feat: add logger module (#37)

src/fastapi_toolsets/cli/app.py

@@ -2,6 +2,7 @@
 
 import typer
 
+from ..logger import configure_logging
 from .config import get_custom_cli
 from .pyproject import load_pyproject
 
@@ -27,4 +28,5 @@ if _config.get("fixtures") and _config.get("db_context"):
 @cli.callback()
 def main(ctx: typer.Context) -> None:
     """FastAPI utilities CLI."""
+    configure_logging()
     ctx.ensure_object(dict)

src/fastapi_toolsets/fixtures/registry.py

@@ -1,15 +1,15 @@
 """Fixture system with dependency management and context support."""
 
-import logging
 from collections.abc import Callable, Sequence
 from dataclasses import dataclass, field
 from typing import Any, cast
 
 from sqlalchemy.orm import DeclarativeBase
 
+from ..logger import get_logger
 from .enum import Context
 
-logger = logging.getLogger(__name__)
+logger = get_logger()
 
 
 @dataclass

src/fastapi_toolsets/fixtures/utils.py

@@ -1,4 +1,3 @@
-import logging
 from collections.abc import Callable, Sequence
 from typing import Any, TypeVar
 
@@ -6,10 +5,11 @@ from sqlalchemy.ext.asyncio import AsyncSession
 from sqlalchemy.orm import DeclarativeBase
 
 from ..db import get_transaction
+from ..logger import get_logger
 from .enum import LoadStrategy
 from .registry import Context, FixtureRegistry
 
-logger = logging.getLogger(__name__)
+logger = get_logger()
 
 T = TypeVar("T", bound=DeclarativeBase)
 

src/fastapi_toolsets/logger.py

@@ -0,0 +1,81 @@
+"""Logging configuration for FastAPI applications and CLI tools."""
+
+import logging
+import sys
+from typing import Literal
+
+__all__ = ["LogLevel", "configure_logging", "get_logger"]
+
+DEFAULT_FORMAT = "%(asctime)s - %(name)s - %(levelname)s - %(message)s"
+UVICORN_LOGGERS = ("uvicorn", "uvicorn.access", "uvicorn.error")
+
+LogLevel = Literal["DEBUG", "INFO", "WARNING", "ERROR", "CRITICAL"]
+
+
+def configure_logging(
+    level: LogLevel | int = "INFO",
+    fmt: str = DEFAULT_FORMAT,
+    logger_name: str | None = None,
+) -> logging.Logger:
+    """Configure logging with a stdout handler and consistent format.
+
+    Sets up a :class:`~logging.StreamHandler` writing to stdout with the
+    given format and level.  Also configures the uvicorn loggers so that
+    FastAPI access logs use the same format.
+
+    Calling this function multiple times is safe -- existing handlers are
+    replaced rather than duplicated.
+
+    Args:
+        level: Log level (e.g. ``"DEBUG"``, ``"INFO"``, or ``logging.DEBUG``).
+        fmt: Log format string.  Defaults to
+            ``"%(asctime)s - %(name)s - %(levelname)s - %(message)s"``.
+        logger_name: Logger name to configure.  ``None`` (the default)
+            configures the root logger so all loggers inherit the settings.
+
+    Returns:
+        The configured Logger instance.
+    """
+    formatter = logging.Formatter(fmt)
+
+    handler = logging.StreamHandler(sys.stdout)
+    handler.setFormatter(formatter)
+
+    logger = logging.getLogger(logger_name)
+    logger.handlers.clear()
+    logger.addHandler(handler)
+    logger.setLevel(level)
+
+    for name in UVICORN_LOGGERS:
+        uv_logger = logging.getLogger(name)
+        uv_logger.handlers.clear()
+        uv_logger.addHandler(handler)
+        uv_logger.setLevel(level)
+
+    return logger
+
+
+_SENTINEL = object()
+
+
+def get_logger(name: str | None = _SENTINEL) -> logging.Logger:  # type: ignore[assignment]
+    """Return a logger with the given *name*.
+
+    A thin convenience wrapper around :func:`logging.getLogger` that keeps
+    logging imports consistent across the codebase.
+
+    When called without arguments, the caller's ``__name__`` is used
+    automatically, so ``get_logger()`` in a module is equivalent to
+    ``logging.getLogger(__name__)``.  Pass ``None`` explicitly to get the
+    root logger.
+
+    Args:
+        name: Logger name.  Defaults to the caller's ``__name__``.
+            Pass ``None`` to get the root logger.
+
+    Returns:
+        A Logger instance.
+    """
+    if name is _SENTINEL:
+        name = sys._getframe(1).f_globals.get("__name__")
+    return logging.getLogger(name)

