[`fastapi`] Handle ellipsis defaults in FAST002 autofix (`FAST002`) (#20810)

## Summary

Implement handling of ellipsis (`...`) defaults in the `FAST002` autofix
to correctly differentiate between required and optional parameters in
FastAPI route definitions.

Previously, the autofix did not properly handle cases where parameters
used `...` as a default value (to indicate required parameters). This
could lead to incorrect transformations when applying the autofix.

This change updates the `FAST002` autofix logic to:
- Correctly recognize `...` as a valid FastAPI required default.
- Preserve the semantics of required parameters while still applying
other autofix improvements.
- Avoid incorrectly substituting or removing ellipsis defaults.

Fixes https://github.com/astral-sh/ruff/issues/20800

## Test Plan

Added a new test fixture at:
```crates/ruff_linter/resources/test/fixtures/fastapi/FAST002_2.py```

crates/ruff_linter/resources/test/fixtures/fastapi/FAST002_2.py

@@ -0,0 +1,87 @@
+"""Test FAST002 ellipsis handling."""
+
+from fastapi import Body, Cookie, FastAPI, Header, Query
+
+app = FastAPI()
+
+
+# Cases that should be fixed - ellipsis should be removed
+
+
+@app.get("/test1")
+async def test_ellipsis_query(
+    # This should become: param: Annotated[str, Query(description="Test param")]
+    param: str = Query(..., description="Test param"),
+) -> str:
+    return param
+
+
+@app.get("/test2")
+async def test_ellipsis_header(
+    # This should become: auth: Annotated[str, Header(description="Auth header")]
+    auth: str = Header(..., description="Auth header"),
+) -> str:
+    return auth
+
+
+@app.post("/test3")
+async def test_ellipsis_body(
+    # This should become: data: Annotated[dict, Body(description="Request body")]
+    data: dict = Body(..., description="Request body"),
+) -> dict:
+    return data
+
+
+@app.get("/test4")
+async def test_ellipsis_cookie(
+    # This should become: session: Annotated[str, Cookie(description="Session ID")]
+    session: str = Cookie(..., description="Session ID"),
+) -> str:
+    return session
+
+
+@app.get("/test5")
+async def test_simple_ellipsis(
+    # This should become: id: Annotated[str, Query()]
+    id: str = Query(...),
+) -> str:
+    return id
+
+
+@app.get("/test6")
+async def test_multiple_kwargs_with_ellipsis(
+    # This should become: param: Annotated[str, Query(description="Test", min_length=1, max_length=10)]
+    param: str = Query(..., description="Test", min_length=1, max_length=10),
+) -> str:
+    return param
+
+
+# Cases with actual default values - these should preserve the default
+
+
+@app.get("/test7")
+async def test_with_default_value(
+    # This should become: param: Annotated[str, Query(description="Test")] = "default"
+    param: str = Query("default", description="Test"),
+) -> str:
+    return param
+
+
+@app.get("/test8")
+async def test_with_default_none(
+    # This should become: param: Annotated[str | None, Query(description="Test")] = None
+    param: str | None = Query(None, description="Test"),
+) -> str:
+    return param or "empty"
+
+
+@app.get("/test9")
+async def test_mixed_parameters(
+    # First param should be fixed with default preserved  
+    optional_param: str = Query("default", description="Optional"),
+    # Second param should not be fixed because of the preceding default
+    required_param: str = Query(..., description="Required"),
+    # Third param should be fixed with default preserved
+    another_optional_param: int = Query(42, description="Another optional"),
+) -> str:
+    return f"{required_param}-{optional_param}-{another_optional_param}"

crates/ruff_linter/src/rules/fastapi/mod.rs

@@ -18,6 +18,7 @@ mod tests {
     #[test_case(Rule::FastApiRedundantResponseModel, Path::new("FAST001.py"))]
     #[test_case(Rule::FastApiNonAnnotatedDependency, Path::new("FAST002_0.py"))]
     #[test_case(Rule::FastApiNonAnnotatedDependency, Path::new("FAST002_1.py"))]
