Manual copying of contents on firefox introduces newlines

[jackaperkins]

Using firefox on windows 10, manually copying text includes many newline characters causing code to be ruined when pasting. This renders some code in the wild totally unusable. I understand there is a copy (clipboard) button but it's common for people like myself to copy a few lines at a time to test things out.

Example code where this was tested:
https://twoslash.netlify.app/guide/#after

Expected output (when copied with clipboard)

// Declare a tuple type
let x: [string, number]

// Initialize it
x = ['hello', 10]
// Initialize it incorrectly
x = [10, 'hello']

Current bad output (when copied with manual selection, ctrl+c):

// Declare a tuple type
let x
: [string, number]

// Initialize it
x
 = ['hello', 10]
// Initialize it incorrectly
x
 = [10, 'hello']