Рефакторинг парсера команд

command_parser/__init__.py

@@ -1,13 +1,25 @@
+import re
+
+
 class CommandParser:
     @staticmethod
     def parse(command_string):
-        parsed_command = command_string.split('_')
+
+        if not command_string:
+            raise ValueError("Empty command received!")
+
+        if not isinstance(command_string, str):
+            raise ValueError("Command must be a sting!")
+
+        if re.search('[^a-zA-Z0-9_\-]', command_string):
+            raise ValueError('Only [a-zA-Z0-9_\-] allowed')
+
+        if re.search('^GET_.*', command_string):
+            parsed_command = command_string.split('_', 1)
 
             command = parsed_command[0]
             value = parsed_command[1]
 
-        match command:
-            case 'GET':
             return {'command': command, 'value': value}
-            case _:
-                raise ValueError("Unknown command: "+command)
+        else:
+            raise ValueError("Unknown command: " + command_string)

tests/test_command_parser.py

@@ -0,0 +1,54 @@
+import unittest
+from command_parser import CommandParser
+
+
+class TestCommandParser(unittest.TestCase):
+    def test_empty_line(self):
+        with self.assertRaises(ValueError) as context:
+            CommandParser.parse('')
+
+        self.assertEqual('Empty command received!', str(context.exception))
+
+    def test_unknown_command(self):
+        with self.assertRaises(ValueError) as context:
+            CommandParser.parse('REALLY_UNKNOWN_COMMAND')
+
+        self.assertEqual('Unknown command: REALLY_UNKNOWN_COMMAND', str(context.exception))
+
+    def test_parse_get_command(self):
+        result = CommandParser.parse('GET_A')
+
+        self.assertEqual(result, {'command': 'GET', 'value': 'A'})
+
+    def test_parse_get_command_w_dual_underlines(self):
+        result = CommandParser.parse('GET_A_B')
+
+        self.assertEqual(result, {'command': 'GET', 'value': 'A_B'})
+
+    def test_invalid_command(self):
+        with self.assertRaises(ValueError) as context:
+            CommandParser.parse('NOT_GET_A')
+
+        self.assertEqual('Unknown command: NOT_GET_A', str(context.exception))
+
+    def test_invalid_command_string_type(self):
+        with self.assertRaises(ValueError) as context:
+            CommandParser.parse(b'some_cmd')
+
+        self.assertEqual('Command must be a sting!', str(context.exception))
+
+    def test_not_allowed_symbols_in_command_string(self):
+        with self.assertRaises(ValueError) as context:
+            CommandParser.parse('GET_!')
+
+        self.assertEqual('Only [a-zA-Z0-9_\-] allowed', str(context.exception))
+
+    def test_not_allowed_newline_in_command_string(self):
+        with self.assertRaises(ValueError) as context:
+            CommandParser.parse("GET_A\nGET_B")
+
+        self.assertEqual('Only [a-zA-Z0-9_\-] allowed', str(context.exception))
+
+
+if __name__ == '__main__':
+    unittest.main()