tests: Auto-discover applications and try to switch to them

Currently `make check` doesn't test any not-default applications.
Fix this by automatically discovering constructors and ensure that the
application can be started and stopped without generating an exception.

Signed-off-by: Daniel Thompson <daniel@redfelineninja.org.uk>

wasp/boards/simulator/conftest.py

@@ -0,0 +1,25 @@
+import glob
+import importlib
+import inspect
+import pytest
+
+def discover_app_constructors():
+    apps = []
+
+    globs = glob.glob('wasp/apps/*.py')
+    names = [ g[5:-3].replace('/', '.') for g in globs ]
+    modules = [ importlib.import_module(n) for n in names ]
+
+    for m in modules:
+        for sym in m.__dict__.keys():
+            if len(sym) > 3 and sym[-3:] == 'App':
+                constructor = m.__dict__[sym]
+                sig = inspect.signature(constructor)
+                if len(sig.parameters) == 0:
+                    apps.append(constructor)
+
+    return apps
+
+def pytest_generate_tests(metafunc):
+    if 'constructor' in metafunc.fixturenames:
+         metafunc.parametrize('constructor', discover_app_constructors())

wasp/boards/simulator/test_smoke.py

@@ -48,6 +48,30 @@ def test_app(system, name):
         system.step()
     system.switch(system.quick_ring[0])
 
+def test_constructor(system, constructor):
+    # Special case for the notification app
+    if 'NotificationApp' in str(constructor):
+         wasp.system.notify(wasp.watch.rtc.get_uptime_ms(),
+             {
+                 "src":"testcase",
+                 "title":"A test",
+                 "body":"This is a long message containingaverylongwordthatdoesnotfit and lots of other contents as well."
+             })
+
+    try:
+        system.switch(constructor())
+        system.step()
+        system.step()
+        wasp.watch.touch.press(120, 120)
+        system.step()
+        system.step()
+        system.switch(system.quick_ring[0])
+    except FileNotFoundError:
+        # Some apps intend to generate exceptions during the constructor
+        # if they don't have required files available
+        if 'HaikuApp' not in str(constructor):
+            raise
+
 def test_stopwatch(system):
     system.switch(system.apps['Timer'])