Merge branch 'bugfix/flaky_live_view_tests' into 'main'

Fix flaky live view tests on CI

See merge request !65

tests/test_live_view.py

@@ -35,17 +35,45 @@ def advance_frames(view: LiveViewT, n_frames: int):
             view.fig.canvas.flush_events()
 
 
-def stop_view(view):
+def advance_until_stopped(*views):
+    to_advance = list(views)
+    while to_advance:
+        for view in to_advance:
+            try:
+                advance_frames(view, 1)
+            except AttributeError:
+                # event_source has been removed, meaning the animation was stopped
+                to_advance.remove(view)
+            except RuntimeError:
+                # thread did not join
+                continue
+
+
+def stop_view(*views, in_process):
+    if len(views) != 1:
+        # need to hack a bit to get the linked views to stop
+        views[0].stop_event.set()
+        if not in_process and not is_using_mpl_gui_backend(views[0].fig):
+            advance_until_stopped(*views)
+        else:
+            time.sleep(100e-3)
+
     try:
-        view.stop()
-    except RuntimeError:
-        # Thread did not join. Try to trigger event loop once.
-        advance_frames(view, 1)
-        view.stop()
+        views[0].stop()
+    except AttributeError:
+        # ???
+        views[0].stop()
 
 
-def close_figure(fig):
-    if not is_using_mpl_gui_backend(fig):
+def close_view(*views, in_process=False):
+    if in_process:
+        views[0].close_event.set()
+        time.sleep(100e-3)
+        return
+
+    stop_view(*views, in_process=in_process)
+
+    if not is_using_mpl_gui_backend(fig := views[0].fig):
         # Need to manually trigger the close event because the event loop isn't running
         fig.canvas.callbacks.process('close_event', CloseEvent('close_event', fig.canvas))
 
@@ -53,11 +81,14 @@ def close_figure(fig):
     plt.close(fig)
 
 
-def statement_timed_out(stmt: Callable[[], bool], timeout) -> bool:
+def statement_timed_out(stmt: Callable[[], bool], obj, timeout) -> bool:
     try:
         with misc.timeout(timeout, raise_exc=True) as exceeded:
             while not stmt() and not exceeded:
-                time.sleep(10e-3)
+                if hasattr(obj, 'fig'):
+                    obj.fig.canvas.start_event_loop(10e-3)
+                else:
+                    time.sleep(10e-3)
     except TimeoutError:
         return True
     else:
@@ -89,7 +120,7 @@ def started(spectrometer, plot_timetrace, in_process, in_gitlab_ci):
     if not in_process:
         for view in views:
             start_animation(view.fig)
-            advance_frames(view, random.randint(1, 10))
+            advance_frames(view, random.randint(10, 20))
 
     with misc.timeout(30, raise_exc=True) as exceeded:
         while not all(view.is_running() for view in views) and not exceeded:
@@ -97,43 +128,25 @@ def started(spectrometer, plot_timetrace, in_process, in_gitlab_ci):
 
     yield views
 
-    for view in views:
-        view.stop()
-        if in_process:
+    stop_view(*views, in_process=in_process)
+    close_view(*views, in_process=in_process)
+    if in_process:
+        for view in views:
             view.process.terminate()
-        else:
-            close_figure(view.fig)
 
 
 @pytest.fixture
 def stopped(started: list[LiveViewT], in_process: bool):
-    view = random.choice(started)
-    stop_view(view)
-
-    if not in_process and len(started) > 1:
-        advance_frames(started[1 - started.index(view)], 1)
-
-    stopped = started
-    return stopped
+    random.shuffle(views := started)
+    stop_view(*views, in_process=in_process)
+    return views
 
 
 @pytest.fixture
 def closed(started: list[LiveViewT], in_process: bool):
-    view = random.choice(started)
-
-    if in_process:
-        view.close_event.set()
-    else:
-        close_figure(view.fig)
-
-    if not in_process and len(started) > 1:
-        advance_frames(started[1 - started.index(view)], 1)
-    else:
-        # Give the process time to process all events
-        time.sleep(250e-3)
-
-    closed = started
-    yield closed
+    random.shuffle(views := started)
+    close_view(*views, in_process=in_process)
+    yield views
 
 
 def test_started(spectrometer, started, plot_timetrace, in_process):
@@ -157,9 +170,9 @@ def test_started(spectrometer, started, plot_timetrace, in_process):
             assert isinstance(views[0], LiveViewBase.LiveViewProxy)
 
     for view in views:
-        assert not statement_timed_out(lambda: view.is_running() is True, timeout=1)
-        assert not statement_timed_out(lambda: view.data_thread.is_alive(), timeout=1)
-        assert not statement_timed_out(lambda: not view.stop_event.is_set(), timeout=1)
+        assert not statement_timed_out(lambda: view.is_running() is True, view, timeout=1)
+        assert not statement_timed_out(lambda: view.data_thread.is_alive(), view, timeout=1)
+        assert not statement_timed_out(lambda: not view.stop_event.is_set(), view, timeout=1)
 
 
 @pytest.mark.parametrize("view_state", ["stopped", "closed"])
@@ -167,9 +180,9 @@ def test_finished(spectrometer, view_state, request, plot_timetrace, in_process,
     """Test the state of view(s) and spectrometer after stopping and closing."""
     views = request.getfixturevalue(view_state)
 
-    assert not spectrometer.acquiring
+    assert not statement_timed_out(lambda: not spectrometer.acquiring, spectrometer, timeout=1)
 
     for view in views:
-        assert not statement_timed_out(lambda: view.is_running() is None, timeout=10)
-        assert not statement_timed_out(lambda: not view.data_thread.is_alive(), timeout=10)
-        assert not statement_timed_out(lambda: view.stop_event.is_set(), timeout=10)
+        assert not statement_timed_out(lambda: view.is_running() is None, view, timeout=10)
+        assert not statement_timed_out(lambda: not view.data_thread.is_alive(), view, timeout=10)
+        assert not statement_timed_out(lambda: view.stop_event.is_set(), view, timeout=10)