backend/local tests tests tests

converted the existing testPlanState() from terraform.State to
states.State to fix various plan tests.

reverted the "bandaid" in plans/planfile/tfplan.go - at this moment the
backend tests do not include backend configuration, and so the planfile
package can write the plan file but not read it back in. That will be
revisted in a separate track of work.

backend/local/backend_plan_test.go

@@ -8,11 +8,13 @@ import (
 	"strings"
 	"testing"
 
+	"github.com/hashicorp/terraform/addrs"
 	"github.com/hashicorp/terraform/backend"
 	"github.com/hashicorp/terraform/configs/configload"
 	"github.com/hashicorp/terraform/configs/configschema"
 	"github.com/hashicorp/terraform/plans"
 	"github.com/hashicorp/terraform/plans/planfile"
+	"github.com/hashicorp/terraform/states"
 	"github.com/hashicorp/terraform/terraform"
 	"github.com/mitchellh/cli"
 	"github.com/zclconf/go-cty/cty"
@@ -133,7 +135,7 @@ func TestLocal_planRefreshFalse(t *testing.T) {
 	defer cleanup()
 
 	p := TestLocalProvider(t, b, "test", planFixtureSchema())
-	terraform.TestStateFile(t, b.StatePath, testPlanState())
+	testStateFile(t, b.StatePath, testPlanState())
 
 	op, configCleanup := testOperationPlan(t, "./test-fixtures/plan")
 	defer configCleanup()
@@ -161,7 +163,7 @@ func TestLocal_planDestroy(t *testing.T) {
 	defer cleanup()
 
 	p := TestLocalProvider(t, b, "test", planFixtureSchema())
-	terraform.TestStateFile(t, b.StatePath, testPlanState())
+	testStateFile(t, b.StatePath, testPlanState())
 
 	outDir := testTempDir(t)
 	defer os.RemoveAll(outDir)
@@ -202,7 +204,7 @@ func TestLocal_planOutPathNoChange(t *testing.T) {
 	b, cleanup := TestLocal(t)
 	defer cleanup()
 	TestLocalProvider(t, b, "test", planFixtureSchema())
-	terraform.TestStateFile(t, b.StatePath, testPlanState())
+	testStateFile(t, b.StatePath, testPlanState())
 
 	outDir := testTempDir(t)
 	defer os.RemoveAll(outDir)
@@ -222,14 +224,10 @@ func TestLocal_planOutPathNoChange(t *testing.T) {
 	}
 
 	plan := testReadPlan(t, planPath)
-	// This statement can be removed when the test is fixed and replaced with the
-	// commented-out test below.
-	if plan == nil {
-		t.Fatalf("plan is nil")
+
+	if !plan.Changes.Empty() {
+		t.Fatalf("expected empty plan to be written")
 	}
-	// if !plan.Changes.Empty() {
-	// 	t.Fatalf("expected empty plan to be written")
-	// }
 }
 
 // TestLocal_planScaleOutNoDupeCount tests a Refresh/Plan sequence when a
@@ -242,29 +240,7 @@ func TestLocal_planScaleOutNoDupeCount(t *testing.T) {
 	b, cleanup := TestLocal(t)
 	defer cleanup()
 	TestLocalProvider(t, b, "test", planFixtureSchema())
-	state := &terraform.State{
-		Version: 2,
-		Modules: []*terraform.ModuleState{
-			&terraform.ModuleState{
-				Path: []string{"root"},
-				Resources: map[string]*terraform.ResourceState{
-					"test_instance.foo.0": &terraform.ResourceState{
-						Type: "test_instance",
-						Primary: &terraform.InstanceState{
-							ID: "bar",
-						},
-					},
-					"test_instance.foo.1": &terraform.ResourceState{
-						Type: "test_instance",
-						Primary: &terraform.InstanceState{
-							ID: "bar",
-						},
-					},
-				},
-			},
-		},
-	}
-	terraform.TestStateFile(t, b.StatePath, state)
+	testStateFile(t, b.StatePath, testPlanState())
 
 	actual := new(CountHook)
 	b.ContextOpts.Hooks = append(b.ContextOpts.Hooks, actual)
@@ -309,24 +285,32 @@ func testOperationPlan(t *testing.T, configDir string) (*backend.Operation, func
 	}, configCleanup
 }
 
