## Summary
The initial purpose was to fix#15043, where code like this:
```python
from fastapi import FastAPI, Query
app = FastAPI()
@app.get("/test")
def handler(echo: str = Query("")):
return echo
```
was being fixed to the invalid code below:
```python
from typing import Annotated
from fastapi import FastAPI, Query
app = FastAPI()
@app.get("/test")
def handler(echo: Annotated[str, Query("")]): # changed
return echo
```
As @MichaReiser pointed out, the correct fix is:
```python
from typing import Annotated
from fastapi import FastAPI, Query
app = FastAPI()
@app.get("/test")
def handler(echo: Annotated[str, Query()] = ""): # changed
return echo
```
After fixing the issue for `Query`, I realized that other classes like
`Path`, `Body`, `Cookie`, `Header`, `File`, and `Form` also looked
susceptible to this issue. The last few commits should handle these too,
which I think means this will also close#12913.
I had to reorder the arguments to the `do_stuff` test case because the
new fix removes some default argument values (eg for `Path`:
`some_path_param: str = Path()` becomes `some_path_param: Annotated[str,
Path()]`).
There's also #14484 related to this rule. I'm happy to take a stab at
that here or in a follow up PR too.
## Test Plan
`cargo test`
I also checked the fixed output with `uv run --with fastapi
FAST002_0.py`, but it required making a bunch of additional changes to
the test file that I wasn't sure we wanted in this PR.
---------
Co-authored-by: Micha Reiser <micha@reiser.io>
This adds the `fast-api-unused-path-parameter` lint rule, as described
in #12632.
I'm still pretty new to rust, so the code can probably be improved, feel
free to tell me if there's any changes i should make.
Also, i needed to add the `add_parameter` edit function, not sure if it
was in the scope of the PR or if i should've made another one.
