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kotlinlang

Is there an issue that describes the reasoning behind `-Xenable-extension-functions-in-externals` (and maybe why it's off by default)?

Found <https://github.com/JetBrains/kotlin/commit/83c1a119eeadbe431f925b1fcbb5af1fb0c90391>
But yeah did not get how it came up, maybe <@UAG4QQZB6> remembers

There was a demand from one of JetBrains project.
The reason is that it can be ambiguity what we understand with “extension functions in externals”, because of dynamic nature of `this` in JavaScript. That’s why it is not default
There can be 2 different cases
1. It is indeed replacement of `this` , for example you have class A in js, and function `foo`, but `this` in the function is not `A` but something different
2. Just like on JVM it is another argument in a method. So compiler key enables exactly this option.

Thank you! Just tried it and it can be useful indeed