Add some initial tests.

README.md

@@ -41,3 +41,16 @@ Make sure you have **Python 3.4** or better on your computer.
 To install pyno you must run ```pip install .``` from this directory.
 Pyno's dependencies `pyglet` and `pyperclip` are going to be installed automatically.
 Then run ```pyno``` in a console.
+
+# How to modify
+
+To develop/modify code, you can install Pyno in "developer mode" by running `pip install -e .` in the Pyno directory. 
+This runs setup.py and installs a link to the `pyno` directory, as if it were normally installed.
+
+To run the tests, you need `pytest`  installed. 
+You run `pytest` in the root directory of the repository. 
+It will discover the tests in the `tests` directory and run them on the installed package. 
+You will see a couple of flashing windows when they get instantiated.
+
+If you have (on Linux) `xvfb` and the pytest plugin `pytest-xvfb` installed, the tests should automatically be run on the virtual framebuffer, so no windows should become visible. 
+If this for some reason does not work, invoking pytest via `xvfb-run pytest` should do the trick.

pyno/window.py

@@ -451,6 +451,13 @@ def paste_nodes(self):
 
 def app_run():
     print('Loading...')
+    window = get_window()  # Not using this for anything
+    pyglet.options['debug_gl'] = False  # performance boost?
+    # profile.run('pyglet.app.run()', sort=1)
+    pyglet.app.run()
+
+
+def get_window():
     config = pyglet.gl.Config(double_buffer=True, depth_size=0,
                               stencil_size=0, aux_buffers=0,
                               samples=1)
@@ -459,6 +466,4 @@ def app_run():
     except:
         # if config is crashed run more default one
         pwindow = PynoWindow(pyglet.gl.Config(), filename='.auto-saved.pn')
-    pyglet.options['debug_gl'] = False  # performance boost?
-    # profile.run('pyglet.app.run()', sort=1)
-    pyglet.app.run()
+    return pwindow

setup.py

@@ -43,7 +43,7 @@
     packages=find_packages(exclude=['docs', 'tests']),
     install_requires=['pyglet', 'pyperclip'],
     extras_require={
-        'test': ['pytest', 'coverage'],
+        'test': ['pytest'],
     },
     package_data={
         'pyno': ['imgs/*.png', 'examples/*.pn'],

tests/conftest.py

@@ -0,0 +1,11 @@
+"""This contains e.g. fixtures that supply reusable elements."""
+
+import pytest
+
+import pyno.window
+
+
+@pytest.fixture
+def window():
+    """Supply a window, as that will probably be useful quite often."""
+    return pyno.window.get_window()

tests/test_element.py

@@ -0,0 +1,3 @@
+"""Tests for pyno.element"""
+
+pass

tests/test_window.py

@@ -0,0 +1,17 @@
+"""Tests for pyno.window"""
+import pyglet
+
+from pyno import window
+
+
+def test_app_run():
+    pyglet.clock.schedule_once(lambda x: pyglet.app.exit(), 0.1)
+    window.app_run()
+
+
+def test_get_window(window):
+    # Check some meaningful things
+    assert window.caption == 'Pyno'
+    assert window.active_nodes == []
+
+