fix: add configuration tests and settings validation

.vscode/settings.json

@@ -0,0 +1,3 @@
+{
+  "python.terminal.useEnvFile": true
+}

src/python_response_time/core/config.py

@@ -12,7 +12,6 @@ class Settings(BaseSettings):
     LOG_TO_STDOUT: Annotated[
         bool, Field(description="Whether to log to stdout (console)", strict=False)
     ] = True
-
     TARGET_URL: Annotated[
         list[str], Field(description="List of target endpoints for benchmarking")
     ] = ["https://httpbin.org/get", "https://httpbin.org/status/200"]

tests/test_config.py

@@ -0,0 +1,219 @@
+"""Unit tests for config.py in python_response_time.core."""
+
+from typing import Any, cast
+
+import pytest
+from pydantic import ValidationError
+
+from python_response_time.core import config
+
+
+def test_default_values(monkeypatch):
+    """Test default configuration values."""
+    monkeypatch.delenv("TARGET_URL", raising=False)
+    monkeypatch.delenv("NUM_REQUESTS", raising=False)
+    monkeypatch.delenv("CONNECT_TIMEOUT", raising=False)
+    monkeypatch.delenv("READ_TIMEOUT", raising=False)
+    monkeypatch.delenv("REQUEST_DELAY", raising=False)
+    monkeypatch.delenv("LOG_LEVEL", raising=False)
+    monkeypatch.delenv("VERIFY_SSL", raising=False)
+    monkeypatch.delenv("LOG_TO_STDOUT", raising=False)
+
+    class TestSettings(config.Settings):
+        model_config = config.SettingsConfigDict(
+            env_file=None,
+        )
+
+    s = TestSettings()
+
+    assert s.LOG_TO_STDOUT is True
+    assert s.TARGET_URL == [
+        "https://httpbin.org/get",
+        "https://httpbin.org/status/200",
+    ]
+    assert s.NUM_REQUESTS == 10
+    assert s.CONNECT_TIMEOUT == 1.0
+    assert s.READ_TIMEOUT == 3.0
+    assert s.REQUEST_DELAY == 2.0
+    assert s.LOG_LEVEL == "INFO"
+    assert s.VERIFY_SSL is True
+
+
+def test_app_settings_instance():
+    """Test that the module-level settings object exists."""
+    assert isinstance(config.app_settings, config.Settings)
+
+
+def test_env_override_num_requests(monkeypatch):
+    """Test environment variable override for integer values."""
+    monkeypatch.setenv("NUM_REQUESTS", "42")
+
+    s = config.Settings()
+
+    assert s.NUM_REQUESTS == 42
+
+
+@pytest.mark.parametrize(
+    ("env_value", "expected"),
+    [
+        ("true", True),
+        ("false", False),
+        ("1", True),
+        ("0", False),
+        ("yes", True),
+        ("no", False),
+    ],
+)
+def test_bool_env_parsing(monkeypatch, env_value, expected):
+    """Test boolean parsing from environment variables."""
+    monkeypatch.setenv("VERIFY_SSL", env_value)
+
+    s = config.Settings()
+
+    assert s.VERIFY_SSL is expected
+
+
+def test_log_to_stdout_env_parsing(monkeypatch):
+    """Test LOG_TO_STDOUT boolean parsing from environment variable."""
+    monkeypatch.setenv("LOG_TO_STDOUT", "true")
+
+    s = config.Settings()
+
+    assert s.LOG_TO_STDOUT is True
+
+
+def test_target_url_env_override(monkeypatch):
+    """Test TARGET_URL parsing from environment variable."""
+    monkeypatch.setenv(
+        "TARGET_URL",
+        '["https://example.com", "https://test.com"]',
+    )
+
+    s = config.Settings()
+
+    assert s.TARGET_URL == [
+        "https://example.com",
