From b3adcf06a1c41a332104d32f4766d093eb6cbc42 Mon Sep 17 00:00:00 2001
From: James Bardin <j.bardin@gmail.com>
Date: Thu, 3 Feb 2022 17:31:23 -0500
Subject: [PATCH] find meta references through locals

---
 .../globalref/analyzer_meta_references.go     | 20 +++++++++++++++++++
 .../analyzer_meta_references_test.go          |  7 +++++++
 .../testdata/assorted/assorted-root.tf        |  2 +-
 .../compute/contributing-resources-compute.tf |  4 +++-
 4 files changed, 31 insertions(+), 2 deletions(-)

diff --git a/internal/lang/globalref/analyzer_meta_references.go b/internal/lang/globalref/analyzer_meta_references.go
index b7c6db22e..4646b55e5 100644
--- a/internal/lang/globalref/analyzer_meta_references.go
+++ b/internal/lang/globalref/analyzer_meta_references.go
@@ -40,6 +40,8 @@ func (a *Analyzer) MetaReferences(ref Reference) []Reference {
 	switch targetAddr := ref.LocalRef.Subject.(type) {
 	case addrs.InputVariable:
 		return a.metaReferencesInputVariable(moduleAddr, targetAddr, remaining)
+	case addrs.LocalValue:
+		return a.metaReferencesLocalValue(moduleAddr, targetAddr, remaining)
 	case addrs.ModuleCallInstanceOutput:
 		return a.metaReferencesOutputValue(moduleAddr, targetAddr, remaining)
 	case addrs.ModuleCallInstance:
@@ -136,6 +138,23 @@ func (a *Analyzer) metaReferencesOutputValue(callerAddr addrs.ModuleInstance, ad
 	return absoluteRefs(calleeAddr, refs)
 }
 
+func (a *Analyzer) metaReferencesLocalValue(moduleAddr addrs.ModuleInstance, addr addrs.LocalValue, remain hcl.Traversal) []Reference {
+	modCfg := a.ModuleConfig(moduleAddr)
+	if modCfg == nil {
+		return nil
+	}
+
+	local := modCfg.Locals[addr.Name]
+	if local == nil {
+		return nil
+	}
+
+	// We don't check for errors here because we'll make a best effort to
+	// analyze whatever partial result HCL is able to extract.
+	refs, _ := lang.ReferencesInExpr(local.Expr)
+	return absoluteRefs(moduleAddr, refs)
+}
+
 func (a *Analyzer) metaReferencesModuleCall(callerAddr addrs.ModuleInstance, addr addrs.ModuleCallInstance, remain hcl.Traversal) []Reference {
 	calleeAddr := callerAddr.Child(addr.Call.Name, addr.Key)
 
@@ -181,6 +200,7 @@ func (a *Analyzer) metaReferencesResourceInstance(moduleAddr addrs.ModuleInstanc
 	if providerSchema == nil {
 		return nil
 	}
+
 	resourceTypeSchema, _ := providerSchema.SchemaForResourceAddr(addr.Resource)
 	if resourceTypeSchema == nil {
 		return nil
diff --git a/internal/lang/globalref/analyzer_meta_references_test.go b/internal/lang/globalref/analyzer_meta_references_test.go
index 340e8760f..c693890cf 100644
--- a/internal/lang/globalref/analyzer_meta_references_test.go
+++ b/internal/lang/globalref/analyzer_meta_references_test.go
@@ -19,6 +19,13 @@ func TestAnalyzerMetaReferences(t *testing.T) {
 			`local.a`,
 			nil,
 		},
+		{
+			``,
+			`local.single`,
+			[]string{
+				"::test_thing.single.id",
+			},
+		},
 		{
 			``,
 			`test_thing.single`,
diff --git a/internal/lang/globalref/testdata/assorted/assorted-root.tf b/internal/lang/globalref/testdata/assorted/assorted-root.tf
index d61297232..09f730eee 100644
--- a/internal/lang/globalref/testdata/assorted/assorted-root.tf
+++ b/internal/lang/globalref/testdata/assorted/assorted-root.tf
@@ -1,7 +1,7 @@
-
 locals {
   a = "hello world"
   b = 2
+  single = test_thing.single.id
 }
 
 resource "test_thing" "single" {
diff --git a/internal/lang/globalref/testdata/contributing-resources/compute/contributing-resources-compute.tf b/internal/lang/globalref/testdata/contributing-resources/compute/contributing-resources-compute.tf
index c83daffe8..a88ec466f 100644
--- a/internal/lang/globalref/testdata/contributing-resources/compute/contributing-resources-compute.tf
+++ b/internal/lang/globalref/testdata/contributing-resources/compute/contributing-resources-compute.tf
@@ -20,6 +20,8 @@ locals {
       }
     ]
   ])
+
+  controllers = test_thing.controller
 }
 
 resource "test_thing" "worker" {
@@ -39,7 +41,7 @@ resource "test_thing" "load_balancer" {
   string = var.network.vpc_id
 
   dynamic "list" {
-    for_each = test_thing.controller
+    for_each = local.controllers
     content {
       z = list.value.string
     }