From 3f49227b729df73cdff7a13e5654f1d24c8373fe Mon Sep 17 00:00:00 2001
From: James Bardin <j.bardin@gmail.com>
Date: Sat, 8 Apr 2017 15:15:18 -0400
Subject: [PATCH] add state an context tests

Make sure duplicate depends_on entries are pruned from existing states
on read.

Make sure new state built from configs with multiple references to the
same resource only add it once to the Dependencies.
---
 terraform/context_apply_test.go               | 29 ++++++++++
 terraform/state_test.go                       | 56 +++++++++++++++++++
 .../test-fixtures/apply-multi-ref/main.tf     |  8 +++
 3 files changed, 93 insertions(+)
 create mode 100644 terraform/test-fixtures/apply-multi-ref/main.tf

diff --git a/terraform/context_apply_test.go b/terraform/context_apply_test.go
index afe2f85a71..7d5bbf025f 100644
--- a/terraform/context_apply_test.go
+++ b/terraform/context_apply_test.go
@@ -8100,3 +8100,32 @@ func TestContext2Apply_terraformEnv(t *testing.T) {
 		t.Fatalf("bad: \n%s", actual)
 	}
 }
+
+// verify that multiple config references only create a single depends_on entry
+func TestContext2Apply_multiRef(t *testing.T) {
+	m := testModule(t, "apply-multi-ref")
+	p := testProvider("aws")
+	p.ApplyFn = testApplyFn
+	p.DiffFn = testDiffFn
+
+	ctx := testContext2(t, &ContextOpts{
+		Module: m,
+		Providers: map[string]ResourceProviderFactory{
+			"aws": testProviderFuncFixed(p),
+		},
+	})
+
+	if _, err := ctx.Plan(); err != nil {
+		t.Fatalf("err: %s", err)
+	}
+
+	state, err := ctx.Apply()
+	if err != nil {
+		t.Fatalf("err: %s", err)
+	}
+
+	deps := state.Modules[0].Resources["aws_instance.other"].Dependencies
+	if len(deps) > 1 || deps[0] != "aws_instance.create" {
+		t.Fatalf("expected 1 depends_on entry for aws_instance.create, got %q", deps)
+	}
+}
diff --git a/terraform/state_test.go b/terraform/state_test.go
index c10ebf133a..324ab79706 100644
--- a/terraform/state_test.go
+++ b/terraform/state_test.go
@@ -1898,6 +1898,62 @@ func TestReadState_prune(t *testing.T) {
 	}
 }
 
+func TestReadState_pruneDependencies(t *testing.T) {
+	state := &State{
+		Serial:  9,
+		Lineage: "5d1ad1a1-4027-4665-a908-dbe6adff11d8",
+		Remote: &RemoteState{
+			Type: "http",
+			Config: map[string]string{
+				"url": "http://my-cool-server.com/",
+			},
+		},
+		Modules: []*ModuleState{
+			&ModuleState{
+				Path: rootModulePath,
+				Dependencies: []string{
+					"aws_instance.bar",
+					"aws_instance.bar",
+				},
+				Resources: map[string]*ResourceState{
+					"foo": &ResourceState{
+						Dependencies: []string{
+							"aws_instance.baz",
+							"aws_instance.baz",
+						},
+						Primary: &InstanceState{
+							ID: "bar",
+						},
+					},
+				},
+			},
+		},
+	}
+	state.init()
+
+	buf := new(bytes.Buffer)
+	if err := WriteState(state, buf); err != nil {
+		t.Fatalf("err: %s", err)
+	}
+
+	actual, err := ReadState(buf)
+	if err != nil {
+		t.Fatalf("err: %s", err)
+	}
+
+	// make sure the duplicate Dependencies are filtered
+	modDeps := actual.Modules[0].Dependencies
+	resourceDeps := actual.Modules[0].Resources["foo"].Dependencies
+
+	if len(modDeps) > 1 || modDeps[0] != "aws_instance.bar" {
+		t.Fatalf("expected 1 module depends_on entry, got %q", modDeps)
+	}
+
+	if len(resourceDeps) > 1 || resourceDeps[0] != "aws_instance.baz" {
+		t.Fatalf("expected 1 resource depends_on entry, got  %q", resourceDeps)
+	}
+}
+
 func TestResourceNameSort(t *testing.T) {
 	names := []string{
 		"a",
diff --git a/terraform/test-fixtures/apply-multi-ref/main.tf b/terraform/test-fixtures/apply-multi-ref/main.tf
new file mode 100644
index 0000000000..2a6a671521
--- /dev/null
+++ b/terraform/test-fixtures/apply-multi-ref/main.tf
@@ -0,0 +1,8 @@
+resource "aws_instance" "create" {
+	bar = "abc"
+}
+
+resource "aws_instance" "other" {
+	var = "${aws_instance.create.id}"
+    foo = "${aws_instance.create.bar}"
+}