This pull request resolves #137 by providing the access to the DefaultCallbackOptions handlers in callback options. As mentioned in the issue #137, this arg is greatly useful for developers that would like to reuse redirect_uri_page_renderer and so on in callback_options handlers.

def success(args: SuccessArgs) -> BoltResponse:
    # Do anything here ...

    # Call the default handler to return HTTP response
    return args.default.success(args)

def failure(args: FailureArgs) -> BoltResponse:
    # Do anything here ...

    # Call the default handler to return HTTP response
    return args.default.failure(args)

app = App(
    oauth_settings=OAuthSettings(
        callback_options=CallbackOptions(success=success, failure=failure),
    ),
)

Category (place an x in each of the [ ])

• slack_bolt.App and/or its core components
• slack_bolt.async_app.AsyncApp and/or its core components
• Adapters in slack_bolt.adapter
• Document pages under /docs
• Others

Requirements (place an x in each [ ])

Please read the Contributing guidelines and Code of Conduct before creating this issue or pull request. By submitting, you are agreeing to those rules.

• I've read and understood the Contributing Guidelines and have done my best effort to follow them.
• I've read and agree to the Code of Conduct.
• I've run ./scripts/install_all_and_run_tests.sh after making the changes.