On 04/06/18 20:10, Eric Blake wrote:
On 04/06/2018 12:28 PM, Laszlo Ersek wrote:
I've created an RFC-level "qapi/firmware.json" schema file, based on this discussion. It "builds", and the generated documentation looks acceptable, superficially speaking.
Before I post "qapi/firmware.json" for getting comments, I'd like to write JSON text that (a) describes firmware that I use, and (b) conforms to the schema. IOW, I'd like to validate whether the schema is good enough for describing at least such firmware that I know.
Is there a tool that generates example JSON objects from a given schema?
I know the QMP shell (scripts/qmp/qmp-shell) lets you enter commands with a lot less typing than full JSON, and has a mode where it will then echo the full JSON command it constructed from what you typed. To be able to quickly validate examples, it may be sufficient to temporarily add a new QMP command 'check-firmware':
{ 'command': 'check-firmware', 'boxed': true, 'data': 'Firmware' }
assuming 'Firmware' is your top-level 'struct' in the QAPI file, then implement a trivial:
qmp_check_firmware(Firmware *obj, Error **errp) { return 0; }
so that you can then run QMP shell, and type:
check-firmware arg1=foo arg2=bar ...
which will then generate the corresponding JSON, then either successfully do nothing (what you typed validated, AND you have the JSON output printed), or print an error (what you typed failed QAPI validation, perhaps because it had an unrecognized key, was missing a required key, used a wrong type, etc).
I vaguely recall there used to be one. Otherwise, writing the examples manually looks arduous (and I wouldn't know how to verify them against the schema).
Similarly, if you generate a command the produces a 'Firmware' as the return value, then you can populate the generated C struct (since you did manage to run the QAPI generator over your new file, you should be able to look at the C struct it generated), then output that over QMP to show the counterpart JSON that matches the struct as populated.
The top level structure is complex / nested, but that doesn't appear to be an issue. According to the script, # key=value pairs also support Python or JSON object literal subset notations, # without spaces. Dictionaries/objects {} are supported as are arrays []. # # example-command arg-name1={'key':'value','obj'={'prop':"value"}} # # Both JSON and Python formatting should work, including both styles of # string literal quotes. Both paradigms of literal values should work, # including null/true/false for JSON and None/True/False for Python. This looks awesome, because it should let me provide messy nested input (which I'll obviously compose in my $EDITOR and then paste it), and then the QMP shell will both validate and pretty print that. I'm going to try this. Thank you, Eric! Laszlo