[bug] Custom command format example wrong in documentation

[akielbas]

Describe the bug

Following the example posted here: https://docs.conan.io/2/reference/extensions/custom_commands.html#decorators

Implementation of def output_json seems to be missing call to cli_out_write (does a return instead).

Suggested fix:

import json

from conan.api.conan_api import ConanAPI
from conan.api.output import ConanOutput, cli_out_write
from conan.cli.command import conan_command

def output_json(msg):
    myjson = json.dumps({"greet": msg})
    cli_out_write(myjson)


@conan_command(group="Custom commands", formatters={"json": output_json})
def hello(conan_api: ConanAPI, parser, *args):
    """
    Simple command to print "Hello World!" line
    """
    msg = "Hello World!"
    ConanOutput().info(msg)
    return msg

How to reproduce it

Implement a custom command from example extensions/commands/greet/cmd_hello.py with following contents:

import json

from conan.api.conan_api import ConanAPI
from conan.api.output import ConanOutput
from conan.cli.command import conan_command

def output_json(msg):
    return json.dumps({"greet": msg})


@conan_command(group="Custom commands", formatters={"json": output_json})
def hello(conan_api: ConanAPI, parser, *args):
    """
    Simple command to print "Hello World!" line
    """
    msg = "Hello World!"
    ConanOutput().info(msg)
    return msg

Then run conan greet:hello --format json. There is no JSON output.

[AbrilRBS]

Hi @akielbas thanks a lot for taking the time to report this.

You're right that this should be a call as you suggested. If you want to open a PR for release/2.19 branch, we'd be happy to merge the PR, otherwise we can also add it, no worries :)

[akielbas]

I targeted develop2, I can retarget for release/2.19 if you prefer?

[memsharded]

Closed by #4198 many thanks!