Add initial tests for configuration reloading

Currently only:
- Test for not reloading configuration if run_once is not True
- Test for reloading main configuration and other configurations triggered by 
  changes in main configuration file

TODO: tests for all other configuration files reloading (colors, colorscheme, 
      theme).

tests/test_config_reload.py

@@ -0,0 +1,212 @@
+# vim:fileencoding=utf-8:noet
+
+import powerline as powerline_module
+import time
+from powerline.renderer import Renderer
+from tests import TestCase
+from tests.lib import replace_item
+from copy import deepcopy
+from threading import Lock
+
+
+class Watcher(object):
+	events = set()
+
+	def watch(self, file):
+		pass
+
+	def __call__(self, file):
+		if file in self.events:
+			self.events.remove(file)
+			return True
+		return False
+
+	def _add(self, file):
+		self.events.add(file)
+
+
+class Logger(object):
+	def __init__(self):
+		self.messages = []
+		self.lock = Lock()
+
+	def _add_msg(self, msg):
+		with self.lock:
+			self.messages.append(msg)
+
+	def _pop_msgs(self):
+		with self.lock:
+			r = self.messages
+			self.messages = []
+		return r
+
+	def __getattr__(self, attr):
+		return self._add_msg
+
+
+config = {
+	'config': {
+		'common': {
+			'dividers': {
+			},
+			'spaces': 0,
+		},
+		'ext': {
+			'test': {
+				'theme': 'default',
+				'colorscheme': 'default',
+			},
+		},
+	},
+	'colors': {
+		'colors': {
+		},
+		'gradients': {
+		},
+	},
+	'colorschemes/test/default': {
+		'groups': {
+		},
+	},
+	'themes/test/default': {
+		'segments': {
+		},
+	},
+}
+
+
+access_log = []
+access_lock = Lock()
+
+
+def load_json_config(config_file_path, *args, **kwargs):
+	global access_log
+	with access_lock:
+		access_log.append(config_file_path)
+	try:
+		return deepcopy(config[config_file_path])
+	except KeyError:
+		raise IOError(config_file_path)
+
+
+def find_config_file(search_paths, config_file):
+	return config_file
+
+
+class SimpleRenderer(Renderer):
+	def hlstyle(self, fg=None, bg=None, attr=None):
+		return '<{fg} {bg} {attr}>'.format(fg=fg, bg=bg, attr=attr)
+
+
+class TestPowerline(powerline_module.Powerline):
+	@staticmethod
+	def get_local_themes(local_themes):
+		return local_themes
+
+
+renderer = SimpleRenderer
+
+
+def get_powerline(**kwargs):
+	return TestPowerline(ext='test', renderer_module='tests.test_config_reload', interval=0, logger=Logger(), **kwargs)
+
+
+# Minimum sleep time on my system is 0.000001, otherwise it fails to update 
+# config
+# This sleep time is 100 times bigger
+def sleep(interval=0.0001):
+	time.sleep(interval)
+
+
+def add_watcher_events(*args):
+	Watcher.events.update(args)
+	sleep()
+
+
+class TestConfigReload(TestCase):
+	def assertAccessEvents(self, *args):
+		global access_log
+		with access_lock:
+			self.assertEqual(set(access_log), set(args))
+			access_log = []
+
+	def test_noreload(self):
+		with get_powerline(run_once=True) as p:
+			with replace_item(globals(), 'config', deepcopy(config)):
+				self.assertEqual(p.render(), '<None None None>')
+				self.assertAccessEvents('config', 'colors', 'colorschemes/test/default', 'themes/test/default')
+				config['config']['common']['spaces'] = 1
+				add_watcher_events('config')
+				# When running once thread should not start
+				self.assertAccessEvents()
+				self.assertEqual(p.render(), '<None None None>')
+				self.assertEqual(p.logger._pop_msgs(), [])
+
+	def test_reload_main(self):
+		with get_powerline(run_once=False) as p:
+			with replace_item(globals(), 'config', deepcopy(config)):
+				self.assertEqual(p.render(), '<None None None>')
+				self.assertAccessEvents('config', 'colors', 'colorschemes/test/default', 'themes/test/default')
+
+				config['config']['common']['spaces'] = 1
+				add_watcher_events('config')
+				self.assertAccessEvents('config')
+				self.assertEqual(p.render(), '<None None None>')
+				self.assertEqual(p.logger._pop_msgs(), [])
+
+				config['config']['ext']['test']['theme'] = 'new'
+				add_watcher_events('config')
+				self.assertAccessEvents('config', 'themes/test/new')
+				self.assertEqual(p.render(), '<None None None>')
+				# It should normally handle file missing error
+				self.assertEqual(p.logger._pop_msgs(), ['test:Failed to create renderer: themes/test/new'])
+
+				config['config']['ext']['test']['theme'] = 'default'
+				add_watcher_events('config')
+				self.assertAccessEvents('config', 'themes/test/default')
+				self.assertEqual(p.render(), '<None None None>')
+				self.assertEqual(p.logger._pop_msgs(), [])
+
+				config['config']['ext']['test']['colorscheme'] = 'new'
+				add_watcher_events('config')
+				self.assertAccessEvents('config', 'colorschemes/test/new')
+				self.assertEqual(p.render(), '<None None None>')
+				# It should normally handle file missing error
+				self.assertEqual(p.logger._pop_msgs(), ['test:Failed to create renderer: colorschemes/test/new'])
+
+				config['config']['ext']['test']['colorscheme'] = 'default'
+				add_watcher_events('config')
+				self.assertAccessEvents('config', 'colorschemes/test/default')
+				self.assertEqual(p.render(), '<None None None>')
+				self.assertEqual(p.logger._pop_msgs(), [])
+
+				self.assertEqual(p.renderer.local_themes, None)
+				config['config']['ext']['test']['local_themes'] = 'something'
+				add_watcher_events('config')
+				self.assertAccessEvents('config')
+				self.assertEqual(p.render(), '<None None None>')
+				self.assertEqual(p.logger._pop_msgs(), [])
+				self.assertEqual(p.renderer.local_themes, 'something')
+
+
+replaces = {
+	'watcher': Watcher(),
+	'load_json_config': load_json_config,
+	'find_config_file': find_config_file,
+}
+
+
+def swap_attributes():
+	global replaces
+	for attr, val in replaces.items():
+		old_val = getattr(powerline_module, attr)
+		setattr(powerline_module, attr, val)
+		replaces[attr] = old_val
+
+
+tearDownModule = setUpModule = swap_attributes
+
+
+if __name__ == '__main__':
+	from tests import main
+	main()