helper/schema: SetDependencies

helper/schema/resource_data.go

@@ -5,6 +5,7 @@ import (
 	"reflect"
 	"strconv"
 	"strings"
+	"sync"
 
 	"github.com/hashicorp/terraform/terraform"
 	"github.com/mitchellh/mapstructure"
@@ -29,6 +30,7 @@ type ResourceData struct {
 
 	setMap   map[string]string
 	newState *terraform.ResourceState
+	once     sync.Once
 }
 
 // Get returns the data for the given key, or nil if the key doesn't exist.
@@ -93,14 +95,30 @@ func (d *ResourceData) Id() string {
 	return result
 }
 
+// Dependencies returns the dependencies in this state.
+func (d *ResourceData) Dependencies() []terraform.ResourceDependency {
+	if d.newState != nil {
+		return d.newState.Dependencies
+	}
+
+	if d.state != nil {
+		return d.state.Dependencies
+	}
+
+	return nil
+}
+
 // SetId sets the ID of the resource. If the value is blank, then the
 // resource is destroyed.
 func (d *ResourceData) SetId(v string) {
-	if d.newState == nil {
+	d.once.Do(d.init)
-		d.newState = new(terraform.ResourceState)
+	d.newState.ID = v
 }
 
-	d.newState.ID = v
+// SetDependencies sets the dependencies of a resource.
+func (d *ResourceData) SetDependencies(ds []terraform.ResourceDependency) {
+	d.once.Do(d.init)
+	d.newState.Dependencies = ds
 }
 
 // State returns the new ResourceState after the diff and any Set
@@ -109,10 +127,20 @@ func (d *ResourceData) State() *terraform.ResourceState {
 	var result terraform.ResourceState
 	result.ID = d.Id()
 	result.Attributes = d.stateObject("", d.schema)
+	result.Dependencies = d.Dependencies()
 
 	return &result
 }
 
+func (d *ResourceData) init() {
+	var copyState terraform.ResourceState
+	if d.state != nil {
+		copyState = *d.state
+	}
+
+	d.newState = &copyState
+}
+
 func (d *ResourceData) get(
 	k string,
 	parts []string,

helper/schema/resource_data_test.go

@@ -1192,6 +1192,22 @@ func TestResourceDataState(t *testing.T) {
 	}
 }
 
+func TestResourceDataSetDependencies(t *testing.T) {
+	d := &ResourceData{}
+	d.SetDependencies([]terraform.ResourceDependency{
+		terraform.ResourceDependency{ID: "foo"},
+	})
+
+	expected := []terraform.ResourceDependency{
+		terraform.ResourceDependency{ID: "foo"},
+	}
+
+	actual := d.State()
+	if !reflect.DeepEqual(actual.Dependencies, expected) {
+		t.Fatalf("bad: %#v", actual)
+	}
+}
+
 func TestResourceDataSetId(t *testing.T) {
 	d := &ResourceData{}
 	d.SetId("foo")