`paths` creates paths if they do not exist

[tobyink]

Migrated from rt.cpan.org #133925 (status was 'open')

Requestors:

• PCRONIN@cpan.org

From pcronin@cpan.org on 2020-12-20 12:14:37
:

Hi Kit,

Thanks very much for keeping this module going! I'm not sure if this is intended behavior or not, but it's not desirable for my use case, so I'll just mention it here. When using the paths method to get canonical paths for a JSONPath expression in an object, it creates those paths if they don't exist. The docs only mention that kind of behavior for the value and set methods, so I was surprised to see it for paths as well.

Here's a simple example:

$ perl -MJSON::Path -MDDP -e '$x={};@y=JSON::Path->new("$.a")->paths($x);p $x;p @y';
\ {
a undef
}
[
[0] undef
]

I'd have expected $x to remain an empty hashref because the JSONPath expression doesn't exist in it. I would also not expect an undef to be included in the found paths (I'd have expected an empty arrayref in this case.)

Am I thinking of this method in a way that wasn't intended?

If you think this is a bug, I can put together a PR to fix it.

[tobyink]

From popefelix@gmail.com on 2020-12-20 14:28:52
:

Yeah, this is a bug. If you wanted to do up a pr, I'd sure appreciate it

On Sun, Dec 20, 2020, 06:14 Patrick Cronin via RT bug-JSON-Path@rt.cpan.org
wrote:

Sun Dec 20 07:14:37 2020: Request 133925 was acted upon.
Transaction: Ticket created by PCRONIN
Queue: JSON-Path
Subject: paths creates paths if they do not exist
Broken in: 0.420
Severity: Normal
Owner: Nobody
Requestors: PCRONIN@cpan.org
Status: new
Ticket <URL: https://rt.cpan.org/Ticket/Display.html?id=133925 >

Hi Kit,

Thanks very much for keeping this module going! I'm not sure if this is
intended behavior or not, but it's not desirable for my use case, so I'll
just mention it here. When using the paths method to get canonical paths
for a JSONPath expression in an object, it creates those paths if they
don't exist. The docs only mention that kind of behavior for the value
and set methods, so I was surprised to see it for paths as well.

Here's a simple example:

$ perl -MJSON::Path -MDDP -e
'$x={};@y=JSON::Path->new("$.a")->paths($x);p $x;p @y';
\ {
a undef
}
[
[0] undef
]

I'd have expected $x to remain an empty hashref because the JSONPath
expression doesn't exist in it. I would also not expect an undef to be
included in the found paths (I'd have expected an empty arrayref in this
case.)

Am I thinking of this method in a way that wasn't intended?

If you think this is a bug, I can put together a PR to fix it.