From f032ce6c1bf26653935fa1aabb058ff8f3e7afa1 Mon Sep 17 00:00:00 2001
From: Mitchell Hashimoto <mitchell.hashimoto@gmail.com>
Date: Tue, 17 Jun 2014 18:10:38 -0700
Subject: [PATCH] terraform: ResourceDiff tests

---
 terraform/diff.go      |  4 ++++
 terraform/diff_test.go | 26 ++++++++++++++++++++++++++
 2 files changed, 30 insertions(+)

diff --git a/terraform/diff.go b/terraform/diff.go
index bef052827..4baf2ebbc 100644
--- a/terraform/diff.go
+++ b/terraform/diff.go
@@ -98,6 +98,10 @@ type ResourceAttrDiff struct {
 // RequiresNew returns true if the diff requires the creation of a new
 // resource (implying the destruction of the old).
 func (d *ResourceDiff) RequiresNew() bool {
+	if d == nil {
+		return false
+	}
+
 	for _, rd := range d.Attributes {
 		if rd.RequiresNew {
 			return true
diff --git a/terraform/diff_test.go b/terraform/diff_test.go
index 7e7acda21..0e4d951d7 100644
--- a/terraform/diff_test.go
+++ b/terraform/diff_test.go
@@ -35,6 +35,32 @@ func TestDiff_String(t *testing.T) {
 	}
 }
 
+func TestResourceDiff_RequiresNew(t *testing.T) {
+	rd := &ResourceDiff{
+		Attributes: map[string]*ResourceAttrDiff{
+			"foo": &ResourceAttrDiff{},
+		},
+	}
+
+	if rd.RequiresNew() {
+		t.Fatal("should not require new")
+	}
+
+	rd.Attributes["foo"].RequiresNew = true
+
+	if !rd.RequiresNew() {
+		t.Fatal("should require new")
+	}
+}
+
+func TestResourceDiff_RequiresNew_nil(t *testing.T) {
+	var rd *ResourceDiff
+
+	if rd.RequiresNew() {
+		t.Fatal("should not require new")
+	}
+}
+
 const diffStrBasic = `
 CREATE: nodeA
   bar:     "foo" => "<computed>"