v1.4.7/internal/terraform/testdata/plan-module-multi-var/main.tf - terraform - Git at Google

 resource "aws_instance" "parent" {
   count = 2
 }

 module "child" {
   source = "./child"
   things = "${join(",", aws_instance.parent.*.id)}"
 }
	resource "aws_instance" "parent" {
	count = 2
	}

	module "child" {
	source = "./child"
	things = "${join(",", aws_instance.parent.*.id)}"
	}