terraform: ResourceState contains type

terraform/state.go

@@ -32,6 +32,7 @@ func (s *State) init() {
 // for later, but is not exposed in any way to the user.
 type ResourceState struct {
 	ID         string
+	Type       string
 	Attributes map[string]string
 	Extra      map[string]interface{}
 }

terraform/terraform.go

@@ -162,12 +162,20 @@ func (t *Terraform) diffWalkFn(
 		if state != nil {
 			rs = state.resources[r.Id()]
 		}
+		l.RUnlock()
+
 		if len(vars) > 0 {
 			if err := r.RawConfig.Interpolate(vars); err != nil {
 				panic(fmt.Sprintf("Interpolate error: %s", err))
 			}
 		}
-		l.RUnlock()
+
+		// If we have no state, then create an empty state with the
+		// type fulfilled at the least.
+		if rs == nil {
+			rs = new(ResourceState)
+		}
+		rs.Type = r.Type
 
 		diff, err := p.Provider.Diff(rs, &ResourceConfig{
 			ComputedKeys: r.RawConfig.UnknownKeys(),

terraform/terraform_test.go

@@ -292,10 +292,15 @@ func testProviderFunc(n string, rs []string) ResourceProviderFactory {
 
 	return func() (ResourceProvider, error) {
 		diffFn := func(
-			_ *ResourceState,
+			s *ResourceState,
 			c *ResourceConfig) (*ResourceDiff, error) {
 			var diff ResourceDiff
 			diff.Attributes = make(map[string]*ResourceAttrDiff)
+			diff.Attributes["type"] = &ResourceAttrDiff{
+				Old: "",
+				New: s.Type,
+			}
+
 			for k, v := range c.Raw {
 				if _, ok := v.(string); !ok {
 					continue
@@ -419,15 +424,19 @@ func testTerraformProvider(tf *Terraform, n string) *terraformProvider {
 
 const testTerraformDiffStr = `
 UPDATE: aws_instance.bar
-  foo: "" => "2"
+  foo:  "" => "2"
+  type: "" => "aws_instance"
 UPDATE: aws_instance.foo
-  num: "" => "2"
+  num:  "" => "2"
+  type: "" => "aws_instance"
 `
 
 const testTerraformDiffComputedStr = `
 UPDATE: aws_instance.bar
-  foo: "" => "<computed>"
+  foo:  "" => "<computed>"
+  type: "" => "aws_instance"
 UPDATE: aws_instance.foo
-  id:  "" => "<computed>"
-  num: "" => "2"
+  id:   "" => "<computed>"
+  num:  "" => "2"
+  type: "" => "aws_instance"
 `