I think you are conflating the report location with the behavior that it removes comments. Fixers removing comments is a pervasive issue in linters because, well, comments aren't part of the AST so it's hard to re-position them after changing the AST. Many other rules suffer from the same issue, such as #4730, but I don't see a general way to help.

On the other hand, we absolutely want the report location to be as specific as possible. This rule checks each embedded expression one by one, so it should definitely report those expressions, not the template as a whole.

To be clear, I'm proposing changing

`use${'less'}template${'expressions'}`
      ^^^^^^           ^^^^^^^^^^^^^
// to this
`use${'less'}template${'expressions'}`
    ^^^^^^^^^        ^^^^^^^^^^^^^^^^
// NOT this
`use${'less'}template${'expressions'}`
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

But yeah, as long as we're talking about the same thing, if you think trying to include the ${} in the report is misguided, feel free to close! Not very important one way or another.

Ahh—yeah that makes sense! I like that better. Not sure if it's easy to implement, considering those are not AST nodes, but this behavior is definitely more ideal.

Ezpz 😊 the report API can take arbitrary loc, which we have in hand anyway for the autofixes

The tokens should be readily available to seek backwards/forwards from the expression - so shouldn't be too bad.

My one concern would be this case:

`use${
  'less'
}template${
  'expressions'
}`

Which is fairly common in prettier formatted code.
Which would change the errors in a negative/noisy way IMO

// before
`use${
  'less'
  ^^^^^^
}template${
  'expressions'
  ^^^^^^^^^^^^^
}`

// after
`use${
    ^^
  'less'
^^^^^^^^
}template${
^        ^^
  'expressions'
^^^^^^^^^^^^^^^
}`
^

My one concern would be this case:

`use${
  'less'
}template${
  'expressions'
}`

Which is fairly common in prettier formatted code.
Which would change the errors in a negative/noisy way IMO

// before
`use${
  'less'
  ^^^^^^
}template${
  'expressions'
  ^^^^^^^^^^^^^
}`

// after
`use${
    ^^
  'less'
^^^^^^^^
}template${
^        ^^
  'expressions'
^^^^^^^^^^^^^^^
}`
^

Having played around with this in a local playground, that's actually exactly what I liked about it a lot, because the error has nothing to do with the expression 'less' itself, it has to do with how it's used in the context of the adjacent lines, and that becomes more clear IMO. But I recognize that that is purely a personal preference.

I also think this is fine, since the fixer modifies the embedding, not the expression.

I'm also not sure if ${ is a token by itself—each template span should be a token, so we probably still have to do start: getPreviousToken().end - 2, but that's still fine if it's robust enough.