+    #[test_case(Rule::FastApiNonAnnotatedDependency, Path::new("FAST002_2.py"))]
     #[test_case(Rule::FastApiUnusedPathParameter, Path::new("FAST003.py"))]
     fn rules(rule_code: Rule, path: &Path) -> Result<()> {
         let snapshot = format!("{}_{}", rule_code.name(), path.to_string_lossy());
@@ -56,6 +57,7 @@ mod tests {
     // since `typing.Annotated` was added in Python 3.9
     #[test_case(Rule::FastApiNonAnnotatedDependency, Path::new("FAST002_0.py"))]
     #[test_case(Rule::FastApiNonAnnotatedDependency, Path::new("FAST002_1.py"))]
+    #[test_case(Rule::FastApiNonAnnotatedDependency, Path::new("FAST002_2.py"))]
     fn rules_py38(rule_code: Rule, path: &Path) -> Result<()> {
         let snapshot = format!("{}_{}_py38", rule_code.name(), path.to_string_lossy());
         let diagnostics = test_path(

crates/ruff_linter/src/rules/fastapi/rules/fastapi_non_annotated_dependency.rs

@@ -275,19 +275,42 @@ fn create_diagnostic(
                     .collect::<Vec<_>>()
                     .join(", ");
 
-                seen_default = true;
+                // Check if the default argument is ellipsis (...), which in FastAPI means "required"
-                format!(
+                let is_default_argument_ellipsis = matches!(
-                    "{parameter_name}: {binding}[{annotation}, {default_}({kwarg_list})] \
+                    dependency_call.default_argument.value(),
-                            = {default_value}",
+                    ast::Expr::EllipsisLiteral(_)
+                );
+
+                if is_default_argument_ellipsis && seen_default {
+                    // For ellipsis after a parameter with default, can't remove the default
+                    return Ok(None);
+                }
+
+                if !is_default_argument_ellipsis {
+                    // For actual default values, mark that we've seen a default
+                    seen_default = true;
+                }
+
+                let base_format = format!(
+                    "{parameter_name}: {binding}[{annotation}, {default_}({kwarg_list})]",
                     parameter_name = parameter.name,
                     annotation = checker.locator().slice(parameter.annotation.range()),
                     default_ = checker
                         .locator()
                         .slice(map_callable(parameter.default).range()),
-                    default_value = checker
+                );
+
+                if is_default_argument_ellipsis {
+                    // For ellipsis, don't add a default value since the parameter
+                    // should remain required after conversion to Annotated
+                    base_format
+                } else {
+                    // For actual default values, preserve them
+                    let default_value = checker
                         .locator()
-                        .slice(dependency_call.default_argument.value().range()),
+                        .slice(dependency_call.default_argument.value().range());
-                )
+                    format!("{base_format} = {default_value}")
+                }
             }
             _ => {
                 if seen_default {

crates/ruff_linter/src/rules/fastapi/snapshots/ruff_linter__rules__fastapi__tests__fast-api-non-annotated-dependency_FAST002_2.py.snap

@@ -0,0 +1,303 @@
+---
+source: crates/ruff_linter/src/rules/fastapi/mod.rs
+---
+FAST002 [*] FastAPI dependency without `Annotated`
+  --> FAST002_2.py:14:5
+   |
+12 | async def test_ellipsis_query(
+13 |     # This should become: param: Annotated[str, Query(description="Test param")]
+14 |     param: str = Query(..., description="Test param"),
+   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+15 | ) -> str:
+16 |     return param
+   |
+help: Replace with `typing.Annotated`
+1  | """Test FAST002 ellipsis handling."""
