Add Python-based WebSockets tests

1. Create WS tests with the same structure as basic.py
2. Add JSON tests
3. Add "raw" tests

tests/requirements.txt

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+websocket-client>=1.1.0

tests/ws-tests.py

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+#!/usr/bin/env python3
+
+import abc
+import json
+import os
+import unittest
+import uuid
+from websocket import create_connection
+
+host = os.getenv('WEBDIS_HOST', '127.0.0.1')
+port = int(os.getenv('WEBDIS_PORT', 7379))
+
+class TestWebdis(unittest.TestCase):
+	def setUp(self) -> None:
+		self.ws = create_connection(f'ws://{host}:{port}/.{self.format()}')
+
+	def tearDown(self) -> None:
+		self.ws.close()
+
+	def exec(self, cmd, *args):
+		self.ws.send(self.serialize(cmd, *args))
+		return self.deserialize(self.ws.recv())
+
+	def clean_key(self):
+		"""Returns a key that was just deleted"""
+		key = str(uuid.uuid4())
+		self.exec('DEL', key)
+		return key
+
+	@abc.abstractmethod
+	def format(self):
+		"""Returns the format to use (added after a dot to the WS URI)"""
+		return
+	
+	@abc.abstractmethod
+	def serialize(self, cmd):
+		"""Serializes a command according to the format being tested"""
+		return
+
+	@abc.abstractmethod
+	def deserialize(self, response):
+		"""Deserializes a response according to the format being tested"""
+		return
+
+
+class TestJson(TestWebdis):
+	def format(self):
+		return 'json'
+
+	def serialize(self, cmd, *args):
+		return json.dumps([cmd] + list(args))
+
+	def deserialize(self, response):
+		return json.loads(response)
+
+	def test_ping(self):
+		self.assertEqual(self.exec('PING'), {'PING': [True, 'PONG']})
+
+	def test_multiple_messages(self):
+		key = self.clean_key()
+		n = 100
+		for i in range(n):
+			lpush_response = self.exec('LPUSH', key, f'value-{i}')
+			self.assertEqual(lpush_response, {'LPUSH': i + 1})
+		self.assertEqual(self.exec('LLEN', key), {'LLEN': n})
+
+
+class TestRaw(TestWebdis):
+	def format(self):
+		return 'raw'
+
+	def serialize(self, cmd, *args):
+		buffer = f"*{1 + len(args)}\r\n${len(cmd)}\r\n{cmd}\r\n"
+		for arg in args:
+			buffer += f"${len(arg)}\r\n{arg}\r\n"
+		return buffer
+
+	def deserialize(self, response):
+		return response # we'll just assert using the raw protocol
+
+	def test_ping(self):
+		self.assertEqual(self.exec('PING'), "+PONG\r\n")
+
+	def test_get_set(self):
+		key = self.clean_key()
+		value = str(uuid.uuid4())
+		not_found_response = self.exec('GET', key)
+		self.assertEqual(not_found_response, "$-1\r\n")  # Redis protocol response for "not found"
+		set_response = self.exec('SET', key, value)
+		self.assertEqual(set_response, "+OK\r\n")
+		get_response = self.exec('GET', key)
+		self.assertEqual(get_response, f"${len(value)}\r\n{value}\r\n")
+
+
+if __name__ == '__main__':
+	unittest.main()