rust/tests/ui/if_then_some_else_none.fixed

120 lines
2.9 KiB
Rust

#![warn(clippy::if_then_some_else_none)]
#![allow(clippy::redundant_pattern_matching, clippy::unnecessary_lazy_evaluations)]
fn main() {
// Should issue an error.
let _ = foo().then(|| { println!("true!"); "foo" });
// Should issue an error when macros are used.
let _ = matches!(true, true).then(|| { println!("true!"); matches!(true, false) });
// Should issue an error. Binary expression `o < 32` should be parenthesized.
let x = Some(5);
let _ = x.and_then(|o| (o < 32).then_some(o));
//~^ ERROR: this could be simplified with `bool::then_some`
// Should issue an error. Unary expression `!x` should be parenthesized.
let x = true;
let _ = (!x).then_some(0);
//~^ ERROR: this could be simplified with `bool::then_some`
// Should not issue an error since the `else` block has a statement besides `None`.
let _ = if foo() {
println!("true!");
Some("foo")
} else {
eprintln!("false...");
None
};
// Should not issue an error since there are more than 2 blocks in the if-else chain.
let _ = if foo() {
println!("foo true!");
Some("foo")
} else if bar() {
println!("bar true!");
Some("bar")
} else {
None
};
let _ = if foo() {
println!("foo true!");
Some("foo")
} else {
bar().then(|| {
println!("bar true!");
"bar"
})
};
// Should not issue an error since the `then` block has `None`, not `Some`.
let _ = if foo() { None } else { Some("foo is false") };
// Should not issue an error since the `else` block doesn't use `None` directly.
let _ = if foo() { Some("foo is true") } else { into_none() };
// Should not issue an error since the `then` block doesn't use `Some` directly.
let _ = if foo() { into_some("foo") } else { None };
}
#[clippy::msrv = "1.49"]
fn _msrv_1_49() {
// `bool::then` was stabilized in 1.50. Do not lint this
let _ = if foo() {
println!("true!");
Some(149)
} else {
None
};
}
#[clippy::msrv = "1.50"]
fn _msrv_1_50() {
let _ = foo().then(|| { println!("true!"); 150 });
}
fn foo() -> bool {
unimplemented!()
}
fn bar() -> bool {
unimplemented!()
}
fn into_some<T>(v: T) -> Option<T> {
Some(v)
}
fn into_none<T>() -> Option<T> {
None
}
// Should not warn
fn f(b: bool, v: Option<()>) -> Option<()> {
if b {
v?; // This is a potential early return, is not equivalent with `bool::then`
Some(())
} else {
None
}
}
fn issue11394(b: bool, v: Result<(), ()>) -> Result<(), ()> {
let x = if b {
#[allow(clippy::let_unit_value)]
let _ = v?;
Some(())
} else {
None
};
Ok(())
}
const fn issue12103(x: u32) -> Option<u32> {
// Should not issue an error in `const` context
if x > 42 { Some(150) } else { None }
}