fix: Lazy eval data source only if enabled (#76)

* eval data if enabled

* add a simple test for disabled path

* test with an unused api

Author: bharathkkb

examples/simple_example/main.tf

@@ -27,3 +27,14 @@ module "cli" {
   create_cmd_body  = "services enable youtube.googleapis.com --project ${var.project_id}"
   destroy_cmd_body = "services disable youtube.googleapis.com --project ${var.project_id}"
 }
+
+module "cli-disabled" {
+  source = "../.."
+
+  platform              = "linux"
+  additional_components = ["kubectl", "beta"]
+
+  enabled          = false
+  create_cmd_body  = "services enable datastore.googleapis.com --project ${var.project_id}"
+  destroy_cmd_body = "services disable datastore.googleapis.com --project ${var.project_id}"
+}

main.tf

@@ -22,7 +22,7 @@ locals {
   gcloud_bin_abs_path  = abspath(local.gcloud_bin_path)
   components           = join(",", var.additional_components)
 
-  download_override = data.external.env_override[0].result.download
+  download_override = var.enabled ? data.external.env_override[0].result.download : ""
   skip_download     = local.download_override == "always" ? false : (local.download_override == "never" ? true : var.skip_download)
 
   gcloud              = local.skip_download ? "gcloud" : "${local.gcloud_bin_path}/gcloud"

test/integration/simple_example/controls/gcloud.rb

@@ -19,5 +19,6 @@
     its(:exit_status) { should eq 0 }
     its(:stderr) { should eq "" }
     its(:stdout) { should match "youtube.googleapis.com" }
+    its(:stdout) { should_not match "datastore.googleapis.com" }
   end
 end