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Logger Port

logger_port

LoggerPort contract for abstract logging.

Defines the LoggerPort ABC that application code depends on,
decoupling logging from any specific logging library.

LoggerPort

Bases: OutboundPort

ABC for logging.

Explicit inheritance is required — debug, info,
warning, and error are @abstractmethod stubs
that subclasses must implement.

Responsibilities
  • Emit log messages at debug, info, warning, and error levels.
  • Accept format-style *args for string interpolation.
Non-Responsibilities
  • Persist log output or rotate log files.
  • Manage log levels, filters, or structured logging formats.
  • Schedule async I/O — this is a synchronous contract.

Implementations MAY accept wider types for *args (e.g.
*args: object) — the port contract only constrains callers,
not implementors.

Example 
log = MyLogger()
log.info("Order %s placed by user %s", "42", "alice")
log.error("Payment failed for order %s", "42")
Source code in src/forging_blocks/application/ports/outbound/logger_port.py 
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class LoggerPort(OutboundPort):
    """ABC for logging.

    Explicit inheritance is required — ``debug``, ``info``,
    ``warning``, and ``error`` are ``@abstractmethod`` stubs
    that subclasses must implement.

    Responsibilities:
        - Emit log messages at debug, info, warning, and error levels.
        - Accept format-style ``*args`` for string interpolation.

    Non-Responsibilities:
        - Persist log output or rotate log files.
        - Manage log levels, filters, or structured logging formats.
        - Schedule async I/O — this is a synchronous contract.

    Implementations MAY accept wider types for ``*args`` (e.g.
    ``*args: object``) — the port contract only constrains callers,
    not implementors.

    Example:
        ```python
        log = MyLogger()
        log.info("Order %s placed by user %s", "42", "alice")
        log.error("Payment failed for order %s", "42")
        ```
    """

    @abstractmethod
    def debug(self, msg: str, *args: str) -> None:
        """Log a debug message."""

    @abstractmethod
    def info(self, msg: str, *args: str) -> None:
        """Log an info message."""

    @abstractmethod
    def warning(self, msg: str, *args: str) -> None:
        """Log a warning message."""

    @abstractmethod
    def error(self, msg: str, *args: str) -> None:
        """Log an error message."""

debug(msg: str, *args: str) -> None abstractmethod

Log a debug message.

Source code in src/forging_blocks/application/ports/outbound/logger_port.py 
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@abstractmethod
def debug(self, msg: str, *args: str) -> None:
    """Log a debug message."""

info(msg: str, *args: str) -> None abstractmethod

Log an info message.

Source code in src/forging_blocks/application/ports/outbound/logger_port.py 
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@abstractmethod
def info(self, msg: str, *args: str) -> None:
    """Log an info message."""

warning(msg: str, *args: str) -> None abstractmethod

Log a warning message.

Source code in src/forging_blocks/application/ports/outbound/logger_port.py 
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@abstractmethod
def warning(self, msg: str, *args: str) -> None:
    """Log a warning message."""

error(msg: str, *args: str) -> None abstractmethod

Log an error message.

Source code in src/forging_blocks/application/ports/outbound/logger_port.py 
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@abstractmethod
def error(self, msg: str, *args: str) -> None:
    """Log an error message."""