Updates: a ready update starts its helper when the app exits (#6688)

crates/ui-egui/Cargo.toml

@@ -29,7 +29,8 @@ pdfcraft-model = { workspace = true }
 pdfcraft-platform = { workspace = true }
 egui = { workspace = true, features = ["bytemuck", "default_fonts", "monochrome_emoji_fonts"] }
 egui_extras = { workspace = true }
-eframe = { workspace = true, features = ["default_fonts", "wgpu", "accesskit", "persistence", "links", "clipboard"] }
+# `glow` is always on: `eframe::App::on_exit` takes a GL context when that feature is enabled.
+eframe = { workspace = true, features = ["default_fonts", "wgpu", "glow", "accesskit", "persistence", "links", "clipboard"] }
 serde = { workspace = true }
 serde_json = { workspace = true }
 log = { workspace = true }

crates/ui-egui/src/app.rs

@@ -468,6 +468,11 @@ impl eframe::App for PdfCraftApp {
         storage.set_string("pdfcraft", self.persist());
     }
 
+    /// Starts an update that waits for the exit. On macOS the process ends before the app is dropped.
+    fn on_exit(&mut self, _gl: Option<&eframe::glow::Context>) {
+        self.updates.exiting();
+    }
+
     /// Each frame's work before drawing: opens, operating-system and control-channel requests,
     /// the quit guard, shortcuts, and the background jobs' results.
     ///

crates/ui-egui/src/platform/updates.rs

@@ -27,6 +27,9 @@ pub(crate) struct Updates {
     startup_check: bool,
     #[cfg(not(target_arch = "wasm32"))]
     check_requested: bool,
+    /// How many times `on_exit` called [`Updates::exiting`].
+    #[cfg(test)]
+    exits: u32,
 }
 
 impl Default for Updates {
@@ -39,6 +42,20 @@ impl Default for Updates {
             startup_check: false,
             #[cfg(not(target_arch = "wasm32"))]
             check_requested: false,
+            #[cfg(test)]
+            exits: 0,
+        }
+    }
+}
+
+impl Updates {
+    /// Starts the helper of an update that waits for the app to exit. Later calls do nothing.
+    pub(crate) fn exiting(&mut self) {
+        #[cfg(not(target_arch = "wasm32"))]
+        self.updater.start_pending_update();
+        #[cfg(test)]
+        {
+            self.exits += 1;
         }
     }
 }
@@ -122,3 +139,16 @@ pub(crate) fn dialog(app: &mut PdfCraftApp, ctx: &egui::Context) {
     #[cfg(target_arch = "wasm32")]
     let _ = (app, ctx);
 }
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use eframe::App as _;
+
+    #[test]
+    fn on_exit_calls_the_update_exit_hook_once() {
+        let mut app = PdfCraftApp::new();
+        app.on_exit(None);
+        assert_eq!(app.updates.exits, 1);
+    }
+}