handle when state does not exist (#2659)

Author: skarimo

datadog/resource_datadog_synthetics_test_.go

@@ -2877,9 +2877,12 @@ func buildDatadogBodyFiles(attr []interface{}) []datadogV1.SyntheticsTestRequest
 func buildTerraformBodyFiles(actualBodyFiles *[]datadogV1.SyntheticsTestRequestBodyFile, oldLocalBodyFiles []map[string]interface{}) (localBodyFiles []map[string]interface{}) {
 	localBodyFiles = make([]map[string]interface{}, len(*actualBodyFiles))
 	for i, file := range *actualBodyFiles {
-		// The file content is kept from the existing localFile from the state,
-		// as the response from the backend contains the bucket key rather than the content.
-		localFile := oldLocalBodyFiles[i]
+		localFile := make(map[string]interface{})
+		if i < len(oldLocalBodyFiles) && oldLocalBodyFiles[i] != nil {
+			// The file content is kept from the existing localFile from the state,
+			// as the response from the backend contains the bucket key rather than the content.
+			localFile = oldLocalBodyFiles[i]
+		}
 		localFile["name"] = file.GetName()
 		localFile["original_file_name"] = file.GetOriginalFileName()
 		localFile["type"] = file.GetType()