flow::runner::running(): what a runner is running now, for its host to show (refs andymccall/oxygenhub-android#8) 1a50d4dae89c

- **What a runner is running, for its host (oxygenhub-android#8):** `flow::runner::running()` lists the jobs this runner is running now (`owner/name #run job`), each from just before it starts until it ends, so the Android app can show them on its card and notification.

                        let _shown = Running::start(id, format!("{} #{} {}", claim.repo, claim.run_number, claim.job.name));

/// The jobs this runner is running now, for a host to show (the Android

/// app's card and notification, oxygenhub-android#8): by job id,

/// "owner/name #run job".

static RUNNING_NOW: std::sync::Mutex<std::collections::BTreeMap<i64, String>> = std::sync::Mutex::new(std::collections::BTreeMap::new());

/// A job shown in [`running`] while this lives.

struct Running(i64);

impl Running {

    fn start(id: i64, what: String) -> Running {

        RUNNING_NOW.lock().unwrap_or_else(|p| p.into_inner()).insert(id, what);

        Running(id)

    }

}

impl Drop for Running {

    fn drop(&mut self) {

        RUNNING_NOW.lock().unwrap_or_else(|p| p.into_inner()).remove(&self.0);

    }

}

/// What this runner is running now: "owner/name #run job" for each job, in

/// the order claimed.

pub fn running() -> Vec<String> {

    RUNNING_NOW.lock().unwrap_or_else(|p| p.into_inner()).values().cloned().collect()

}

    #[test]

    fn running_jobs_show_while_they_run() {

        let a = super::Running::start(-41, "andy/demo #7 test".into());

        let b = super::Running::start(-40, "andy/demo #7 lint".into());

        let now = super::running();

        assert!(now.contains(&"andy/demo #7 test".to_string()) && now.contains(&"andy/demo #7 lint".to_string()));

        drop(a);

        assert!(!super::running().contains(&"andy/demo #7 test".to_string()));

        drop(b);

        assert!(!super::running().iter().any(|r| r.starts_with("andy/demo #7")));

    }