Formatter can't recognize newline missing

[ShiKaiWi]

Description
Now the rust formatter can't recognize the necessary newline missing, e.g.:

use crate::{
    instance::{Instance, InstanceRef},
    mysql::{error::*, worker::MysqlWorker},
};
pub struct MysqlService<C, Q> {

Make the formatter can fix this case.

Proposal
No proposal yet.

Additional context

[jiacai2050]

There is a tracking issue in rustfmt:

• [unstable option] blank_lines_lower_bound rust-lang/rustfmt#3382

[waynexia]

current version of blank_lines_lower_bound is not what we want: https://rust-lang.github.io/rustfmt/?version=v1.5.0&search=#blank_lines_lower_bound

its example behavior is a bit wired

fn foo() {

    println!("a");
}

fn bar() {

    println!("b");

    println!("c");
}

[jiacai2050]

current version of blank_lines_lower_bound is not what we want

This comment says it's already been fixed in this rust-lang/rustfmt#4295, just not released...

[ygf11]

I think rust-lang/rustfmt#4295 is merged to the rustfmt-v2-rc branch, which is not going to release.

So the current release(rustfmt-v1) does not contain this patch.

rustfmt-v2 tracking issue:
rust-lang/rustfmt#3887

[jiacai2050]

Closing since this won't be fixed with rustfmt-v1