+        "https://test.com",
+    ]
+
+
+@pytest.mark.parametrize(
+    ("field", "value"),
+    [
+        ("NUM_REQUESTS", 0),
+        ("NUM_REQUESTS", -1),
+        ("NUM_REQUESTS", 1_000_001),
+        ("CONNECT_TIMEOUT", 0),
+        ("CONNECT_TIMEOUT", -1),
+        ("CONNECT_TIMEOUT", 121),
+        ("READ_TIMEOUT", 0),
+        ("READ_TIMEOUT", -5),
+        ("READ_TIMEOUT", 121),
+        ("REQUEST_DELAY", 0),
+        ("REQUEST_DELAY", -1),
+        ("REQUEST_DELAY", 61),
+    ],
+)
+def test_invalid_numeric_values(field, value):
+    """Test numeric validation boundaries."""
+    with pytest.raises(ValidationError):
+        config.Settings(**{field: value})
+
+
+@pytest.mark.parametrize(
+    "value",
+    [
+        "debug",
+        "trace",
+        "INVALID",
+        "",
+        "info",
+        "warn",
+    ],
+)
+def test_invalid_log_level(value):
+    """Test invalid LOG_LEVEL values."""
+    with pytest.raises(ValidationError):
+        config.Settings(LOG_LEVEL=value)
+
+
+@pytest.mark.parametrize(
+    "value",
+    [
+        "DEBUG",
+        "INFO",
+        "WARNING",
+        "ERROR",
+        "CRITICAL",
+    ],
+)
+def test_valid_log_levels(value):
+    """Test valid LOG_LEVEL values."""
+    s = config.Settings(LOG_LEVEL=value)
+
+    assert s.LOG_LEVEL == value
+
+
+def test_invalid_env_value(monkeypatch):
+    """Test invalid environment variable values raise errors."""
+    monkeypatch.setenv("NUM_REQUESTS", "not-an-int")
+
+    with pytest.raises(ValidationError):
+        config.Settings()
+
+
+def test_extra_fields_forbidden():
+    """Test that extra fields are rejected."""
+    with pytest.raises(ValidationError):
+        config.Settings(**cast(Any, {"UNKNOWN_FIELD": "bad"}))
+
+
+def test_invalid_target_url_type():
+    """Test invalid TARGET_URL type."""
+    with pytest.raises(ValidationError):
+        config.Settings(TARGET_URL=cast(Any, "not-a-list"))
+
+
+def test_invalid_target_url_item_type():
+    """Test invalid TARGET_URL list item types."""
+    with pytest.raises(ValidationError):
+        config.Settings(TARGET_URL=cast(Any, [123, 456]))
+
+
+@pytest.mark.parametrize(
+    ("field", "value"),
+    [
+        ("NUM_REQUESTS", 1),
+        ("NUM_REQUESTS", 1_000_000),
+        ("CONNECT_TIMEOUT", 0.001),
+        ("CONNECT_TIMEOUT", 120),
+        ("READ_TIMEOUT", 0.001),
+        ("READ_TIMEOUT", 120),
+        ("REQUEST_DELAY", 0.001),
+        ("REQUEST_DELAY", 60),
+    ],
+)
+def test_valid_numeric_boundaries(field, value):
+    """Test valid numeric boundary values."""
+    s = config.Settings(**{field: value})
+
+    assert getattr(s, field) == value
+
+
+def test_settings_are_isolated():
+    """Test separate Settings instances do not share state."""
+    s1 = config.Settings(NUM_REQUESTS=10)
+    s2 = config.Settings(NUM_REQUESTS=20)
+
+    assert s1.NUM_REQUESTS == 10
+    assert s2.NUM_REQUESTS == 20
+
+
+def test_model_config_values():
+    """Test important model configuration values."""
+    cfg = config.Settings.model_config
+
+    assert cfg.get("extra") == "forbid"
+    assert cfg.get("validate_default") is True
+    assert cfg.get("env_file") == ".env"
+    assert cfg.get("env_file_encoding") == "utf-8"