reduce instead of for

Author: mohawk2

src/execution/execute.js

@@ -1098,15 +1098,11 @@ function completeListValue(
 function flattenEPRs(
   eprs: $ReadOnlyArray<ExecutionPartialResultNP<mixed>>,
 ): ExecutionPartialResultNP<mixed> {
-  const errors = [];
-  const data = [];
-  for (let i = eprs.length - 1; i >= 0; i--) {
-    data[i] = eprs[i][0];
-    if (eprs[i][1] && eprs[i][1].length) {
-      errors.push(...eprs[i][1]);
-    }
-  }
-  return [data, errors.length ? errors.reverse() : null];
+  const errors = eprs.reduce(
+    (m, i) => (i[1] && i[1].length ? [...m, ...i[1]] : m),
+    [],
+  );
+  return [eprs.map(i => i[0]), errors.length ? errors : null];
 }
 
 /**