lint to check redundant propagation

What it does

in a caller function that returns the same type as the called function, it checks if the caller function propagates the function and returns the Ok value the called function would return

Lint Name

redundant_propagation

Category

pedantic

Advantage

• reduce code length to just a line
• avoid possible overhead because of the implicit into call by ?
• make the code more readable to read

Drawbacks

• it may be a bit restrictive so maybe for that category
• it is also realistically only useful for Results whose Ok variant is a unit, like Result<(), E>

Example

fn foo() -> Result<(), String> {
    Ok(())
}

fn bar() -> Result<(), String> {
    foo()?;
    Ok(())
}

Could be written as:

fn foo() -> Result<(), String> {
    Ok(())
}

fn bar() -> Result<(), String> {
    foo()
}

No file or test is named in the issue. Start by locating existing Clippy lint implementations and their tests, then compare the proposal with established lint patterns. Done means the lint identifies the shown redundant Result propagation case, including unit Ok results, while respecting the stated restrictions.