Brandur Leach b9c7afd5fe
Reserve some critical field names when adding StripeObject accessors (#970)
When populating `StripeObject`s, we add accessors to them so that people
can access fields like `obj.currency`.

This was probably only meant to apply to API resources, but through
what might have been an accident of history, we've also traditionally
unmarshaled any hash that comes back from the API as a `StripeObject`,
including `metadata` fields. This allows some convenience because users
can access values like `obj.metadata.my_field`, but is also obviously a
minefield for potential problems.

In issue #969, what's essentially happening is that because there's a
metadata field named `class`, we've overwritten the object's normal
`class` method with our own custom one that accesses the metadata value.
Amazingly, the object can still marshal/unmarshal mostly properly, but
fails on this line as we try to access `obj.class` and that turns out to
be a metadata value instead of a class:

``` ruby
when StripeObject
  obj.class.construct_from(
    ...
```

Here I solve the problem by banning accessors added with the name
`class`. This has a slight risk of backward incompatibility in that
users that previously had metadata named "class" will now have to use
square bracket accessors instead like `obj.metadata[:class]`, but
honestly, I just can't see anything good in allowing "class" to be used
as an accessor.

An alternative solution might be to alias `class` in `StripeObject` and
then make sure we always use that in places like `initialize_from` and
`deep_copy`.

The best long term solution would be to stop add accessors to metadata
objects. This just seems like a bad idea given that there are still
myriads of Ruby built-ins that could potentially be overwritten. This is
definitely a considerably-sized breaking change though, so we'd have to
do it on a major.
2021-04-02 11:08:56 -07:00
..
2019-08-20 11:35:24 -07:00
2021-03-10 14:48:48 -05:00