Call register_assignment_scope() in visit_export_default_expr() and visit_export_default_decl()#94581
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Call register_assignment_scope() in visit_export_default_expr() and visit_export_default_decl()#94581sampoder wants to merge 1 commit into
register_assignment_scope() in visit_export_default_expr() and visit_export_default_decl()#94581sampoder wants to merge 1 commit into
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Failing test suitesCommit: ab16b36 | About building and testing Next.js
Expand output● app dir - metadata static routes cache › should generate different content after replace the static metadata file Other failing CI jobs |
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Can we add a test case for that? Or does this just unblock some future change? |
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…nd `visit_export_default_decl()`
Registering an assignment scope for the synthetic default-export binding marks
it as constant-after-eval, so codegen can emit `export default <expr>` as a
plain value ("default", 0, ...) instead of a live getter arrow (() => ...) for
non-circuit-breaker modules. This avoids an arrow closure per default export.
Adds a snapshot test covering the value-form codegen.
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Added a snapshot test that demonstrates it! |
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Talked IRL, we found that calling this in
visit_export_default_expr()cut down themodule-costbenchmark on ESM execution by about 10ms (approx. 35%).Doing this unlocks a codegen optimization to avoid arrow functions, this special case was needed to support
export default ...which is a kind of declaration all on its own.