-// testPlanState is just a common state that we use for testing refresh.
-func testPlanState() *terraform.State {
-	return &terraform.State{
-		Version: 2,
-		Modules: []*terraform.ModuleState{
-			&terraform.ModuleState{
-				Path: []string{"root"},
-				Resources: map[string]*terraform.ResourceState{
-					"test_instance.foo": &terraform.ResourceState{
-						Type: "test_instance",
-						Primary: &terraform.InstanceState{
-							ID: "bar",
-						},
-					},
-				},
-			},
+// testPlanState is just a common state that we use for testing plan.
+func testPlanState() *states.State {
+	state := states.NewState()
+	rootModule := state.RootModule()
+	rootModule.SetResourceInstanceCurrent(
+		addrs.Resource{
+			Mode: addrs.ManagedResourceMode,
+			Type: "test_instance",
+			Name: "foo",
+		}.Instance(addrs.IntKey(0)),
+		&states.ResourceInstanceObjectSrc{
+			Status:        states.ObjectReady,
+			SchemaVersion: 1,
+			AttrsJSON: []byte(`{
+				"ami": "bar",
+				"network_interface": [{
+					"device_index": 0,
+					"description": "Main network interface"
+				}]
+			}`),
 		},
-	}
+		addrs.ProviderConfig{
+			Type: "test",
+		}.Absolute(addrs.RootModuleInstance),
+	)
+	return state
 }
 
 func testReadPlan(t *testing.T, path string) *plans.Plan {

backend/local/test-fixtures/plan-scaleout/main.tf

@@ -1,5 +1,5 @@
 resource "test_instance" "foo" {
-  count = 3
+  count = 2
   ami   = "bar"
 
   # This is here because at some point it caused a test failure

backend/local/testing.go

@@ -8,6 +8,7 @@ import (
 
 	"github.com/hashicorp/terraform/backend"
 	"github.com/hashicorp/terraform/providers"
+	"github.com/hashicorp/terraform/states"
 	"github.com/hashicorp/terraform/states/statemgr"
 	"github.com/hashicorp/terraform/terraform"
 	"github.com/hashicorp/terraform/tfdiags"
@@ -61,12 +62,6 @@ func TestLocalProvider(t *testing.T, b *Local, name string, schema *terraform.Pr
 			PlannedPrivate: req.PriorPrivate,
 		}
 	}
-	p.DiffFn = func(
-		info *terraform.InstanceInfo,
-		s *terraform.InstanceState,
-		r *terraform.ResourceConfig) (*terraform.InstanceDiff, error) {
-		return nil, nil
-	}
 	p.ReadResourceFn = func(req providers.ReadResourceRequest) providers.ReadResourceResponse {
 		return providers.ReadResourceResponse{NewState: req.PriorState}
 	}
@@ -171,3 +166,8 @@ func testTempDir(t *testing.T) string {
 
 	return d
 }
+
+func testStateFile(t *testing.T, path string, s *states.State) {
+	stateFile := statemgr.NewFilesystem(path)
+	stateFile.WriteState(s)
+}

plans/planfile/tfplan.go

@@ -277,10 +277,6 @@ func changeFromTfplan(rawChange *planproto.Change) (*plans.ChangeSrc, error) {
 }
 
 func valueFromTfplan(rawV *planproto.DynamicValue) (plans.DynamicValue, error) {
-	if rawV.Msgpack == nil {
-		return plans.DynamicValue(nil), nil
-	}
-
 	if len(rawV.Msgpack) == 0 { // len(0) because that's the default value for a "bytes" in protobuf
 		return nil, fmt.Errorf("dynamic value does not have msgpack serialization")
 	}