[Feature request][test]: Allow overriding Block in `override_data`

[IppX]

Terraform Version

Terraform v1.13.4
on darwin_arm64

Use Cases

When trying to use override_data in a unit test, if an argument in the underlying data source is implemented with a Block, override_data does not override the argument.

This is silent and leads to a frustrating experience as a developer.

I'm posting this request following a discussion in Discuss (see references section).

Attempted Solutions

Blocks are not considered computed and thus are not overriden in tests.

A workaround is to define an empty block in the source data and then one can override the data block in tests.

Example:

# in root module
data "data_with_block" this {
    my_block {}
}

# and in test
run {
    override_data {
        target = data_with_block.this
        values = {
            my_block = {
                  key = "value"
            }
        }
    }
}

See References for a concrete example from Discuss forums.

Proposal

No response

References

• https://discuss.hashicorp.com/t/override-data-in-tests-not-able-to-override-block-attributes/76733

[jbardin]

Hi @IppX,

Thanks for filing the issue. Aside from the inability to assign the override data, it seems the DataDog data resource is technically implemented incorrectly and is slipping past any validation of the data resource schema. A block is a description of configuration syntax, and since the output here is entirely computed by the provider, it is not something which is written in the configuration, hence there is no correct type of block to represent it.

The plugin framework provides structural attributes which fulfill this need, and newer providers can make use of those to create more complex computed structures. In the meantime however this is likely going to be a concern for legacy providers, and we can look into finding a sensible solution for override_data to be applied against blocks.