fix(minifier): preserve var inside catch with same-named parameter#21037
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gthb wants to merge 1 commit intooxc-project:mainfrom
Open
fix(minifier): preserve var inside catch with same-named parameter#21037gthb wants to merge 1 commit intooxc-project:mainfrom
var inside catch with same-named parameter#21037gthb wants to merge 1 commit intooxc-project:mainfrom
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When `var e` appears inside `catch (e)`, the `var` hoists a declaration to function scope while the catch parameter creates a separate catch-scoped binding. The minifier was incorrectly: 1. Inlining the var's init value into subsequent expressions and removing the var declarator, losing the function-scoped hoisting effect. 2. Removing the catch parameter when it appeared "unused", which changes which binding `var e = value` assigns to. Fix 1: in `substitute_single_use_symbol_in_expression_from_declarators`, block name-based inlining when the var's symbol has the `CatchVariable` flag. Fix 2: in `substitute_catch_clause`, check whether the catch body contains a `var` with the same name as the catch parameter before removing it. Fixes oxc-project#17307
Author
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Used Claude for an initial draft, then reviewed and iterated. |
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What
Fix bugs involving
varin catch-clauses. Whenvar eappears insidecatch (e), thevarhoists a declaration to function scope while the catch parameter creates a separate catch-scoped binding. The minifier was incorrectly:Inlining the var's init value into subsequent expressions and removing the var declarator, losing the function-scoped hoisting effect.
Removing the catch parameter when it appeared "unused", which changes which binding
var e = valueassigns to.Fixes #17307
How
In
substitute_single_use_symbol_in_expression_from_declarators, block name-based inlining when the var's symbol has theCatchVariableflag.In
substitute_catch_clause, check whether the catch body contains avarwith the same name as the catch parameter, before removing it.