Confusing error message: "Inconsistent conditional result types. The given expressions are object and object, respectively."

[orgads]

Terraform Version

Terraform v1.1.6
on linux_amd64

output "test" {
  value = true ? { foo = { bar = 42 } } : { bar = 44 }
}

Debug Output

https://gist.github.com/orgads/3b408edbceccfe3e259daaa880ffe6d0

Expected Behavior

I expect it to work, as both types are objects.

In my case, I needed it as an input to merge.

Actual Behavior

The true and false result expressions must have consistent types. The given expressions are object and object, respectively.

Steps to Reproduce

1. terraform init
2. terraform apply

References

• Inconsistent conditional result types : The given expressions are object and object, respectively. #23364
• The true and false result expressions must have consistent types. The given expressions are object and object, respectively. #27877

[kmoe]

Thanks for opening this issue. The two expressions in this conditional are both object types, but two objects with attribute types which are collections or structural types (e.g. { bar = 42 }) must have the same attribute types in order for Terraform to consider them convertible.

For example, the following two objects are convertible:
{ foo = { bar = 42 } }
{ foo = { bar = 44 } }

but the following two are not:
{ foo = { bar = 42 } }
{ foo = 41 }

However, the error message "The given expressions are object and object, respectively" is clearly not helpful here. This ticket will be left open until we have improved this error message. Thanks again for bringing this to our attention!

[orgads]

Thank you!

[github-actions]

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