1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27

use std::io::Write;

#[cfg_attr(test, mockall::automock)]
pub trait Listener: Send + Sync {
    fn warning(&self, s: String);
    fn info(&self, s: String);
}

pub struct NoOpListener;
impl Listener for NoOpListener {
    fn info(&self, _s: String) {}
    fn warning(&self, _s: String) {}
}

pub struct StdErrListener {
    pub verbose: bool,
}
impl Listener for StdErrListener {
    fn warning(&self, s: String) {
        let _ = writeln!(&mut std::io::stdout().lock(), "warning: {}", s);
    }
    fn info(&self, s: String) {
        if self.verbose {
            let _ = writeln!(&mut std::io::stdout().lock(), "info: {}", s);
        }
    }
}