tests/source/cfg_select_edge_cases.rs

//@ rustfmt-unstable: true
//@ rustfmt-edition: 2024

// We need to make sure we're not adding or removing important braces

// <https://github.com/rust-lang/rustfmt/issues/7045#issuecomment-6182909709>
struct LoudDrop(&'static str);
impl Drop for LoudDrop {
    fn drop(&mut self) {
        println!("drop {}", self.0);
    }
}

fn main() {
    cfg_select! {
        _ => {{ (LoudDrop("temp"), LoudDrop("value")).1 }}
    };
    println!("end");
}

// <https://github.com/rust-lang/rustfmt/issues/7045#issuecomment-6183194180>
fn works() -> i32 {
    { 1 }
    cfg_select! {
        _ => {}
    }
}

fn fails() -> i32 {
    { 1 }
    cfg_select! {
        _ => {{}}
    }
}

// <https://github.com/rust-lang/rustfmt/issues/7045#issuecomment-6183219250>
fn works() {
    let x = cfg_select! {
        _ => { #[cfg(true)] 1 }
    };
}

fn fails() {
    let x = cfg_select! {
        // rustfmt will add braces here
        _ => #[cfg(true)] 1
    };
}

// Note, the weird brace placement above seems to be an existing issue with match arms.
fn check_match_block_formatting() {
    match x {
        _ => { #[cfg(true)] 1 }
    }
}

fn cfg_select_comments_that_might_get_lost() {
    cfg_select! {
        _ => { // after opening brace
            { x }
        // before closing brace
        }
    }
    cfg_select! {
        _ => /* after => */ {{ x }}
    }
    cfg_select! {
        _ /* before arrow */ => {{ x }}
    }

    cfg_select! {
        three_blocks_exclamation_point => {{/* a */{ b; c } /* d */}},
        // No trailing comma in source
        three_blocks_exclamation_point => {{/* a */{ b; c } /* d */}}
    }
}

fn other_cfg_select_cases() {
    cfg_select! {
        three_blocks_exclamation_point => {{{ a; b }}},
        // No trailing comma in source
        three_blocks_exclamation_point => {{{ a; b }}}
    }

    cfg_select! {
        outer_unsafe_block => unsafe { { .. } },
        // No trailing comma in source
        outer_unsafe_block => unsafe { { .. } }
    }
    cfg_select! {
        outer_const_block => const { { .. } },
        // No trailing comma in source
        outer_const_block => const { { .. } }
    }
    cfg_select! {
        outer_async_block => async { { .. } },
        // No trailing comma in source
        outer_async_block => async { { .. } }
    }
    cfg_select! {
        outer_gen_block => gen { { .. } },
        // No trailing comma in source
        outer_gen_block => gen { { .. } }
    }
    cfg_select! {
        outer_try_block => try { { .. } },
        // No trailing comma in source
        outer_try_block => try { { .. } }
    }
    cfg_select! {
        outer_block_with_label => 'a: { { .. } },
        // No trailing comma in source
        outer_block_with_label => 'a: { { .. } }
    }

    // outer attr syntax currently isn't valid syntax.
    // Maybe that will change in the future so keeping this test case around.
    cfg_select! {
        outer_block_with_outer_attr => #[foo] { { .. } },
        // No trailing comma in source
        outer_block_with_outer_attr => #[foo] { { .. } }
    }
    cfg_select! {
        outer_block_with_inner_attr => { #![foo] { .. } },
        // No trailing comma in source
        outer_block_with_inner_attr => { #![foo] { .. } }
    }

    cfg_select! {
        inner_unsafe_block => { unsafe { .. } },
        // No trailing comma in source
        inner_unsafe_block => { unsafe { .. } }
    }
    cfg_select! {
        inner_const_block => { const { .. } },
        // No trailing comma in source
        inner_const_block => { const { .. } }
    }
    cfg_select! {
        inner_async_block => { async { .. } },
        // No trailing comma in source
        inner_async_block => { async { .. } }
    }
    cfg_select! {
        inner_gen_block => { gen { .. } },
        // No trailing comma in source
        inner_gen_block => { gen { .. } }
    }
    cfg_select! {
        inner_try_block => { try { .. } },
        // No trailing comma in source
        inner_try_block => { try { .. } }
    }
    cfg_select! {
        inner_block_with_label => { 'a: { .. } },
        // No trailing comma in source
        inner_block_with_label => { 'a: { .. } }
    }
    cfg_select! {
        inner_block_with_outer_attr => { #[foo] { .. } },
        // No trailing comma in source
        inner_block_with_outer_attr => { #[foo] { .. } }
    }
    cfg_select! {
        inner_block_with_inner_attr => { { #![foo] } },
        // No trailing comma in source
        inner_block_with_inner_attr => { { #![foo] } }
    }

    cfg_select! { _ => v, }.push(2);      // place expr

    // No trailing comma in source
    cfg_select! { _ => v }.push(2);      // place expr

    cfg_select! { _ => {{ v }}, }.push(3); // value expr

    // No trailing comma in source
    cfg_select! { _ => {{ v }} }.push(3); // value expr

    // Doc comments
    cfg_select! {
        // rustfmt adds braces
        _ =>
        (///
        {})
    }

    cfg_select! {
        _ => {{
            //!
            {}
        }}
    }

    cfg_select! {
                _ => {
    #[inline]
    || {     }}
            };
}

fn long_predicate() {
    let a = cfg_select! {
        all(target_os = "linux", target_arch = "x86_64", target_env = "gnu", feature = "hello", feature = "world") => {{ x }},
    };
}

fn with_trailing_comma_fits_max_width() {
    cfg_select! {
        // max_width = 100 ------------------------------------------------------------------------|
        all(target_os = "linux", target_arch = "x86_64", target_env = "gnu") => {{ xxxxxxxxxxxxx }},
        all(
            target_os = "linux",
            target_arch = "x86_64",
            target_env = "gnu",
            feature = "hello",
            feature = "world"
        ) => {{ xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx }},
        _ => {{ xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx }},
    }
}

fn with_trailing_comma_exceeds_max_width() {
    cfg_select! {
        // max_width = 100 ------------------------------------------------------------------------|
        all(target_os = "linux", target_arch = "x86_64", target_env = "gnu") => {{ xxxxxxxxxxxxxx }},
        all(
            target_os = "linux",
            target_arch = "x86_64",
            target_env = "gnu",
            feature = "hello",
            feature = "world"
        ) => {{ xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx }},
        _ => {{ xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx }},
    }
}

fn without_trailing_comma_fits_max_width() {
    cfg_select! {
        // max_width = 100 ------------------------------------------------------------------------|
        all(target_os = "linux", target_arch = "x86_64", target_env = "gnu") => {{ xxxxxxxxxxxxxx }}
        all(
            target_os = "linux",
            target_arch = "x86_64",
            target_env = "gnu",
            feature = "hello",
            feature = "world"
        ) => {{ xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx }}
        _ => {{ xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx }}
    }
}

fn without_trailing_comma_exceeds_max_width() {
    cfg_select! {
        // max_width = 100 ------------------------------------------------------------------------|
        all(target_os = "linux", target_arch = "x86_64", target_env = "gnu") => {{ xxxxxxxxxxxxxxx }}
        all(
            target_os = "linux",
            target_arch = "x86_64",
            target_env = "gnu",
            feature = "hello",
            feature = "world"
        ) => {{ xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx }}
        _ => {{ xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx }}
    }
}