JSON Response to lib Commands

[GItThatSparrow]

AS A User

I NEED TO determine the result of a call to the arduino-cli based on the response
AND the command specifies the --format=json parameter

SO THAT I can distinguish the difference in between a successful operation and a failed operation

---

Example

I issue a command like

>> arduino-cli lib install AudioZero@1.0.0 --format=json

But the response is empty, like:

>> arduino-cli lib install AudioZero@1.0.0 --format=json

>>

Equivalent example download

Same result when I issue a command like

>> arduino-cli lib download AudioZero --format=json   # or...
>> arduino-cli lib download AudioZero@1.0.0 --format=json

But the response is empty, like:

>> arduino-cli lib download AudioZero --format=json # or....

>>
>> arduino-cli lib download AudioZero@1.0.0 --format=json

>>

Equivalent example list

Same result when I issue a command like

>> arduino-cli lib list --format=json

But the response is empty, like:

>> arduino-cli lib list --format=json

>>

Equivalent example uninstall

Same result when I issue a command like

>> arduino-cli lib uninstall AudioZero@1.0.0 --format=json

But the response is empty, like:

>> arduino-cli lib uninstall AudioZero@1.0.0 --format=json

>>

Equivalent example update-index

Same result when I issue a command like

>> arduino-cli lib update-index --format=json

But the response is empty, like:

>> arduino-cli lib update-index --format=json

>>

Equivalent example upgrade

Same result when I issue a command like

>> arduino-cli lib upgrade --format=json

But the response is empty, like:

>> arduino-cli lib upgrade --format=json

>>

[philippejadin]

This is really important. I'm working on a python wrapper to have a thin compile server installable on clients (ala codebender, but running locally), and having some json return all the time is mandatory. Even if the json contains just error = true / error = false
See for instance this article : https://nordicapis.com/best-practices-api-error-handling/

In the meantime, I will check if the error codes returned are consistent (I hope they are :-) )

[mastrolinux]

@philippejadin you can probably now use the new GRPC interface. This bug is still confirmed and I am not use if best to return an empty json or something like {'success': 'true', 'message': 'some message here or empty string'}

[masci]

I think when invoking the CLI process the source of truth should always be the process exit code.

If the exit code is 0 operation was successful, otherwise you should make no assumptions about what's in the standard error/output: instead, you would look at the meaning of the exit code. Think about the CLI exiting because of a panic when likely the program wasn't able to properly print any output message, let alone a JSON structured message.

Different topic is whether printing an empty JSON object {} or nothing at all when the command succeeds but the result is empty. I personally like the docker approach, where nothing is printed if the response was empty (try doing docker ps --format='{{json .}}' vs docker ps when no containers are running).

[mastrolinux]

ok to have completely no output, it respects the UNIX phylosophy. I believe now the main issue is some commands returns code different from 0 even if the command run successfully (i.e. running twice lib install with the same libs)

[masci]

The expected behavior is:

• exit code of the CLI determines the status of the operation requested (success/fail)
• JSON output is only considered valid when the exit code is 0

I'm going to close this as what we have in master works as described.