Closed
Description
What it does
What does this lint do?
Remove unnecessary match for error handling when function signatures are the same.
Categories (optional)
- Kind:
style,correctness?
What is the advantage of the recommended code over the original code
Not sure if there are any performance improvements. The code is more readable and shorter though. This lint also applies for any function pair that returns the same enum, like Option<T> for example.
Drawbacks
None.
Example
// For example, a function has the signature:
fn fname(...) -> Result<T, E> { ... }
// and it is called in another function with the same signature:
fn fname2(...) -> Result<T, E> {
// This is obviously unnecessary
match fname(...) {
Ok(s) => Ok(s),
Err(e) => Err(e),
}
}Could be written as:
// For example, a function has the signature:
fn fname(...) -> Result<T, E> { ... }
// and it is called in another function with the same signature:
fn fname2(...) -> Result<T, E> {
// Much better
fname(...)
}Real world example
async fn destructure_reqwest_response(res: Response) -> Result<Generic, InternalError> {
...
}
async fn get_count(...) -> Result<Generic, InternalError> {
...
// Changed this later. Even clippy::pedantic did not detect this, so I assume that a lint is missing.
match res {
Ok(r) => match destructure_reqwest_response(r).await {
Ok(r) => Ok(r),
Err(e) => Err(e),
},
Err(_) => Err(INTERNALERROR),
}
...
}