New TestCheck helper TestCheckResourceAttrPairWith

[ewbankkit]

terraform-plugin-testing version

% go list -m github.com/hashicorp/terraform-plugin-testing/...
github.com/hashicorp/terraform-plugin-testing v1.5.1

Use cases

It would be handy to have a new TestCheck helper function that combines TestCheckResourceAttrWith and TestCheckResourceAttrPair, say TestCheckResourceAttrPairWith:

type CheckResourceAttrPairWithFunc func(valueFirst, valueSecond string) error

func TestCheckResourceAttrPairWith(nameFirst, keyFirst, nameSecond, keySecond string, checkValuesFunc CheckResourceAttrPairWithFunc) TestCheckFunc {
...
}

The canonical use case for the Terraform AWS Provider is to test logical equivalence (rather than byte-for-byte equivalence) of a data source's IAM policy document and a resource's IAM policy document.

[bendbennett]

The proposed ValueComparer interface in #295 could be something that provides way to achieve the equivalent of TestCheckResourceAttrPairWith as a "custom" comparer could be supplied to a CompareValuePairs constructor. For example:

func CompareValuePairs(resourceAddressOne string, attributePathOne tfjsonpath.Path, resourceAddressTwo string, attributePathTwo tfjsonpath.Path, comparer compare.ValueComparer) StateCheck {
	return &compareValuePairs{
		resourceAddressOne: resourceAddressOne,
		attributePathOne:   attributePathOne,
		resourceAddressTwo: resourceAddressTwo,
		attributePathTwo:   attributePathTwo,
		comparer:           comparer,
	}
}