[Bug]: Numeric separators broken

[austindonisan]

💻

• Would you like to work on a fix?

How are you using Babel?

Other (Next.js, Gatsby, vue-cli, ...)

Input code

1_1

Configuration file name

No response

Configuration

No response

Current and expected behavior

Currently throws error:

/repl.jsx: A numeric separator is only allowed between two digits. (1:1)

> 1 | 1_1
    |  ^

Expected output:

"use strict";

11;

Environment

Babel REPL version 7.17.8

Possible solution

No response

Additional context

Works in 7.17.6, broken in 7.17.7

I'm guessing #14338 broke it

[babel-bot]

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[nicolo-ribaudo]

Wow, I'm surprised our tests didn't prevent us from breaking so badly.

[nicolo-ribaudo]

I can reproduce this on the REPL, but not locally 🤔

@austindonisan Do you have an example outside of the repl?

[nicolo-ribaudo]

Ok, I can reproduce the bug. It only affects @babel/standalone.