From 02167dcfe4666ab010678c8579185df6c320e312 Mon Sep 17 00:00:00 2001
From: James Bardin <j.bardin@gmail.com>
Date: Mon, 15 Jun 2020 20:45:23 -0400
Subject: [PATCH 1/3] test whole module reference from module var

this reference isn't being connected properly
---
 terraform/context_plan_test.go | 45 ++++++++++++++++++++++++++++++++++
 1 file changed, 45 insertions(+)

diff --git a/terraform/context_plan_test.go b/terraform/context_plan_test.go
index 2c2282d93..9dfddceea 100644
--- a/terraform/context_plan_test.go
+++ b/terraform/context_plan_test.go
@@ -5947,3 +5947,48 @@ resource "aws_instance" "foo" {
 		t.Errorf("missing %s change for %s", action, res)
 	}
 }
+
+func TestContext2Plan_moduleRefIndex(t *testing.T) {
+	m := testModuleInline(t, map[string]string{
+		"main.tf": `
+module "mod" {
+  for_each = {
+    a = "thing"
+  }
+  in = null
+  source = "./mod"
+}
+
+module "single" {
+  source = "./mod"
+  in = module.mod["a"]
+}
+`,
+		"mod/main.tf": `
+variable "in" {
+}
+
+output "out" {
+  value = "foo"
+}
+
+resource "aws_instance" "foo" {
+}
+`,
+	})
+
+	p := testProvider("aws")
+	p.DiffFn = testDiffFn
+
+	ctx := testContext2(t, &ContextOpts{
+		Config: m,
+		Providers: map[addrs.Provider]providers.Factory{
+			addrs.NewDefaultProvider("aws"): testProviderFuncFixed(p),
+		},
+	})
+
+	_, diags := ctx.Plan()
+	if diags.HasErrors() {
+		t.Fatal(diags.ErrWithWarnings())
+	}
+}

From d6ca469124356061a087d33e5f8a4fb5f54b8434 Mon Sep 17 00:00:00 2001
From: James Bardin <j.bardin@gmail.com>
Date: Mon, 15 Jun 2020 20:46:03 -0400
Subject: [PATCH 2/3] module variables can't be referenced as a module

---
 terraform/node_module_variable.go | 6 +-----
 1 file changed, 1 insertion(+), 5 deletions(-)

diff --git a/terraform/node_module_variable.go b/terraform/node_module_variable.go
index c1ec01e27..e0d007f59 100644
--- a/terraform/node_module_variable.go
+++ b/terraform/node_module_variable.go
@@ -95,11 +95,7 @@ func (n *nodeExpandModuleVariable) ReferenceOutside() (selfPath, referencePath a
 
 // GraphNodeReferenceable
 func (n *nodeExpandModuleVariable) ReferenceableAddrs() []addrs.Referenceable {
-	// FIXME: References for module variables probably need to be thought out a bit more
-	// Otherwise, we can reference the output via the address itself, or the
-	// module call
-	_, call := n.Module.Call()
-	return []addrs.Referenceable{n.Addr, call}
+	return []addrs.Referenceable{n.Addr}
 }
 
 // RemovableIfNotTargeted

From 7154c61f0b3e09a879c20d445235233b2741fd90 Mon Sep 17 00:00:00 2001
From: James Bardin <j.bardin@gmail.com>
Date: Mon, 15 Jun 2020 20:46:53 -0400
Subject: [PATCH 3/3] reduce module instances refs to the module call

There aren't going to be any nodes specifically for module call
instances during plan, so we have to switch the reference subject to the
general module call.
---
 terraform/transform_reference.go | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/terraform/transform_reference.go b/terraform/transform_reference.go
index 94659e380..6a0ee98fa 100644
--- a/terraform/transform_reference.go
+++ b/terraform/transform_reference.go
@@ -303,6 +303,8 @@ func (m ReferenceMap) References(v dag.Vertex) []dag.Vertex {
 				subject = ri.ContainingResource()
 			case addrs.AbsModuleCallOutput:
 				subject = ri.ModuleCallOutput()
+			case addrs.ModuleCallInstance:
+				subject = ri.Call
 			default:
 				log.Printf("[WARN] ReferenceTransformer: reference not found: %q", subject)
 				continue