Integer property with default 0 is incorrectly nullable

[dktapps]

Describe the bug
A property with a default value is not typically nullable, but if its default is 0, it's marked as nullable anyway.

Expected behavior
Integer properties with 0 as the default value shouldn't be nullable.

Schema

				"global-limit": {
					"type": "integer",
					"minimum": 0,
					"description": "Global soft memory limit (MB). When reached, low-memory triggers will fire to try and free memory.",
					"default": 1
				},

Version:
Which version of the library do you use?
dev-master as of about 1h ago.

Additional context
My bet is that there's some weak comparison == somewhere that's responsible for this bug.

[wol-soft]

Yeah, I've spotted the problem. It's caused by the string "0" evaluating to false. I'll patch the master branch with a test covering the case.

[wol-soft]

I've tagged a new bugfix version (0.21.1) which includes the fixes for the issues you opened. Thanks for the reports again!

I hope the library is useful for you, would be glad to hear how it's going 😃

[dktapps]

I've actually been searching for something like this for a long time, I had the same idea several years ago wrt. codegen but never found the time or motivation to do it.

I'm very happy with it so far, it's greatly improved validation of various configs used in PocketMine-MP.