tests/test_logger.py

@@ -0,0 +1,118 @@
+import logging
+import sys
+
+import pytest
+
+from fastapi_toolsets.logger import (
+    DEFAULT_FORMAT,
+    UVICORN_LOGGERS,
+    configure_logging,
+    get_logger,
+)
+
+
+@pytest.fixture(autouse=True)
+def _reset_loggers():
+    """Reset the root and uvicorn loggers after each test."""
+    yield
+    root = logging.getLogger()
+    root.handlers.clear()
+    root.setLevel(logging.WARNING)
+    for name in UVICORN_LOGGERS:
+        uv = logging.getLogger(name)
+        uv.handlers.clear()
+        uv.setLevel(logging.NOTSET)
+
+
+class TestConfigureLogging:
+    def test_sets_up_handler_and_format(self):
+        logger = configure_logging()
+
+        assert len(logger.handlers) == 1
+        handler = logger.handlers[0]
+        assert isinstance(handler, logging.StreamHandler)
+        assert handler.stream is sys.stdout
+        assert handler.formatter is not None
+        assert handler.formatter._fmt == DEFAULT_FORMAT
+
+    def test_default_level_is_info(self):
+        logger = configure_logging()
+
+        assert logger.level == logging.INFO
+
+    def test_custom_level_string(self):
+        logger = configure_logging(level="DEBUG")
+
+        assert logger.level == logging.DEBUG
+
+    def test_custom_level_int(self):
+        logger = configure_logging(level=logging.WARNING)
+
+        assert logger.level == logging.WARNING
+
+    def test_custom_format(self):
+        custom_fmt = "%(levelname)s: %(message)s"
+        logger = configure_logging(fmt=custom_fmt)
+
+        handler = logger.handlers[0]
+        assert handler.formatter is not None
+        assert handler.formatter._fmt == custom_fmt
+
+    def test_named_logger(self):
+        logger = configure_logging(logger_name="myapp")
+
+        assert logger.name == "myapp"
+        assert len(logger.handlers) == 1
+
+    def test_default_configures_root_logger(self):
+        logger = configure_logging()
+
+        assert logger is logging.getLogger()
+
+    def test_idempotent_no_duplicate_handlers(self):
+        configure_logging()
+        configure_logging()
+        logger = configure_logging()
+
+        assert len(logger.handlers) == 1
+
+    def test_configures_uvicorn_loggers(self):
+        configure_logging(level="DEBUG")
+
+        for name in UVICORN_LOGGERS:
+            uv_logger = logging.getLogger(name)
+            assert len(uv_logger.handlers) == 1
+            assert uv_logger.level == logging.DEBUG
+            handler = uv_logger.handlers[0]
+            assert handler.formatter is not None
+            assert handler.formatter._fmt == DEFAULT_FORMAT
+
+    def test_returns_configured_logger(self):
+        logger = configure_logging(logger_name="test.return")
+
+        assert isinstance(logger, logging.Logger)
+        assert logger.name == "test.return"
+
+
+class TestGetLogger:
+    def test_returns_named_logger(self):
+        logger = get_logger("myapp.services")
+
+        assert isinstance(logger, logging.Logger)
+        assert logger.name == "myapp.services"
+
+    def test_returns_root_logger_when_none(self):
+        logger = get_logger(None)
+
+        assert logger is logging.getLogger()
+
+    def test_defaults_to_caller_module_name(self):
+        logger = get_logger()
+
+        assert logger.name == __name__
+
+    def test_same_name_returns_same_logger(self):
+        a = get_logger("myapp")
+        b = get_logger("myapp")
+
+        assert a is b