IDE's editor corrupts code when return types are inserted

[JaroslavTulach]

While investigating better behavior of type classes I created following program:

from Standard.Base import all
import Standard.Visualization

type R
    private V a:Text i:Integer

    as_text self = self
    as_both self = self
    as_int self = self

Text.from (that:R) = that.a
Integer.from (that:R) = that.i

main =
    n = R.V "Hi" 3
    t1 = n.as_text
    b2 = n.as_both
    i3 = n.as_int

and I tried to "type it" by enforcing return types of as_text, as_both and as_int methods. The desired state is:

    as_text self -> Text = self
    as_both self -> Text & Integer = self
    as_int self -> Integer = self

however this is what I get when trying to type it in the IDE's editor (and reload to see what actually got saved on disk):

Your experience may vary - but I expect the result to be similarly corrupted just like mine on 2024.5.1-nightly.2024.11.3 release. The typos seem unfixable. At the end I had to use external editor to get the correct code.

[kazcw]

This shows the inadequacy of our GUI parse/print-round trip tests. We should have a check in CI similar to the Rust parser's ./run libraries lint that ensures all .enso sources in libraries and tests are accurately represented; then the unit tests would only need to cover syntax errors and oddities that don't occur in idiomatic code.