Persist time queries when clicking on breadcrumbs links (https://github.com/woocommerce/woocommerce-admin/pull/759)

* Make breadcrumbs links persist date queries

* Add tests to getTimeRelatedQuery() when query parameter not set

* Add comment explanation about navUtils self-import

plugins/woocommerce-admin/client/header/index.js

@@ -15,6 +15,7 @@ import PropTypes from 'prop-types';
 import './style.scss';
 import ActivityPanel from './activity-panel';
 import { Link } from '@woocommerce/components';
+import { getNewPath, getTimeRelatedQuery } from 'lib/nav-utils';
 
 class Header extends Component {
 	constructor() {
@@ -83,7 +84,10 @@ class Header extends Component {
 					</span>
 					{ _sections.map( ( section, i ) => {
 						const sectionPiece = Array.isArray( section ) ? (
-							<Link href={ section[ 0 ] } type={ isEmbedded ? 'wp-admin' : 'wc-admin' }>
+							<Link
+								href={ getNewPath( getTimeRelatedQuery(), section[ 0 ], {} ) }
+								type={ isEmbedded ? 'wp-admin' : 'wc-admin' }
+							>
 								{ section[ 1 ] }
 							</Link>
 						) : (

plugins/woocommerce-admin/client/lib/nav-utils/index.js

@@ -6,6 +6,12 @@ import history from 'lib/history';
 import { parse, stringify } from 'qs';
 import { isEmpty, pick, uniq } from 'lodash';
 
+/**
+ * Internal dependencies
+ */
+// Import the module into itself. Functions consumed from this import can be mocked in tests.
+import * as navUtils from './index';
+
 /**
  * Returns a string with the site's wp-admin URL appended. JS version of `admin_url`.
  *
@@ -35,7 +41,7 @@ export const stringifyQuery = query => ( isEmpty( query ) ? '' : '?' + stringify
  * @param {Object} query Query containing the parameters.
  * @return {Object} Object containing the time related queries.
  */
-export const getTimeRelatedQuery = query =>
+export const getTimeRelatedQuery = ( query = navUtils.getQuery() ) =>
 	pick( query, [ 'period', 'compare', 'before', 'after' ] );
 
 /**

plugins/woocommerce-admin/client/lib/nav-utils/test/index.js

@@ -4,6 +4,18 @@
  */
 import { getTimeRelatedQuery } from '../index';
 
+jest.mock( '../index', () => ( {
+	...require.requireActual( '../index' ),
+	getQuery: jest.fn().mockReturnValue( {
+		filter: 'advanced',
+		product_includes: 127,
+		period: 'year',
+		compare: 'previous_year',
+		after: '2018-02-01',
+		before: '2018-01-01',
+	} ),
+} ) );
+
 describe( 'getTimeRelatedQuery', () => {
 	it( "should return an empty object it the query doesn't contain any time related parameters", () => {
 		const query = {
@@ -33,4 +45,15 @@ describe( 'getTimeRelatedQuery', () => {
 
 		expect( getTimeRelatedQuery( query ) ).toEqual( timeRelatedQuery );
 	} );
+
+	it( 'should get the query from getQuery() when none is provided in the params', () => {
+		const timeRelatedQuery = {
+			period: 'year',
+			compare: 'previous_year',
+			after: '2018-02-01',
+			before: '2018-01-01',
+		};
+
+		expect( getTimeRelatedQuery() ).toEqual( timeRelatedQuery );
+	} );
 } );