[DCE] Fix var hoisting #169
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kangax
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Sep 29, 2016
| @@ -895,4 +895,10 @@ module.exports = ({ types: t, traverse }) => { | |||
| }; | |||
| } | |||
| } | |||
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| // things that are hoisted | |||
| function canExistAfterCompletion(path) { | |||
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So basically anything that doesn't conform to TDZ? What about function?
a = 1;
return a;
function a() { }There was a problem hiding this comment.
That test is already covered in name=should be fine with fun decl after return if that's what you meant.
Fix bug where var declarations after compleition statements are deadcode eliminated - vars are hoisted in JS and need to be preserved like function declarations (Close #167)
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One other option to handle this will be to hoist var declarations as one of the first plugins. But @amasad had concerns with the hoisting effect on gzip in #52 . So this approach is okay IMO.
a = 1; return a; var a;could not be reduced toreturn 1because we don't have the flow of control in the program - this is here in babel - babel/babel#4420