fix default value set for bool type

[AllyW]

bool is subclass of int, while default True or False should not be converted into int 1 or 0.
Otherwise, type check would fail for aaz cmds (https://github.com/Azure/azure-cli/blob/58ac6ab07fa850e1a6458dec87af91cd6725069e/src/azure-cli-core/azure/cli/core/aaz/_field_type.py#L47)

[AllyW]

in this pr: Azure/azure-cli#26819
aaz cmd:

before:

after:

[jiasli]

I don't think we can simply pass here, as this will make it impossible to distinguish whether the received True is user specified or the default value.

[kairu-ms]

I think it's useless, because it only added is_default property for str and int, not cover the other types, such as bool, float, timestamp etc.

[kairu-ms]

BTW, I also found the following lines has a bug when the arg_default is 0 int value

knack/knack/commands.py

Lines 129 to 131 in e496c95

	# update the default
	if arg_default:
	arg.type.settings['default'] = arg_default

[jiasli]

Could you please elaborate what the bug is?

[jiasli]

After reviewing the code, I feel this if arg_default: statement is deliberately added in order to ignore False/0 as default.

For example, for arguments --disable-integrity-monitoring and --disable-integrity-monitoring-autoupgrade of az vm create, their default values are False/0, so they are deliberately omitted from the help message:

> az vm create -h
...
    --disable-integrity-monitoring                      : Disable the default behavior of installing
                                                          guest attestation extension and enabling
                                                          System Assigned Identity for Trusted
                                                          Launch enabled VMs and VMSS.
    --disable-integrity-monitoring-autoupgrade          : Disable auto upgrade of guest attestation
                                                          extension for Trusted Launch enabled VMs
                                                          and VMSS.

[AllyW]

corresponding swagger line：
https://github.com/Azure/azure-rest-api-specs/blob/493aa7224fd65fe1e5b4cff59bcae5c6cdf4525e/specification/monitor/resource-manager/Microsoft.Insights/preview/2023-05-01-preview/tenantActionGroups_API.json#L570

[jiasli]

Also see https://stackoverflow.com/questions/37888620/comparing-boolean-and-int-using-isinstance

[jiasli]

Code comment should usually not focus on adjustment, but the status quo.

We can get the short link for a Stackoverflow post via the "share" button:

Suggested change

	# adjust here is because:
	# 1) bool is subclass of int so isinstance(True, int) cannot distinguish between int and bool
	# 2) bool is not extendable according to
	# https://stackoverflow.com/questions/2172189/why-i-cant-extend-bool-in-python,
	# so bool's is_default is ignored for now
	# bool's is_default is ignored for now, because
	# 1. bool is a subclass of int, so isinstance(True, int) cannot distinguish between int and bool
	# 2. bool is not extendable according to https://stackoverflow.com/a/2172204/2199657

[jiasli]

As a side note, Azure/azure-cli#16081 took a different approach. It sets the default value of role to None and defaulting it to Contributor manually in custom.py's code.

[jiasli]

The C source code of bool also mentions:

https://github.com/python/cpython/blob/832c37d42a395d4ea45994daffa5e41bd74ac1bb/Objects/boolobject.c#L118

The class bool is a subclass of the class int, and cannot be subclassed.

An alternative is to consider developing our own Bool and implementing special methods such as __bool__, __str__, so that it acts like a real bool, and also bears additional attribute is_default.