Feature flags from json

feature-flag.py

import json


def read_json_file(file_path: str) -> dict:
    """
    Reads a JSON file and returns a dictionary containing its data.

    Args:
        file_path: The path to the JSON file to read.

    Returns:
        A dictionary containing the data from the JSON file.
    """
    with open(file_path, "r") as file:
        data = json.load(file)
    return data


feature_flags = read_json_file("data.json")


def get_feature_flag_state(feature_name: str, feature_flags: dict) -> bool:
    """
    Checks if a feature is enabled or not.

    Args:
        feature_name: The name of the feature to check.
        feature_flags: The dictionary of all feature flags.

    Returns:
        A boolean indicating if the feature is enabled or not.
    """
    return feature_flags["features"].get(feature_name, False)


def feature_1(number: int):
    print(f"Feature 1 with number {number}")


def feature_2(number: int):
    print(f"Feature 2 with number {number}")


def feature_flag(feature: str, feature_flags: dict = feature_flags):
    """
    A decorator that will swap the function with another one based on a feature flag.

    Args:
        feature: The name of the feature flag to check.
        feature_flags: The dictionary with all the feature flags.

    Returns:
        A function that will be called with the same arguments as the original function.
        If the feature flag is turned on, it will call the function associated with that
        feature instead of the original function.
    """
    choices = {"feature_1": feature_1, "feature_2": feature_2}

    def outer(func):
        def inner(*args, **kwargs):
            if not get_feature_flag_state(feature, feature_flags):
                func(*args, **kwargs)
                return
            choices[feature](*args, **kwargs)

        return inner

    return outer

@feature_flag("feature_1")
def main(number: int):
    print(f"Current feature with number {number}")


main(5)