added findItemsByProduct support

demo/findingApi.js

@@ -35,6 +35,17 @@ ebay.findCompletedItems({
     console.log(error);
 });
 
+// This call searches for items on eBay using specific eBay product values.
+// https://developer.ebay.com/DevZone/finding/CallRef/findItemsByProduct.html#findItemsByProduct
+ebay.findItemsByProduct({
+    productId: 53039031,
+    entriesPerPage: 2
+}).then((data) => {
+    console.log(data);
+}, (error) => {
+    console.log(error);
+});
+
 ebay.getVersion().then((data) => {
     console.log(data.version);
 }, (error) => {

src/findingApi.js

@@ -4,13 +4,12 @@ const urlObject = require('./buildURL');
 const { getRequest } = require('./request');
 
 const findItemsByKeywords = function (options) {
-    if (!options || !options.keywords) {
+    if (!options) {
         throw new Error('Keyword is missing, Keyword is required');
     }
-
     this.options.operationName = 'findItemsByKeywords';
     this.options.param = 'keywords';
-
+    // support only keyword string.
     if (!options.keywords) {
         this.options.name = options;
     }
@@ -42,6 +41,11 @@ const findItemsByCategory = function (categoryID) {
     );
 };
 
+/**
+ * searches for items whose listings are completed and are no longer available for
+ * sale by category (using categoryId), by keywords (using keywords), or a combination of the two.
+ * @param {Object} options
+ */
 const findCompletedItems = function (options) {
     if (!options) throw new Error('Keyword or category ID are required.');
     if (!options.keywords && !options.categoryId) throw new Error('Keyword or category ID are required.');
@@ -58,6 +62,7 @@ const findCompletedItems = function (options) {
     );
 };
 
+
 const getVersion = function () {
     this.options.operationName = 'getVersion';
     const url = urlObject.buildSearchUrl(this.options);
@@ -67,6 +72,24 @@ const getVersion = function () {
     );
 };
 
+/**
+ * Searches for items on eBay using specific eBay product values.
+ * @param {Object} options
+ */
+const findItemsByProduct = function (options) {
+    if (!options) throw new Error('Please enter the Valid input.');
+    if (!options.productId) throw new Error('Product ID is required.');
+    this.options.operationName = 'findItemsByProduct';
+    this.options.additionalParam = constructAdditionalParams(options);
+    let url = urlObject.buildSearchUrl(this.options);
+    url = `${url}&productId.@type=ReferenceID`;
+    return getRequest(url).then((data) => {
+        return JSON.parse(data).findItemsByProductResponse;
+
+    }, console.error
+    );
+};
+
 const constructAdditionalParams = (options) => {
     let params = '';
     let count = 0;
@@ -75,7 +98,7 @@ const constructAdditionalParams = (options) => {
             if (key === 'entriesPerPage' || key === 'pageNumber') {
                 params = `${params}paginationInput.${key}=${options[key]}&`;
             }
-            else if (key === 'keywords' || key === 'categoryId' || key === 'sortOrder') {
+            else if (key === 'keywords' || key === 'categoryId' || key === 'productId' || key === 'sortOrder') {
                 params = `${params}${key}=${options[key]}&`;
             }
             else {
@@ -95,5 +118,6 @@ module.exports = {
     findItemsByCategory,
     findCompletedItems,
     constructAdditionalParams,
+    findItemsByProduct,
     getVersion
 };

src/index.js

@@ -15,6 +15,7 @@ const { getDefaultCategoryTreeId,
 const { findItemsByKeywords,
     findItemsByCategory,
     findCompletedItems,
+    findItemsByProduct,
     getVersion } = require('./findingApi');
 const { setAccessToken,
     getAccessToken,
@@ -63,6 +64,7 @@ Ebay.prototype = {
     findItemsByKeywords,
     findItemsByCategory,
     findCompletedItems,
+    findItemsByProduct,
     getVersion,
     getItem,
     getItemByLegacyId,