feat(unstable): support TC39 import defer proposal#32360
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bartlomieju merged 12 commits intodenoland:mainfrom Apr 29, 2026
Merged
feat(unstable): support TC39 import defer proposal#32360bartlomieju merged 12 commits intodenoland:mainfrom
bartlomieju merged 12 commits intodenoland:mainfrom
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Adds support for the TC39 "Deferred Module Evaluation" proposal (https://github.com/tc39/proposal-defer-import-eval, Stage 3). Changes: - Enable V8 `--js-defer-import-eval` flag for parser/runtime support - Separate `ModuleImportPhase::Defer` handling from `Evaluation` phase: deferred modules are instantiated but not evaluated, letting V8 create a deferred namespace that triggers evaluation on first property access - Add integration test validating deferred evaluation semantics Ported from denoland/deno_core#1280 Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
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devsnek
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Waiting on v8/v8@f2016e1 in V8 14.7. |
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Upgrade rusty_v8 to 147.3.0 which includes the Module::EvaluateForImportDefer and GetModuleNamespace with phase APIs needed for dynamic import.defer() support. Fix merge conflict in map.rs: restore separate Defer arm in dynamic import handling (must NOT call dynamic_import_module_evaluate since defer imports should not be evaluated until namespace access). Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
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Point to local deno_graph (with ImportDefer variants) and deno_doc. Add ImportDefer handling to unfurl.rs. Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
Use the new V8 Module::evaluate_for_import_defer API for dynamic import.defer() to properly gather async transitive dependencies before resolving. Get the deferred namespace via get_module_namespace_with_phase (kDefer) so V8 creates a namespace that triggers evaluation on first property access. Handles three promise states: - Fulfilled: all async deps ready, resolve immediately with deferred ns - Rejected: propagate error to dynamic import reject - Pending: store for later resolution via pending_dyn_mod_evaluations Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
- Filter TS18060 diagnostic ("Deferred imports are only supported when
module is esnext or preserve") since Deno handles module resolution
natively and supports import defer.
- Add test for running import defer from TypeScript files.
- Add test for type-checking import defer TypeScript files.
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
Replace local path overrides with published crate versions that include import defer support. Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
…o feat/import-defer-eval
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This commit adds an experimental support for
import defer ...syntax,for https://github.com/tc39/proposal-defer-import-eval proposal.
Closes #30053