Fix error on only updating index.force_destroy.

Closes #61

CHANGELOG.md

@@ -6,6 +6,9 @@
 - Bump terraform plugin sdk to 1.12.0.
 - Add aws profile authentication option
 
+### Fixed
+- Fix error on only updating index.force_destroy.
+
 ## [1.1.1] - 2020-05-09
 ### Added
 - Make ping to elasticsearch during provider config optional

es/resource_elasticsearch_index.go

@@ -256,6 +256,12 @@ func resourceElasticsearchIndexUpdate(d *schema.ResourceData, meta interface{})
 			settings[key] = d.Get(key)
 		}
 	}
+
+	// if we're not changing any settings, no-op this function
+	if len(settings) == 0 {
+		return resourceElasticsearchIndexRead(d, meta)
+	}
+
 	body := map[string]interface{}{
 		"settings": settings,
 	}

es/resource_elasticsearch_index_test.go

@@ -28,6 +28,14 @@ resource "elasticsearch_index" "test" {
   number_of_shards = 1
   number_of_replicas = 2
 }
+`
+	testAccElasticsearchIndexUpdateForceDestroy = `
+resource "elasticsearch_index" "test" {
+  name = "terraform-test"
+  number_of_shards = 1
+  number_of_replicas = 2
+  force_destroy = true
+}
 `
 )
 
@@ -49,6 +57,12 @@ func TestAccElasticsearchIndex(t *testing.T) {
 					checkElasticsearchIndexUpdated("elasticsearch_index.test"),
 				),
 			},
+			{
+				Config: testAccElasticsearchIndexUpdateForceDestroy,
+				Check: resource.ComposeTestCheckFunc(
+					checkElasticsearchIndexUpdated("elasticsearch_index.test"),
+				),
+			},
 		},
 	})
 }