The nightly gc keeps Flow's artifacts 4597750166e7

- **Flow's artifacts survive the nightly gc (#126).** They are named only in the hub's database, so garbage collection found them unreachable and would have deleted each one 14 days after its run: coverage files, test reports and dist files alike. The nightly gc now keeps every artifact a repository's runs name.

/// Every artifact blob a repository's runs keep, for garbage collection to

/// keep too (#126): the database is the only thing that names them.

pub async fn artifact_blobs(pool: &Pool, repo_id: i64) -> sqlx::Result<Vec<String>> {

    sqlx::query_scalar(

        "SELECT DISTINCT a.blob FROM flow_artifacts a JOIN flow_jobs j ON j.id = a.job_id JOIN flow_runs r ON r.id = j.run_id WHERE r.repo_id = ?",

    )

    .bind(repo_id)

    .fetch_all(pool)

    .await

}

        // Flow's artifacts are named only in the database: kept as roots,

        // or gc would prune them after the grace period (#126). A listing

        // that fails skips this repository rather than risk them.

        let keep: Vec<oxy_core::hash::ObjectRef> = match db::flow::artifact_blobs(&app.db, row.id).await {

            Ok(blobs) => blobs.iter().filter_map(|b| oxy_core::hash::ObjectRef::from_hex(b)).collect(),

            Err(e) => {

                tracing::warn!("gc: {slug}: listing its artifacts: {e}; skipped");

                continue;

            }

        };

        let result = app

            .repos

            .write(&name, move |repo, _| Ok(repo.gc_keeping(false, &keep, &mut |phase| tracing::debug!("gc {label}: {phase}"))?))

            .await;

    // The nightly gc keeps it (#126): only the database names it, so with

    // no grace period a gc that did not root it would prune it at once.

    {

        let name = RepoName::parse("andy/demo").unwrap();

        let mut hosted = oxy_core::repo::Repo::open(&h.app.repos.dir(&name)).unwrap();

        hosted.config.set("core.gc-grace", "0").unwrap();

        hosted.save_config().unwrap();

    }

    let done = oxygenhub::maintenance::gc_all(&h.app).await;

    assert!(done.iter().all(|d| !d.failed), "{done:?}");

    let (st, got) = get_bytes(&h.app, &link).await;

    assert_eq!((st, got == body), (StatusCode::OK, true), "the artifact survives gc");