AST safety check fails to catch incorrect f-string change #4268
Description
Describe the style change
I wonder if f-strings should be formatted at all.
Examples in the current Black style
print(f"{"|".join(['a','b','c'])}")Desired style
print(f"{"|".join(['a','b','c'])}")Note
There's no change to the input here.
Additional context
Black formats the "|" to become " | " and that affects the output which cannot be desired.
Black formats the snippet like this currently:
print(f"{" | ".join(['a','b','c'])}")