+2  | 
+3  | from fastapi import Body, Cookie, FastAPI, Header, Query
+4  + from typing import Annotated
+5  | 
+6  | app = FastAPI()
+7  | 
+--------------------------------------------------------------------------------
+12 | @app.get("/test1")
+13 | async def test_ellipsis_query(
+14 |     # This should become: param: Annotated[str, Query(description="Test param")]
+   -     param: str = Query(..., description="Test param"),
+15 +     param: Annotated[str, Query(description="Test param")],
+16 | ) -> str:
+17 |     return param
+18 | 
+note: This is an unsafe fix and may change runtime behavior
+
+FAST002 [*] FastAPI dependency without `Annotated`
+  --> FAST002_2.py:22:5
+   |
+20 | async def test_ellipsis_header(
+21 |     # This should become: auth: Annotated[str, Header(description="Auth header")]
+22 |     auth: str = Header(..., description="Auth header"),
+   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+23 | ) -> str:
+24 |     return auth
+   |
+help: Replace with `typing.Annotated`
+1  | """Test FAST002 ellipsis handling."""
+2  | 
+3  | from fastapi import Body, Cookie, FastAPI, Header, Query
+4  + from typing import Annotated
+5  | 
+6  | app = FastAPI()
+7  | 
+--------------------------------------------------------------------------------
+20 | @app.get("/test2")
+21 | async def test_ellipsis_header(
+22 |     # This should become: auth: Annotated[str, Header(description="Auth header")]
+   -     auth: str = Header(..., description="Auth header"),
+23 +     auth: Annotated[str, Header(description="Auth header")],
+24 | ) -> str:
+25 |     return auth
+26 | 
+note: This is an unsafe fix and may change runtime behavior
+
+FAST002 [*] FastAPI dependency without `Annotated`
+  --> FAST002_2.py:30:5
+   |
+28 | async def test_ellipsis_body(
+29 |     # This should become: data: Annotated[dict, Body(description="Request body")]
+30 |     data: dict = Body(..., description="Request body"),
+   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+31 | ) -> dict:
+32 |     return data
+   |
+help: Replace with `typing.Annotated`
+1  | """Test FAST002 ellipsis handling."""
+2  | 
+3  | from fastapi import Body, Cookie, FastAPI, Header, Query
+4  + from typing import Annotated
+5  | 
+6  | app = FastAPI()
+7  | 
+--------------------------------------------------------------------------------
+28 | @app.post("/test3")
+29 | async def test_ellipsis_body(
+30 |     # This should become: data: Annotated[dict, Body(description="Request body")]
+   -     data: dict = Body(..., description="Request body"),
+31 +     data: Annotated[dict, Body(description="Request body")],
+32 | ) -> dict:
+33 |     return data
+34 | 
+note: This is an unsafe fix and may change runtime behavior
+
+FAST002 [*] FastAPI dependency without `Annotated`
+  --> FAST002_2.py:38:5
+   |
+36 | async def test_ellipsis_cookie(
+37 |     # This should become: session: Annotated[str, Cookie(description="Session ID")]
+38 |     session: str = Cookie(..., description="Session ID"),
+   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+39 | ) -> str:
+40 |     return session
+   |
+help: Replace with `typing.Annotated`
+1  | """Test FAST002 ellipsis handling."""
+2  | 
+3  | from fastapi import Body, Cookie, FastAPI, Header, Query
+4  + from typing import Annotated
+5  | 
+6  | app = FastAPI()
+7  | 
+--------------------------------------------------------------------------------
+36 | @app.get("/test4")
+37 | async def test_ellipsis_cookie(
+38 |     # This should become: session: Annotated[str, Cookie(description="Session ID")]
+   -     session: str = Cookie(..., description="Session ID"),
+39 +     session: Annotated[str, Cookie(description="Session ID")],
+40 | ) -> str:
+41 |     return session
+42 | 
+note: This is an unsafe fix and may change runtime behavior
+
+FAST002 [*] FastAPI dependency without `Annotated`
+  --> FAST002_2.py:46:5
+   |
+44 | async def test_simple_ellipsis(
+45 |     # This should become: id: Annotated[str, Query()]
+46 |     id: str = Query(...),
+   |     ^^^^^^^^^^^^^^^^^^^^
+47 | ) -> str:
+48 |     return id
+   |
+help: Replace with `typing.Annotated`
+1  | """Test FAST002 ellipsis handling."""
