From b02473541a7ed7b85ee5e830fcbcd758313ccc5e Mon Sep 17 00:00:00 2001
From: zengling-zingbox <36426752+zengling-zingbox@users.noreply.github.com>
Date: Sun, 10 Jan 2021 08:35:20 +0800
Subject: [PATCH] filter out null objects (#398)

---
 src/extractor.ts | 9 +++++----
 1 file changed, 5 insertions(+), 4 deletions(-)

diff --git a/src/extractor.ts b/src/extractor.ts
index f128f4e5..5d4449f3 100644
--- a/src/extractor.ts
+++ b/src/extractor.ts
@@ -253,7 +253,7 @@ export function extract(context: string, fields) {
         index: ['Name'],
         attributePath: ['AttributeValue'],
         attributes: []
-      } 
+      }
     */
     if (index && attributePath) {
       // find the index in localpath
@@ -309,7 +309,7 @@ export function extract(context: string, fields) {
         value = node[0].toString();
       }
       if (node.length > 1) {
-        value = node.map(n => n.toString()); 
+        value = node.map(n => n.toString());
       }
       return {
         ...result,
@@ -330,7 +330,7 @@ export function extract(context: string, fields) {
       const childXPath = `${buildAbsoluteXPath([last(localPath)])}${attributeXPath}`;
       const attributeValues = baseNode.map((node: string) => {
         const nodeDoc = new dom().parseFromString(node);
-        const values = select(childXPath, nodeDoc).reduce((r: any, n: Attr) => { 
+        const values = select(childXPath, nodeDoc).reduce((r: any, n: Attr) => {
           r[camelCase(n.name)] = n.value;
           return r;
         }, {});
@@ -373,7 +373,8 @@ export function extract(context: string, fields) {
         attributeValue = select(fullPath, targetDoc);
       }
       if (node.length > 1) {
-        attributeValue = node.map((n: Node) => n.firstChild!.nodeValue);
+        attributeValue = node.filter((n: Node) => n.firstChild)
+          .map((n: Node) => n.firstChild!.nodeValue);
       }
       return {
         ...result,