Support return value when using CliRunner

[jayqi]

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Example Code

import typer
from typer.testing import CliRunner

app = typer.Typer()

@app.command()
def main():
    print("hello from stdout")
    return "hello from return_value"


runner = CliRunner()
result = runner.invoke(app)

result.exit_code
#> 0

result.stdout
#> 'hello from stdout\n'

result.return_value

result.return_value is None
#> True

^{Created at 2023-02-22 17:13:45 EST by reprexlite v1.0.0}

Description

Click v8.0.0 introduced the ability to capture the return value of a Click command when using Click's CliRunner to the return_value attribute of the Result object that CliRunner.invoke returns.

When using Typer's CliRunner, the return value seems to get lost and is not captured.

References:

• PR in Click that implemented this
• Click Result API Reference

Operating System

macOS

Operating System Details

No response

Typer Version

Typer 0.7.0

Python Version

Python 3.9.16

Additional Context

Click 8.1.3

[GiorgioSgl]

What about this?

This would be very helpful!

I'm in version 0.9.0 but still any update about this.

@jayqi Have you find any shortcut to solve the issue?

[GiorgioSgl]

Just found how to fix this just run the invoke method with standalone_mode=False

def test_app():
    result = runner.invoke(
        app, ["command"], standalone_mode=False
    )

    assert result.exit_code == 0
    print(result.return_value) # print the result and not get None

Idea by this