ruff/crates/ruff_python_parser/tests
Brent Westbrook 38c074e67d
Catch syntax errors in nested interpolations before Python 3.12 (#20949)
Summary
--

This PR fixes the issue I added in #20867 and noticed in #20930. Cases
like this
cause an error on any Python version:

```py
f"{1:""}"
```

which gave me a false sense of security before. Cases like this are
still
invalid only before 3.12 and weren't flagged after the changes in
#20867:

```py
f'{1: abcd "{'aa'}" }'
           # ^  reused quote
f'{1: abcd "{"\n"}" }'
            # ^  backslash
```

I didn't recognize these as nested interpolations that also need to be
checked
for invalid expressions, so filtering out the whole format spec wasn't
quite
right. And `elements.interpolations()` only iterates over the outermost 
interpolations, not the nested ones.

There's basically no code change in this PR, I just moved the existing
check
from `parse_interpolated_string`, which parses the entire string, to
`parse_interpolated_element`. This kind of seems more natural anyway and
avoids
having to try to recursively visit nested elements after the fact in
`parse_interpolated_string`. So viewing the diff with something like

```
git diff --color-moved --ignore-space-change --color-moved-ws=allow-indentation-change main
```

should make this more clear.

Test Plan
--

New tests
2025-10-20 09:03:13 -04:00
..
snapshots Catch syntax errors in nested interpolations before Python 3.12 (#20949) 2025-10-20 09:03:13 -04:00
fixtures.rs [syntax-errors]: break outside loop F701 (#20556) 2025-10-13 20:00:59 +00:00
generate_inline_tests.rs Update Rust crate anyhow to v1.0.100 (#20499) 2025-09-22 09:51:52 +02:00