Proposal: Allow removing key from `Private` data

[gdavison]

Module version

github.com/hashicorp/terraform-plugin-framework v1.5.0

Use-cases

Resource Private data may sometimes no longer be needed. There is currently no way to remove it.

Attempted Solutions

Setting a key to nil or "" causes an error, such as

The value being supplied for key "aws_lb_listener.importing" is invalid.
Please verify that the value is valid JSON.

Proposal

Add a corresponding function RemoveKey to *privatestate.ProviderData.

[bflad]

Hey @gdavison 👋 Thank you for raising this and we should certainly support this in some manner.

As a workaround for now, does SetKey(ctx, "key", []byte("null")) work for your use case? That should at least insert a literal JSON null as the value and appears to work in my quick SetKey() unit test trial -- leaving the key with a literal null value. Not exactly the most ideal, but should operate fairly similar from your end, I would think, in that reading it would require a pointer type that would unmarshal to nil.

In terms of actual key removal, I think we could support either a new RemoveKey(key string) method and/or update the existing SetKey() so it can support nil to remove the key. The latter might actually be preferable because it is likely that other developers may try exactly what you did and expect it to work. Semantically it feels like it would be performing the same change as what a RemoveKey() method would do under the hood anyways.

[gdavison]

Yes, I'm using the "null" workaround. I'm using the values true or null, so I check the content for equality instead of simple presence.

SetKey supporting nil would work

[github-actions]

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