Increase test coverage from 70% to 93%

Also see discovered camera release bug while testing, refs #14

Makefile

@@ -94,7 +94,7 @@ release/upload:
 	$(TWINE) upload dist/*
 
 clean: release/clean docs/clean
-	py3clean src/
+	py3clean .
 	find . -type d -name "__pycache__" -exec rm -r {} +
 	find . -type d -name "*.egg-info" -exec rm -r {} +
 	rm -rf htmlcov/

README.md

@@ -40,7 +40,7 @@ Notes:
 [xcamera is available on PyPI](https://pypi.org/project/xcamera/).
 Therefore it can be installed via `pip`.
 ```sh
-pip3 install --user xcamera
+pip3 install xcamera
 ```
 Once installed, the demo should be available in your `PATH` and can be ran from the command line.
 ```sh

tests/kivy_garden/xcamera/test_main.py

@@ -0,0 +1,38 @@
+from threading import Thread
+from unittest import mock
+
+from kivy.app import App
+from kivy.clock import Clock
+
+from kivy_garden.xcamera.main import CameraApp, main
+from tests.test_main import camera_release_workaround, patch_core_camera
+
+
+def patch_picture_taken():
+    return mock.patch('kivy_garden.xcamera.main.CameraApp.picture_taken')
+
+
+class TestMain:
+    """
+    Tests the `main` module.
+    """
+
+    def test_picture_taken(self):
+        """
+        Checks the `picture_taken()` listener gets called on the running app.
+        """
+        app_thread = Thread(target=main)
+        app_thread.start()
+        app = App.get_running_app()
+        filename = mock.sentinel
+        Clock.schedule_once(
+            lambda dt: app.root.ids.xcamera.dispatch(
+                'on_picture_taken', filename))
+        # makes sure app thread is gracefully stopped before asserting
+        app.stop()
+        with patch_picture_taken() as m_picture_taken, patch_core_camera():
+            app_thread.join()
+        camera_release_workaround(app)
+        assert type(app) == CameraApp
+        assert m_picture_taken.mock_calls == [
+            mock.call(app.root.ids.xcamera, filename)]

tests/test_main.py

@@ -1,14 +1,52 @@
+import os
+from threading import Thread
 from unittest import mock
 
+from kivy.app import App
+
+from kivy_garden.xcamera.main import CameraApp
 from main import main
 
 
+def camera_release_workaround(app):
+    """
+    Upstream bug workaround, refs:
+    https://github.com/kivy-garden/xcamera/issues/14
+    """
+    app.root.ids.xcamera._camera._device.release()
+
+
+def get_camera_class():
+    """
+    Continuous integration providers don't have a camera available.
+    """
+    if os.environ.get('CI', False):
+        Camera = None
+    else:
+        from kivy.core.camera import Camera
+    return Camera
+
+
+def patch_core_camera():
+    Camera = get_camera_class()
+    return mock.patch('kivy.uix.camera.CoreCamera', wraps=Camera)
+
+
 class TestMain:
     """
     Tests the `main` module.
     """
 
     def test_main(self):
-        with mock.patch('kivy_garden.xcamera.main.CameraApp.run') as m_play:
-            main()
-        assert m_play.mock_calls == [mock.call()]
+        """
+        Checks the main starts the app properly.
+        """
+        app_thread = Thread(target=main)
+        app_thread.start()
+        app = App.get_running_app()
+        # makes sure app thread is gracefully stopped before asserting
+        app.stop()
+        with patch_core_camera():
+            app_thread.join()
+        camera_release_workaround(app)
+        assert type(app) == CameraApp

tox.ini

@@ -11,8 +11,7 @@ passenv = DISPLAY
 deps =
 	-r{toxinidir}/requirements.txt
 	-r{toxinidir}/requirements/requirements-test.txt
-commands =
-	pytest --cov src/ tests/
+commands = pytest --cov src/ tests/
 
 [testenv:pep8]
 commands = flake8 {env:SOURCES}