Made tests in PyCharm work

.run/All Tests.run.xml

@@ -0,0 +1,16 @@
+<component name="ProjectRunConfigurationManager">
+  <configuration default="false" name="All Tests" type="tests" factoryName="Autodetect">
+    <module name="input-remapper" />
+    <option name="INTERPRETER_OPTIONS" value="" />
+    <option name="PARENT_ENVS" value="true" />
+    <option name="SDK_HOME" value="" />
+    <option name="WORKING_DIRECTORY" value="$PROJECT_DIR$" />
+    <option name="IS_MODULE_SDK" value="true" />
+    <option name="ADD_CONTENT_ROOTS" value="true" />
+    <option name="ADD_SOURCE_ROOTS" value="true" />
+    <option name="_new_additionalArguments" value="&quot;&quot;" />
+    <option name="_new_target" value="&quot;$PROJECT_DIR$/tests/testcases&quot;" />
+    <option name="_new_targetType" value="&quot;PATH&quot;" />
+    <method v="2" />
+  </configuration>
+</component>

tests/__init__.py

@@ -0,0 +1,2 @@
+# make sure patches are loaded
+import tests.test

tests/test.py

@@ -23,6 +23,9 @@
 import os
 import sys
 
+# the working directory should be the project root
+assert not os.getcwd().endswith("tests")
+
 # make sure the "tests" module visible
 sys.path.append(os.getcwd())
 if __name__ == "__main__":
@@ -51,10 +54,7 @@ gi.require_version("Gtk", "3.0")
 gi.require_version("GLib", "2.0")
 gi.require_version("GtkSource", "4")
 
-from xmodmap import xmodmap
-
-assert not os.getcwd().endswith("tests")
-
+from tests.xmodmap import xmodmap
 
 os.environ["UNITTEST"] = "1"
 
@@ -660,9 +660,10 @@ def spy(obj, name):
     return patch.object(obj, name, wraps=obj.__getattribute__(name))
 
 
-def main():
-    cleanup()
+cleanup()
 
+
+def main():
     modules = sys.argv[1:]
     # discoverer is really convenient, but it can't find a specific test
     # in all of the available tests like unittest.main() does...,