Cover empty sets

hashicorp · Sep 10, 2019 · 7e2ab78 · 7e2ab78
1 parent 4e17209
commit 7e2ab78
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Showing 3 changed files with 11 additions and 5 deletions.
diff --git a/terraform/eval_for_each.go b/terraform/eval_for_each.go
@@ -52,6 +52,10 @@ func evaluateResourceForEachExpressionKnown(expr hcl.Expression, ctx EvalContext
 		return nil, true, diags
 	case !forEachVal.IsKnown():
 		return map[string]cty.Value{}, false, diags
+	// If the map is empty ({}), return an empty map, because cty will return nil when representing {} AsValueMap
+	// This also covers an empty set (toset([]))
+	case forEachVal.LengthInt() == 0:
+		return map[string]cty.Value{}, true, diags
 	}
 
 	if !forEachVal.CanIterateElements() || forEachVal.Type().IsListType() || forEachVal.Type().IsTupleType() {
@@ -84,10 +88,5 @@ func evaluateResourceForEachExpressionKnown(expr hcl.Expression, ctx EvalContext
 		}
 	}
 
-	// If the map is empty ({}), return an empty map, because cty will return nil when representing {} AsValueMap
-	if forEachVal.LengthInt() == 0 {
-		return map[string]cty.Value{}, true, diags
-	}
-
 	return forEachVal.AsValueMap(), true, nil
 }
diff --git a/terraform/graph_builder_plan_test.go b/terraform/graph_builder_plan_test.go
@@ -338,6 +338,8 @@ var.foo
 const testPlanGraphBuilderForEachStr = `
 aws_instance.bar
   provider.aws
+aws_instance.bar2
+  provider.aws
 aws_instance.bat
   aws_instance.boo
   provider.aws
@@ -349,6 +351,7 @@ aws_instance.foo
   provider.aws
 meta.count-boundary (EachMode fixup)
   aws_instance.bar
+  aws_instance.bar2
   aws_instance.bat
   aws_instance.baz
   aws_instance.boo
@@ -357,6 +360,7 @@ meta.count-boundary (EachMode fixup)
 provider.aws
 provider.aws (close)
   aws_instance.bar
+  aws_instance.bar2
   aws_instance.bat
   aws_instance.baz
   aws_instance.boo

diff --git a/terraform/testdata/plan-for-each/main.tf b/terraform/testdata/plan-for-each/main.tf
@@ -10,6 +10,9 @@ resource "aws_instance" "foo" {
 
 # sets
 resource "aws_instance" "bar" {
+    for_each = toset([])
+}
+resource "aws_instance" "bar2" {
     for_each = toset(list("z", "y", "x"))
 }