Fix for single length arrays not unwinding nested arrays (#165)

* Add a finalPass to unwindRecordsIfNecessary

Author: hdwatts

src/json2csv.js

@@ -159,7 +159,7 @@ const Json2Csv = function(options) {
      * @param params {Object}
      * @returns {Promise}
      */
-    function unwindRecordsIfNecessary(params) {
+    function unwindRecordsIfNecessary(params, finalPass = false) {
         if (options.unwindArrays) {
             const originalRecordsLength = params.records.length;
 
@@ -178,6 +178,12 @@ const Json2Csv = function(options) {
                     }
                     // Otherwise, we didn't unwind any additional arrays, so continue...
 
+                    // Run a final time in case the earlier unwinding exposed additional
+                    // arrays to unwind...
+                    if (!finalPass) {
+                        return unwindRecordsIfNecessary(params, true);
+                    }
+
                     // If keys were provided, set the headerFields to the provided keys:
                     if (options.keys) {
                         params.headerFields = options.keys;

test/config/testCsvFilesList.js

@@ -7,6 +7,7 @@ const fs = require('fs'),
         {key: 'array', file: '../data/csv/array.csv'},
         {key: 'arrayObjects', file: '../data/csv/arrayObjects.csv'},
         {key: 'arrayMixedObjNonObj', file: '../data/csv/arrayMixedObjNonObj.csv'},
+        {key: 'arraySingleArray', file: '../data/csv/arraySingleArray.csv'},
         {key: 'date', file: '../data/csv/date.csv'},
         {key: 'null', file: '../data/csv/null.csv'},
         {key: 'undefined', file: '../data/csv/undefined.csv'},

test/config/testJsonFilesList.js

@@ -4,6 +4,7 @@ module.exports = {
     array: require('../data/json/array'),
     arrayObjects: require('../data/json/arrayObjects'),
     arrayMixedObjNonObj: require('../data/json/arrayMixedObjNonObj'),
+    arraySingleArray: require('../data/json/arraySingleArray'),
     date: require('../data/json/date'),
     null: require('../data/json/null'),
     undefined: require('../data/json/undefined'),

test/data/csv/arraySingleArray.csv

@@ -0,0 +1,2 @@
+list.name,list.features.name,list.features.price.currency,list.features.price.amount
+Shopping List,Television,USD,100

test/data/json/arraySingleArray.json

@@ -0,0 +1,16 @@
+{
+  "list": [
+    {
+      "name": "Shopping List",
+      "features": [
+        {
+          "name": "Television",
+          "price": {
+            "currency": "USD",
+            "amount": 100
+          }
+        }
+      ]
+    }
+  ]
+}

test/json2csv.js

@@ -435,6 +435,16 @@ function runTests(jsonTestData, csvTestData) {
                 });
             });
 
+            it('should unwind nested array values when the earlier array has a length of 1', (done) => {
+                converter.json2csv(jsonTestData.arraySingleArray, (err, csv) => {
+                    if (err) done(err);
+                    csv.should.equal(csvTestData.arraySingleArray);
+                    done();
+                }, {
+                    unwindArrays: true
+                });
+            });
+
             it('should unwind array values when specified - with keys specified', (done) => {
                 converter.json2csv(jsonTestData.unwind, (err, csv) => {
                     if (err) done(err);