Austaras 5dbbbea2ef fix(es/minifier): Mark all function params as potential property mutation (#7409) ... **Description:** This issue is more severe than I originally thought. It raises not in array indexing, but in function calls and property mutation. We should treat all function arguments as potentially be property mutated, otherwise following example ```js class A { a = 1 toString() { return this.a } } const a = new A() function foo(x) { x.a++ } const b = a + 1 foo(a) console.log(b) ``` would be error(It should log 2, but logs 3 after compress). As the result, massive regressions is unavoidable, since some of these optimizations may indeed cause error. Part of them can be mitigated with following optimization -- allow inline of ident even if its original value is mutated. Consider ```js export function foo(x) { const y = x x.a = 1 y.b = 2 } ``` If x is a primitive value, all mutations to its properties are ignored; if x is a object, then y refers to the same object no matter what mutation is performed. And there's still room for more, currently following code ```js export function foo(x) { const y = Math.floor(x); g(y); } ``` But I'd rather do it in a separate PR. **Related issue:** - Closes #7402.		2023-05-18 01:19:17 +00:00
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input.js	refactor(es/minifier): Make rust-analyzer fast, really (#4746)	2022-05-23 16:16:05 +09:00
output.js	fix(es/minifier): Mark all function params as potential property mutation (#7409)	2023-05-18 01:19:17 +00:00