rust/tests/ui/ok_expect.rs

#![allow(clippy::unnecessary_literal_unwrap)]

use std::io;

struct MyError(()); // doesn't implement Debug

#[derive(Debug)]
struct MyErrorWithParam<T> {
    x: T,
}

fn main() {
    let res: Result<i32, ()> = Ok(0);
    let _ = res.unwrap();

    res.ok().expect("disaster!");
    //~^ ok_expect

    res.ok()
        .expect("longlonglonglonglonglonglonglonglonglonglonglonglonglong");
    //~^^ ok_expect

    let resres = res;
    resres
        .ok()
        .expect("longlonglonglonglonglonglonglonglonglonglonglonglonglong");
    //~^^^ ok_expect

    // this one has a suboptimal suggestion, but oh well
    std::process::Command::new("rustc")
        .arg("-vV")
        .output()
        .ok()
        .expect("failed to get rustc version");
    //~^^^^^ ok_expect

    // the following should not warn, since `expect` isn't implemented unless
    // the error type implements `Debug`
    let res2: Result<i32, MyError> = Ok(0);
    res2.ok().expect("oh noes!");
    let res3: Result<u32, MyErrorWithParam<u8>> = Ok(0);
    res3.ok().expect("whoof");
    //~^ ok_expect

    let res4: Result<u32, io::Error> = Ok(0);
    res4.ok().expect("argh");
    //~^ ok_expect

    let res5: io::Result<u32> = Ok(0);
    res5.ok().expect("oops");
    //~^ ok_expect

    let res6: Result<u32, &str> = Ok(0);
    res6.ok().expect("meh");
    //~^ ok_expect
}