local_run.py

from __future__ import annotations

from dotenv import load_dotenv

load_dotenv()

from flask import Flask
from flask import request
from slack_bolt import BoltRequest
from slack_bolt.app import App
from slack_bolt.oauth import OAuthFlow

from lambda_handler import bolt_app


def run(app: App):
    @app.use
    def print_request(request: BoltRequest, next, logger):
        logger.info(f'Request body: {request.body}')
        next()

    from flask import Request, Response, make_response
    from slack_bolt.adapter.flask.handler import to_flask_response, to_bolt_request

    class LocalFlaskAppHandler:
        def __init__(self, app: App):  # type: ignore
            self.app = app

        def handle(self, req: Request) -> Response:
            if req.method == 'GET':
                if self.app.oauth_flow is not None:
                    oauth_flow: OAuthFlow = self.app.oauth_flow
                    if 'code' in req.args or 'error' in req.args:
                        bolt_resp = oauth_flow.handle_callback(to_bolt_request(req))
                        return to_flask_response(bolt_resp)
                    else:
                        bolt_resp = oauth_flow.handle_installation(to_bolt_request(req))
                        return to_flask_response(bolt_resp)
            elif req.method == 'POST':
                bolt_resp = self.app.dispatch(to_bolt_request(req))
                return to_flask_response(bolt_resp)

            return make_response('Not Found', 404)

    flask_app = Flask(__name__)
    handler = LocalFlaskAppHandler(app)

    # Run server locally: http://localhost:5000
    @flask_app.route('/', methods=['GET', 'POST'])
    def slack_events():
        return handler.handle(request)

    flask_app.run()


run(bolt_app)