Merge pull request #1824 from hashicorp/b-write-count-for-empty-maps

helper/schema: write "attr.#": "0" for empty maps

helper/schema/field_writer_map.go

@@ -141,7 +141,12 @@ func (w *MapFieldWriter) setMap(
 	v := reflect.ValueOf(value)
 	vs := make(map[string]interface{})
 
-	if value != nil {
+	if value == nil {
+		// The empty string here means the map is removed.
+		w.result[k] = ""
+		return nil
+	}
+
 	if v.Kind() != reflect.Map {
 		return fmt.Errorf("%s: must be a map", k)
 	}
@@ -152,13 +157,6 @@ func (w *MapFieldWriter) setMap(
 		mv := v.MapIndex(mk)
 		vs[mk.String()] = mv.Interface()
 	}
-	}
-
-	if len(vs) == 0 {
-		// The empty string here means the map is removed.
-		w.result[k] = ""
-		return nil
-	}
 
 	// Remove the pure key since we're setting the full map value
 	delete(w.result, k)

helper/schema/resource_data_test.go

@@ -2539,7 +2539,9 @@ func TestResourceDataState(t *testing.T) {
 			},
 
 			Result: &terraform.InstanceState{
-				Attributes: map[string]string{},
+				Attributes: map[string]string{
+					"tags.#": "0",
+				},
 			},
 		},