+2  | 
+3  | from fastapi import Body, Cookie, FastAPI, Header, Query
+4  + from typing import Annotated
+5  | 
+6  | app = FastAPI()
+7  | 
+--------------------------------------------------------------------------------
+44 | @app.get("/test5")
+45 | async def test_simple_ellipsis(
+46 |     # This should become: id: Annotated[str, Query()]
+   -     id: str = Query(...),
+47 +     id: Annotated[str, Query()],
+48 | ) -> str:
+49 |     return id
+50 | 
+note: This is an unsafe fix and may change runtime behavior
+
+FAST002 [*] FastAPI dependency without `Annotated`
+  --> FAST002_2.py:54:5
+   |
+52 | async def test_multiple_kwargs_with_ellipsis(
+53 |     # This should become: param: Annotated[str, Query(description="Test", min_length=1, max_length=10)]
+54 |     param: str = Query(..., description="Test", min_length=1, max_length=10),
+   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+55 | ) -> str:
+56 |     return param
+   |
+help: Replace with `typing.Annotated`
+1  | """Test FAST002 ellipsis handling."""
+2  | 
+3  | from fastapi import Body, Cookie, FastAPI, Header, Query
+4  + from typing import Annotated
+5  | 
+6  | app = FastAPI()
+7  | 
+--------------------------------------------------------------------------------
+52 | @app.get("/test6")
+53 | async def test_multiple_kwargs_with_ellipsis(
+54 |     # This should become: param: Annotated[str, Query(description="Test", min_length=1, max_length=10)]
+   -     param: str = Query(..., description="Test", min_length=1, max_length=10),
+55 +     param: Annotated[str, Query(description="Test", min_length=1, max_length=10)],
+56 | ) -> str:
+57 |     return param
+58 | 
+note: This is an unsafe fix and may change runtime behavior
+
+FAST002 [*] FastAPI dependency without `Annotated`
+  --> FAST002_2.py:65:5
+   |
+63 | async def test_with_default_value(
+64 |     # This should become: param: Annotated[str, Query(description="Test")] = "default"
+65 |     param: str = Query("default", description="Test"),
+   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+66 | ) -> str:
+67 |     return param
+   |
+help: Replace with `typing.Annotated`
+1  | """Test FAST002 ellipsis handling."""
+2  | 
+3  | from fastapi import Body, Cookie, FastAPI, Header, Query
+4  + from typing import Annotated
+5  | 
+6  | app = FastAPI()
+7  | 
+--------------------------------------------------------------------------------
+63 | @app.get("/test7")
+64 | async def test_with_default_value(
+65 |     # This should become: param: Annotated[str, Query(description="Test")] = "default"
+   -     param: str = Query("default", description="Test"),
+66 +     param: Annotated[str, Query(description="Test")] = "default",
+67 | ) -> str:
+68 |     return param
+69 | 
+note: This is an unsafe fix and may change runtime behavior
+
+FAST002 [*] FastAPI dependency without `Annotated`
+  --> FAST002_2.py:73:5
+   |
+71 | async def test_with_default_none(
+72 |     # This should become: param: Annotated[str | None, Query(description="Test")] = None
+73 |     param: str | None = Query(None, description="Test"),
+   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+74 | ) -> str:
+75 |     return param or "empty"
+   |
+help: Replace with `typing.Annotated`
+1  | """Test FAST002 ellipsis handling."""
