FLASK_APP is unavailable when FlaskGroup is not used

[TitaniumHocker]

When cli group created with flask.cli.AppGroup and returned to cli instead of default flask.cli.FlaskGroup flask.cli.ScriptInfo failing to locate application with FLASK_APP environment variable with this error message:

Error: Could not locate a Flask application. Use the 'flask --app' option, 'FLASK_APP' environment variable, or a 'wsgi.py' or 'app.py' file in the current directory.

Here is a simple example of executable file main.py:

#!/usr/bin/env python
from os import environ

import click
from flask import Flask
from flask.cli import AppGroup

cli = AppGroup("main")


@cli.command()
def test():
    click.echo("Test command")


def create_app() -> Flask:
    app = Flask(__name__)
    app.cli.add_command(cli)
    return app


if __name__ == "__main__":
    environ.setdefault("FLASK_APP", "main:create_app")
    cli()

If run this file with flask<2.2.0:

$ ./main.py test
Test command

And with flask>=2.2.0:

$ ./main.py test
Usage: main.py test [OPTIONS]
Try 'main.py test --help' for help.

Error: Could not locate a Flask application. Use the 'flask --app' option, 'FLASK_APP' environment variable, or a 'wsgi.py' or 'app.py' file in the current directory.

I don't want to expand flask commands, so I don't use FlaskGroup, and use main.py script instead. This worked fine before 2.2.0.

I think this error is caused by this commit. Before 2.2.0 ScriptInfo locates app_import_path automatically from environment variable FLASK_APP, after 2.2.0 it expects that this value will be provided by --app of option FlaskGroup that can get it from FLASK_APP environment variable.

Environment:

• Python version: 3.11
• Flask version: >=2.2.0

[davidism]

You still need to run commands with the flask command, that's why you register them with app.cli.add_command.

$ flask main test

If you really want to use only your group and not the flask command, then you need to create the ScriptInfo object like FlaskGroup would have done for you.

if __name__ == "__main__":
    info = ScriptInfo(create_app=create_app)
    cli(obj=info)