Leading underscore not trimmed in object keys

[azz]

Forwarding from prettier/prettier#2143.

Input:

obj = {                                                                               
  '__': 42 
}

Output:

obj = {                                                                               
  '___': 42 
}

Looks the same as #296

[soda0289]

Thanks for the report. I wonder if there are any other places this happens. Pretty much anywhere we have an identifier, that's not an identifier node type, we need to escape the value.

[azz]

Curious why TS needs to "escape" it in the first place?

[JamesHenry]

@azz This is the original issue we reported to them microsoft/TypeScript#14013, you can see their response on there

[azz]

Thanks! Seems like it could have been avoided with a good old hasOwnProperty check or Object.create(null)? 😉