+2  | 
+3  | from fastapi import Body, Cookie, FastAPI, Header, Query
+4  + from typing import Annotated
+5  | 
+6  | app = FastAPI()
+7  | 
+--------------------------------------------------------------------------------
+71 | @app.get("/test8")
+72 | async def test_with_default_none(
+73 |     # This should become: param: Annotated[str | None, Query(description="Test")] = None
+   -     param: str | None = Query(None, description="Test"),
+74 +     param: Annotated[str | None, Query(description="Test")] = None,
+75 | ) -> str:
+76 |     return param or "empty"
+77 | 
+note: This is an unsafe fix and may change runtime behavior
+
+FAST002 [*] FastAPI dependency without `Annotated`
+  --> FAST002_2.py:81:5
+   |
+79 | async def test_mixed_parameters(
+80 |     # First param should be fixed with default preserved  
+81 |     optional_param: str = Query("default", description="Optional"),
+   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+82 |     # Second param should not be fixed because of the preceding default
+83 |     required_param: str = Query(..., description="Required"),
+   |
+help: Replace with `typing.Annotated`
+1  | """Test FAST002 ellipsis handling."""
+2  | 
+3  | from fastapi import Body, Cookie, FastAPI, Header, Query
+4  + from typing import Annotated
+5  | 
+6  | app = FastAPI()
+7  | 
+--------------------------------------------------------------------------------
+79 | @app.get("/test9")
+80 | async def test_mixed_parameters(
+81 |     # First param should be fixed with default preserved  
+   -     optional_param: str = Query("default", description="Optional"),
+82 +     optional_param: Annotated[str, Query(description="Optional")] = "default",
+83 |     # Second param should not be fixed because of the preceding default
+84 |     required_param: str = Query(..., description="Required"),
+85 |     # Third param should be fixed with default preserved
+note: This is an unsafe fix and may change runtime behavior
+
+FAST002 FastAPI dependency without `Annotated`
+  --> FAST002_2.py:83:5
+   |
+81 |     optional_param: str = Query("default", description="Optional"),
+82 |     # Second param should not be fixed because of the preceding default
+83 |     required_param: str = Query(..., description="Required"),
+   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+84 |     # Third param should be fixed with default preserved
+85 |     another_optional_param: int = Query(42, description="Another optional"),
+   |
+help: Replace with `typing.Annotated`
+
+FAST002 [*] FastAPI dependency without `Annotated`
+  --> FAST002_2.py:85:5
+   |
+83 |     required_param: str = Query(..., description="Required"),
+84 |     # Third param should be fixed with default preserved
+85 |     another_optional_param: int = Query(42, description="Another optional"),
+   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+86 | ) -> str:
+87 |     return f"{required_param}-{optional_param}-{another_optional_param}"
+   |
+help: Replace with `typing.Annotated`
+1  | """Test FAST002 ellipsis handling."""
+2  | 
+3  | from fastapi import Body, Cookie, FastAPI, Header, Query
+4  + from typing import Annotated
+5  | 
+6  | app = FastAPI()
+7  | 
+--------------------------------------------------------------------------------
+83 |     # Second param should not be fixed because of the preceding default
+84 |     required_param: str = Query(..., description="Required"),
+85 |     # Third param should be fixed with default preserved
+   -     another_optional_param: int = Query(42, description="Another optional"),
+86 +     another_optional_param: Annotated[int, Query(description="Another optional")] = 42,
+87 | ) -> str:
+88 |     return f"{required_param}-{optional_param}-{another_optional_param}"
+note: This is an unsafe fix and may change runtime behavior

crates/ruff_linter/src/rules/fastapi/snapshots/ruff_linter__rules__fastapi__tests__fast-api-non-annotated-dependency_FAST002_2.py_py38.snap

@@ -0,0 +1,303 @@
+---
+source: crates/ruff_linter/src/rules/fastapi/mod.rs
+---
+FAST002 [*] FastAPI dependency without `Annotated`
+  --> FAST002_2.py:14:5
+   |
+12 | async def test_ellipsis_query(
+13 |     # This should become: param: Annotated[str, Query(description="Test param")]
+14 |     param: str = Query(..., description="Test param"),
+   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+15 | ) -> str:
+16 |     return param
+   |
+help: Replace with `typing_extensions.Annotated`
+1  | """Test FAST002 ellipsis handling."""
