Variable Validation should use lazy evaluation

[matteomazza91]

Terraform Version

0.12.24

Terraform Configuration Files

variable "my_variable_name" {
  type = object({
    a = string
    b = string
  })
  validation {
    condition     = var.my_variable_name == null || (var.my_variable_name.a != null && var.my_variable_name.b != null)
    error_message = "Something."
  }
}

Debug Output

Error: Attempt to get attribute from null value

  on [...]/variables.tf line 96, in variable "my_variable_name":
  96:     condition     = var.my_variable_name == null || (var.my_variable_name.a != null && var.my_variable_name.b != null)
    |----------------
    | var.my_variable_name is null

This value is null, so it does not have any attributes.

  on [...]/variables.tf line 96, in variable "my_variable_name":
  96:     condition     = var.my_variable_name == null || (var.my_variable_name.a != null && var.my_variable_name.b != null)
    |----------------
    | var.my_variable_name is null

This value is null, so it does not have any attributes.

Expected Behavior

if var.my_variable_name is null, the condition for variable-validation should evaluate to true

Actual Behavior

error returned because the right part of the validation expression is evaluated. It fails evaluating both var.my_variable_name.a and var.my_variable_name.b because var.my_variable_name is null

[jbardin]

Hello @matteomazza91,

Thanks for filing the issue. This isn't specific to variable validation, conditional operators not short-circuiting evaluation is a known issue we're tracking in #24128.

Closing as a duplicate.

[ghost]

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