test: add test suites of env variables loader

tests/test_env_opts.py

@@ -0,0 +1,138 @@
+#!/usr/bin/env python3
+# -*- coding: utf-8 -*-
+
+import os
+import pytest
+from src import boot
+
+
+@pytest.fixture(autouse=True)
+def env_cleanup():
+    """
+    Clean up the environment variables before each test.
+    """
+    boot.init_opts()
+    env_backup = os.environ.copy()
+    os.environ.clear()
+    os.environ['UNKNOWN'] = 'unknown_value'
+    os.environ['ANOTHER_UNKNOWN'] = 'something'
+    yield
+    os.environ.update(env_backup)
+
+
+def test_env_empty():
+    """
+    Test environment variables in the empty case.
+    """
+    options = boot.load_from_env()
+    assert isinstance(options, dict) and not options
+
+
+@pytest.mark.parametrize(
+    'name, env_tag',
+    [
+        ('port', 'PORT'),
+        ('max_username', 'MAX_USERNAME'),
+        ('max_chat_message', 'MAX_CHAT_MESSAGE'),
+    ],
+)
+def test_env_int(name: str, env_tag: str):
+    """
+    Test environment variables for single integer option.
+    """
+    os.environ[env_tag] = '0'
+    assert boot.load_from_env() == {name: 0}
+
+    os.environ[env_tag] = '42'
+    assert boot.load_from_env() == {name: 42}
+
+
+@pytest.mark.parametrize(
+    'name, env_tag',
+    [
+        ('config', 'CONFIG'),
+        ('password', 'PASSWORD'),
+        ('motd', 'MOTD'),
+        ('salt', 'SALT'),
+        ('listen_ipv4', 'LISTEN_IPV4'),
+        ('listen_ipv6', 'LISTEN_IPV6'),
+    ],
+)
+def test_env_str(name: str, env_tag: str):
+    """
+    Test environment variables for single string option.
+    """
+    os.environ[env_tag] = ''
+    assert boot.load_from_env() == {name: ''}
+
+    os.environ[env_tag] = 'TeSt \n0123456789\t'
+    assert boot.load_from_env() == {name: 'TeSt \n0123456789\t'}
+
+
+@pytest.mark.parametrize(
+    'name, env_tag',
+    [
+        ('random_salt', 'RANDOM_SALT'),
+        ('isolate_rooms', 'ISOLATE_ROOMS'),
+        ('disable_chat', 'DISABLE_CHAT'),
+        ('disable_ready', 'DISABLE_READY'),
+        ('enable_stats', 'ENABLE_STATS'),
+        ('enable_tls', 'ENABLE_TLS'),
+        ('persistent', 'PERSISTENT'),
+    ],
+)
+def test_env_bool(name: str, env_tag: str):
+    """
+    Test environment variables for single boolean option.
+    """
+    for val in ['TRUE', 'TrUe', 'true', 'ON', 'on']:  # TODO: allow `1`
+        os.environ[env_tag] = val
+        assert boot.load_from_env() == {name: True}
+
+    for val in ['FALSE', 'FaLsE', 'false', 'OFF', 'off', '0']:
+        os.environ[env_tag] = val
+        assert boot.load_from_env() == {name: False}
+
+
+def test_env_full():
+    """
+    Test all environment variable options.
+    """
+    env_data = {
+        'CONFIG': 'config.yml',
+        'PORT': '8999',
+        'PASSWORD': 'PASSWD',
+        'MOTD': 'MESSAGE',
+        'SALT': 'SALT',
+        'RANDOM_SALT': 'OFF',
+        'ISOLATE_ROOMS': 'ON',
+        'DISABLE_CHAT': 'OFF',
+        'DISABLE_READY': 'ON',
+        'ENABLE_STATS': 'OFF',
+        'ENABLE_TLS': 'ON',
+        'PERSISTENT': 'OFF',
+        'MAX_USERNAME': '120',
+        'MAX_CHAT_MESSAGE': '240',
+        'LISTEN_IPV4': '127.0.0.1',
+        'LISTEN_IPV6': '::1',
+    }
+    excepted_opts = {
+        'config': 'config.yml',
+        'port': 8999,
+        'password': 'PASSWD',
+        'motd': 'MESSAGE',
+        'salt': 'SALT',
+        'random_salt': False,
+        'isolate_rooms': True,
+        'disable_chat': False,
+        'disable_ready': True,
+        'enable_stats': False,
+        'enable_tls': True,
+        'persistent': False,
+        'max_username': 120,
+        'max_chat_message': 240,
+        'listen_ipv4': '127.0.0.1',
+        'listen_ipv6': '::1',
+    }
+    os.environ.update(env_data)
+    assert boot.load_from_env() == excepted_opts

tests/test_init_opts.py

@@ -114,9 +114,9 @@ def test_init_opts():
     """
     Test initialization and idempotency of the init_opts function.
     """
-    assert not boot.ARG_OPTS
-    assert not boot.ENV_OPTS
-    assert not boot.CFG_OPTS
+    boot.ARG_OPTS.clear()
+    boot.ENV_OPTS.clear()
+    boot.CFG_OPTS.clear()
 
     for _ in range(2):
         boot.init_opts()  # run twice to verify idempotency