+2  | 
+3  | from fastapi import Body, Cookie, FastAPI, Header, Query
+4  + from typing_extensions import Annotated
+5  | 
+6  | app = FastAPI()
+7  | 
+--------------------------------------------------------------------------------
+12 | @app.get("/test1")
+13 | async def test_ellipsis_query(
+14 |     # This should become: param: Annotated[str, Query(description="Test param")]
+   -     param: str = Query(..., description="Test param"),
+15 +     param: Annotated[str, Query(description="Test param")],
+16 | ) -> str:
+17 |     return param
+18 | 
+note: This is an unsafe fix and may change runtime behavior
+
+FAST002 [*] FastAPI dependency without `Annotated`
+  --> FAST002_2.py:22:5
+   |
+20 | async def test_ellipsis_header(
+21 |     # This should become: auth: Annotated[str, Header(description="Auth header")]
+22 |     auth: str = Header(..., description="Auth header"),
+   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+23 | ) -> str:
+24 |     return auth
+   |
+help: Replace with `typing_extensions.Annotated`
+1  | """Test FAST002 ellipsis handling."""
+2  | 
+3  | from fastapi import Body, Cookie, FastAPI, Header, Query
+4  + from typing_extensions import Annotated
+5  | 
+6  | app = FastAPI()
+7  | 
+--------------------------------------------------------------------------------
+20 | @app.get("/test2")
+21 | async def test_ellipsis_header(
+22 |     # This should become: auth: Annotated[str, Header(description="Auth header")]
+   -     auth: str = Header(..., description="Auth header"),
+23 +     auth: Annotated[str, Header(description="Auth header")],
+24 | ) -> str:
+25 |     return auth
+26 | 
+note: This is an unsafe fix and may change runtime behavior
+
+FAST002 [*] FastAPI dependency without `Annotated`
+  --> FAST002_2.py:30:5
+   |
+28 | async def test_ellipsis_body(
+29 |     # This should become: data: Annotated[dict, Body(description="Request body")]
+30 |     data: dict = Body(..., description="Request body"),
+   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+31 | ) -> dict:
+32 |     return data
+   |
+help: Replace with `typing_extensions.Annotated`
+1  | """Test FAST002 ellipsis handling."""
+2  | 
+3  | from fastapi import Body, Cookie, FastAPI, Header, Query
+4  + from typing_extensions import Annotated
+5  | 
+6  | app = FastAPI()
+7  | 
+--------------------------------------------------------------------------------
+28 | @app.post("/test3")
+29 | async def test_ellipsis_body(
+30 |     # This should become: data: Annotated[dict, Body(description="Request body")]
+   -     data: dict = Body(..., description="Request body"),
+31 +     data: Annotated[dict, Body(description="Request body")],
+32 | ) -> dict:
+33 |     return data
+34 | 
+note: This is an unsafe fix and may change runtime behavior
+
+FAST002 [*] FastAPI dependency without `Annotated`
+  --> FAST002_2.py:38:5
+   |
+36 | async def test_ellipsis_cookie(
+37 |     # This should become: session: Annotated[str, Cookie(description="Session ID")]
+38 |     session: str = Cookie(..., description="Session ID"),
+   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+39 | ) -> str:
+40 |     return session
+   |
+help: Replace with `typing_extensions.Annotated`
+1  | """Test FAST002 ellipsis handling."""
