Enable tester feature in websocket example

devtools/src/lib.rs

@@ -104,10 +104,7 @@ where
         state.title(&self.program, window)
     }
 
-    fn subscription(
-        &self,
-        state: &Self::State,
-    ) -> runtime::futures::Subscription<Self::Message> {
+    fn subscription(&self, state: &Self::State) -> Subscription<Self::Message> {
         state.subscription(&self.program)
     }
 
@@ -438,9 +435,19 @@ where
     }
 
     fn subscription(&self, program: &P) -> Subscription<Event<P>> {
-        let subscription =
-            program.subscription(&self.state).map(Event::Program);
-        debug::subscriptions_tracked(subscription.units());
+        let subscription = match &self.mode {
+            Mode::Open { tester } if !tester.is_idle() => {
+                tester.subscription(program).map(Event::Tester)
+            }
+            _ => {
+                let subscription =
+                    program.subscription(&self.state).map(Event::Program);
+
+                debug::subscriptions_tracked(subscription.units());
+
+                subscription
+            }
+        };
 
         let hotkeys =
             futures::keyboard::on_key_press(|key, _modifiers| match key {
@@ -473,7 +480,11 @@ where
     }
 
     fn scale_factor(&self, program: &P, window: window::Id) -> f64 {
-        program.scale_factor(self.state(), window)
+        if let Mode::Open { .. } = &self.mode {
+            1.0
+        } else {
+            program.scale_factor(self.state(), window)
+        }
     }
 
     fn state(&self) -> &P::State {

devtools/src/tester.rs

@@ -9,6 +9,7 @@ use crate::core::alignment::Horizontal::Right;
 use crate::core::border;
 use crate::core::window;
 use crate::core::{Element, Event, Size, Theme};
+use crate::futures::Subscription;
 use crate::futures::futures::channel::mpsc;
 use crate::icon;
 use crate::program;
@@ -62,8 +63,12 @@ impl<P: Program + 'static> Tester<P> {
         }
     }
 
+    pub fn is_idle(&self) -> bool {
+        matches!(self.state, State::Idle)
+    }
+
     pub fn is_busy(&self) -> bool {
-        matches!(self.state, State::Idle | State::Playing { .. })
+        matches!(self.state, State::Recording { .. } | State::Playing { .. })
     }
 
     pub fn update(&mut self, program: &P, message: Message) -> Task<Tick<P>> {
@@ -160,6 +165,15 @@ impl<P: Program + 'static> Tester<P> {
         }
     }
 
+    pub fn subscription(&self, program: &P) -> Subscription<Tick<P>> {
+        match &self.state {
+            State::Idle | State::Playing { .. } => Subscription::none(),
+            State::Recording { state } => {
+                program.subscription(state).map(Tick::Program)
+            }
+        }
+    }
+
     pub fn view<'a, T: 'static>(
         &'a self,
         program: &P,