: adjust position and size of rolldown logo (#7861) by @hyf0 - deps: update test262 submodule for tests (#7857) by @sapphi-red - deps: update oxc to v0.108.0 (#7845) by @renovate[bot] - deps: update dependency oxlint to v1.39.0 (#7849) by @renovate[bot] - deps: update dependency oxfmt to ^0.24.0 (#7844) by @renovate[bot] - deps: update npm packages (#7841) by @renovate[bot] - deps: update rust crates (#7839) by @renovate[bot] - deps: update github-actions (#7840) by @renovate[bot] - use workspace edition for all crates (#7829) by @IWANABETHATGUY - deps: update dependency oxlint-tsgolint to v0.11.0 (#7827) by @renovate[bot] - deps: update napi to v3.8.2 (#7810) by @renovate[bot] - remove outdated snapshot files (#7806) by @shulaoda - deps: update crate-ci/typos action to v1.42.0 (#7792) by @renovate[bot] Co-authored-by: shulaoda <[email protected]>

github-actions bot assigned hyf0 Jan 9, 2026

hyf0 mentioned this pull request Jan 9, 2026

fix(dev/lazy): should include imported and non-executed modules in the patch #7815

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hyf0 marked this pull request as ready for review January 9, 2026 08:32

hyf0 requested review from Copilot and sapphi-red and removed request for Copilot January 9, 2026 08:32

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Copilot AI review requested due to automatic review settings January 9, 2026 08:47

hyf0 force-pushed the 01-09-feat_dev_lazy_inject_lazy_compilation_runtime_automatically branch from b57b300 to b555338 Compare January 9, 2026 08:47

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hyf0 force-pushed the 01-09-feat_dev_lazy_inject_lazy_compilation_runtime_automatically branch from b555338 to 1b63037 Compare January 9, 2026 08:51

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graphite-app bot changed the base branch from 01-07-fix_dev_lazy_should_include_imported_and_non-executed_modules_in_the_patch to graphite-base/7816 January 9, 2026 12:02

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graphite-app bot changed the base branch from graphite-base/7816 to main January 9, 2026 12:13

feat(dev/lazy): inject lazy compilation runtime automatically (#7816)

f923f68

graphite-app bot force-pushed the 01-09-feat_dev_lazy_inject_lazy_compilation_runtime_automatically branch from 1b63037 to f923f68 Compare January 9, 2026 12:14

graphite-app bot merged commit f923f68 into main Jan 9, 2026
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graphite-app bot deleted the 01-09-feat_dev_lazy_inject_lazy_compilation_runtime_automatically branch January 9, 2026 12:24

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This was referenced Jan 14, 2026

release: v1.0.0-beta.60 #7869

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release: v1.0.0-beta.60 #7877

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feat(dev/lazy): inject lazy compilation runtime automatically#7816

feat(dev/lazy): inject lazy compilation runtime automatically#7816
graphite-app[bot] merged 1 commit intomainfrom
01-09-feat_dev_lazy_inject_lazy_compilation_runtime_automatically

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Benchmarks Rust

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