+2  | 
+3  | from fastapi import Body, Cookie, FastAPI, Header, Query
+4  + from typing_extensions import Annotated
+5  | 
+6  | app = FastAPI()
+7  | 
+--------------------------------------------------------------------------------
+36 | @app.get("/test4")
+37 | async def test_ellipsis_cookie(
+38 |     # This should become: session: Annotated[str, Cookie(description="Session ID")]
+   -     session: str = Cookie(..., description="Session ID"),
+39 +     session: Annotated[str, Cookie(description="Session ID")],
+40 | ) -> str:
+41 |     return session
+42 | 
+note: This is an unsafe fix and may change runtime behavior
+
+FAST002 [*] FastAPI dependency without `Annotated`
+  --> FAST002_2.py:46:5
+   |
+44 | async def test_simple_ellipsis(
+45 |     # This should become: id: Annotated[str, Query()]
+46 |     id: str = Query(...),
+   |     ^^^^^^^^^^^^^^^^^^^^
+47 | ) -> str:
+48 |     return id
+   |
+help: Replace with `typing_extensions.Annotated`
+1  | """Test FAST002 ellipsis handling."""
+2  | 
+3  | from fastapi import Body, Cookie, FastAPI, Header, Query
+4  + from typing_extensions import Annotated
+5  | 
+6  | app = FastAPI()
+7  | 
+--------------------------------------------------------------------------------
+44 | @app.get("/test5")
+45 | async def test_simple_ellipsis(
+46 |     # This should become: id: Annotated[str, Query()]
+   -     id: str = Query(...),
+47 +     id: Annotated[str, Query()],
+48 | ) -> str:
+49 |     return id
+50 | 
+note: This is an unsafe fix and may change runtime behavior
+
+FAST002 [*] FastAPI dependency without `Annotated`
+  --> FAST002_2.py:54:5
+   |
+52 | async def test_multiple_kwargs_with_ellipsis(
+53 |     # This should become: param: Annotated[str, Query(description="Test", min_length=1, max_length=10)]
+54 |     param: str = Query(..., description="Test", min_length=1, max_length=10),
+   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+55 | ) -> str:
+56 |     return param
+   |
+help: Replace with `typing_extensions.Annotated`
+1  | """Test FAST002 ellipsis handling."""
+2  | 
+3  | from fastapi import Body, Cookie, FastAPI, Header, Query
+4  + from typing_extensions import Annotated
+5  | 
+6  | app = FastAPI()
+7  | 
+--------------------------------------------------------------------------------
+52 | @app.get("/test6")
+53 | async def test_multiple_kwargs_with_ellipsis(
+54 |     # This should become: param: Annotated[str, Query(description="Test", min_length=1, max_length=10)]
+   -     param: str = Query(..., description="Test", min_length=1, max_length=10),
+55 +     param: Annotated[str, Query(description="Test", min_length=1, max_length=10)],
+56 | ) -> str:
+57 |     return param
+58 | 
+note: This is an unsafe fix and may change runtime behavior
+
+FAST002 [*] FastAPI dependency without `Annotated`
+  --> FAST002_2.py:65:5
+   |
+63 | async def test_with_default_value(
+64 |     # This should become: param: Annotated[str, Query(description="Test")] = "default"
+65 |     param: str = Query("default", description="Test"),
+   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+66 | ) -> str:
+67 |     return param
+   |
+help: Replace with `typing_extensions.Annotated`
+1  | """Test FAST002 ellipsis handling."""
+2  | 
+3  | from fastapi import Body, Cookie, FastAPI, Header, Query
+4  + from typing_extensions import Annotated
+5  | 
+6  | app = FastAPI()
+7  | 
+--------------------------------------------------------------------------------
+63 | @app.get("/test7")
+64 | async def test_with_default_value(
+65 |     # This should become: param: Annotated[str, Query(description="Test")] = "default"
+   -     param: str = Query("default", description="Test"),
+66 +     param: Annotated[str, Query(description="Test")] = "default",
+67 | ) -> str:
+68 |     return param
+69 | 
+note: This is an unsafe fix and may change runtime behavior
+
+FAST002 [*] FastAPI dependency without `Annotated`
+  --> FAST002_2.py:73:5
+   |
+71 | async def test_with_default_none(
+72 |     # This should become: param: Annotated[str | None, Query(description="Test")] = None
+73 |     param: str | None = Query(None, description="Test"),
+   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+74 | ) -> str:
+75 |     return param or "empty"
+   |
+help: Replace with `typing_extensions.Annotated`
+1  | """Test FAST002 ellipsis handling."""
