Fix null values in CSV columns export (https://github.com/woocommerce/woocommerce-admin/pull/1652)

* Fix null values in CSV columns export

* Check if value is null or undefined to avoid falsey for 0 values

* Add null value to CSV tests

* Improve changelog message

plugins/woocommerce-admin/packages/components/src/table/__mocks__/table-mock-csv.js

@@ -2,4 +2,4 @@
 
 export default `Date,Orders,Gross Revenue,Refunds,Taxes,Shipping,Net Revenue
 2018-10-01 00:00:00,1,411,0,0,0,411
-2018-10-02 00:00:00,0,0,0,0,0,0`;
+2018-10-02 00:00:00,0,0,,0,0,0`;

plugins/woocommerce-admin/packages/components/src/table/__mocks__/table-mock-data.js

@@ -50,7 +50,7 @@ export default [
 		},
 		{
 			display: '€0.00',
-			value: 0,
+			value: null,
 		},
 		{
 			display: '€0.00',

plugins/woocommerce-admin/packages/csv-export/CHANGELOG.md

@@ -1,3 +1,7 @@
+# 1.1.0
+
+- Fix error in `getCSVRows` when there is a null or undefined column value
+
 # 1.0.0
 
 - Released package

plugins/woocommerce-admin/packages/csv-export/src/index.js

@@ -13,7 +13,9 @@ function getCSVRows( rows ) {
 	return Array.isArray( rows )
 		? rows
 				.map( row =>
-					row.map( rowItem => rowItem.value.toString().replace( /,/g, '' ) ).join( ',' )
+					row.map( rowItem =>
+						rowItem.value !== undefined && rowItem.value !== null ? rowItem.value.toString().replace( /,/g, ''
+					) : '' ).join( ',' )
 				)
 				.join( '\n' )
 		: [];