craft-update: a check that answers during an installation reports the installation

A requested check still running when the user starts the installation from
the prompt answered with its own result once it finished, which replaced
Installing or Ready with UpToDate, the check error or nothing. Its answer is
now logged, and a requested check reports Installing, Ready or the recorded
helper failure, as a check started during the installation does.

crates/update/src/updater.rs

@@ -408,6 +408,19 @@ impl Updater {
     /// the outcome of the last update ([`Self::read_outcome`]).
     fn finish_check(&mut self, answer: Checked) {
         let requested = std::mem::take(&mut self.requested);
+        // A check that was running when an installation started answers with the installation's
+        // state: the update installing, ready, or the recorded helper failure.
+        if self.install.is_some() || self.installed {
+            match &answer {
+                Ok(Some(release)) => log::info!("{} update check found {} while an update installs", self.app.name, release.tag),
+                Ok(None) => log::info!("{} update check found nothing newer while an update installs", self.app.name),
+                Err(e) => log::warn!("{} update check failed while an update installs: {e}", self.app.name),
+            }
+            if requested {
+                self.status = self.pending_status();
+            }
+            return;
+        }
         // The launcher may have pinned or unpinned the app while the check ran: whatever the
         // answer, an app it manages offers nothing and says so.
         if self.read_choice() {
@@ -1409,6 +1422,43 @@ mod tests {
         }
     }
 
+    /// A requested check that answers after an installation started reports the installation,
+    /// not its own answer, whether the update is still installing or already waits for the close.
+    #[test]
+    fn a_check_answering_during_an_update_reports_the_update() {
+        let ctx = egui::Context::default();
+        for answer in [Ok(None), Err("offline".to_owned()), Ok(Some(newer()))] {
+            let mut u = updater(Ok(None));
+            u.offer(newer());
+            u.check_now(&ctx);
+            assert_eq!(u.status(), &Status::Checking);
+            let (check_tx, check_rx) = channel();
+            u.check = Some(check_rx);
+            let (tx, rx) = channel();
+            u.install = Some((rx, newer()));
+            assert!(check_tx.send(answer.clone()).is_ok());
+            u.tick(&ctx);
+            assert_eq!(u.status(), &Status::Installing, "a check answering {answer:?} while installing");
+            assert!(tx.send(Ok(Restart::scheduled())).is_ok());
+            u.tick(&ctx);
+            assert_eq!(u.status(), &Status::Ready, "after {answer:?}");
+
+            let mut u = updater(Ok(None));
+            u.offer(newer());
+            u.check_now(&ctx);
+            let (check_tx, check_rx) = channel();
+            u.check = Some(check_rx);
+            let (tx, rx) = channel();
+            u.install = Some((rx, newer()));
+            assert!(tx.send(Ok(Restart::scheduled())).is_ok());
+            u.tick(&ctx);
+            assert!(u.check.is_some(), "the check is still running");
+            assert!(check_tx.send(answer.clone()).is_ok());
+            u.tick(&ctx);
+            assert_eq!(u.status(), &Status::Ready, "a check answering {answer:?} after the install finished");
+        }
+    }
+
     /// A failed installation closes a result window showing it; the prompt says why.
     #[test]
     fn a_failed_install_ends_the_installing_status() {