+2  | 
+3  | from fastapi import Body, Cookie, FastAPI, Header, Query
+4  + from typing_extensions import Annotated
+5  | 
+6  | app = FastAPI()
+7  | 
+--------------------------------------------------------------------------------
+71 | @app.get("/test8")
+72 | async def test_with_default_none(
+73 |     # This should become: param: Annotated[str | None, Query(description="Test")] = None
+   -     param: str | None = Query(None, description="Test"),
+74 +     param: Annotated[str | None, Query(description="Test")] = None,
+75 | ) -> str:
+76 |     return param or "empty"
+77 | 
+note: This is an unsafe fix and may change runtime behavior
+
+FAST002 [*] FastAPI dependency without `Annotated`
+  --> FAST002_2.py:81:5
+   |
+79 | async def test_mixed_parameters(
+80 |     # First param should be fixed with default preserved  
+81 |     optional_param: str = Query("default", description="Optional"),
+   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+82 |     # Second param should not be fixed because of the preceding default
+83 |     required_param: str = Query(..., description="Required"),
+   |
+help: Replace with `typing_extensions.Annotated`
+1  | """Test FAST002 ellipsis handling."""
+2  | 
+3  | from fastapi import Body, Cookie, FastAPI, Header, Query
+4  + from typing_extensions import Annotated
+5  | 
+6  | app = FastAPI()
+7  | 
+--------------------------------------------------------------------------------
+79 | @app.get("/test9")
+80 | async def test_mixed_parameters(
+81 |     # First param should be fixed with default preserved  
+   -     optional_param: str = Query("default", description="Optional"),
+82 +     optional_param: Annotated[str, Query(description="Optional")] = "default",
+83 |     # Second param should not be fixed because of the preceding default
+84 |     required_param: str = Query(..., description="Required"),
+85 |     # Third param should be fixed with default preserved
+note: This is an unsafe fix and may change runtime behavior
+
+FAST002 FastAPI dependency without `Annotated`
+  --> FAST002_2.py:83:5
+   |
+81 |     optional_param: str = Query("default", description="Optional"),
+82 |     # Second param should not be fixed because of the preceding default
+83 |     required_param: str = Query(..., description="Required"),
+   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+84 |     # Third param should be fixed with default preserved
+85 |     another_optional_param: int = Query(42, description="Another optional"),
+   |
+help: Replace with `typing_extensions.Annotated`
+
+FAST002 [*] FastAPI dependency without `Annotated`
+  --> FAST002_2.py:85:5
+   |
+83 |     required_param: str = Query(..., description="Required"),
+84 |     # Third param should be fixed with default preserved
+85 |     another_optional_param: int = Query(42, description="Another optional"),
+   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+86 | ) -> str:
+87 |     return f"{required_param}-{optional_param}-{another_optional_param}"
+   |
+help: Replace with `typing_extensions.Annotated`
+1  | """Test FAST002 ellipsis handling."""
+2  | 
+3  | from fastapi import Body, Cookie, FastAPI, Header, Query
+4  + from typing_extensions import Annotated
+5  | 
+6  | app = FastAPI()
+7  | 
+--------------------------------------------------------------------------------
+83 |     # Second param should not be fixed because of the preceding default
+84 |     required_param: str = Query(..., description="Required"),
+85 |     # Third param should be fixed with default preserved
+   -     another_optional_param: int = Query(42, description="Another optional"),
+86 +     another_optional_param: Annotated[int, Query(description="Another optional")] = 42,
+87 | ) -> str:
+88 |     return f"{required_param}-{optional_param}-{another_optional_param}"
+note: This is an unsafe fix and may change runtime behavior