ASP0004: Do not use action results with route handlers
Value | |
---|---|
Rule ID | ASP0004 |
Category | Usage |
Fix is breaking or non-breaking | Non-breaking |
Cause
A route handler delegate returns a value that implements IActionResult.
Rule description
Route handler endpoints do not support executing MVC's IActionResult
instances. Returning an IActionResult
that doesn't implement IResult
results in serializing the result instance rather than executing the result.
app.MapGet("/todos/{id}", (int id) => new JsonResult(new Todo { .. }));
How to fix violations
To fix a violation of this rule, make sure that endpoint's route handler returns an IResult type by using the Results extension methods.
app.MapGet("/todos/{id}", (int id) => Results.Json(new Todo { .. }));
When to suppress warnings
Do not suppress a warning from this rule. Returning an IActionResult
that doesn't implement IResult
results in serializing the result instance rather than executing the result.