Fix row evolution for reports where visits metric is not available (#…

…22239)

* Fix row evolution for reborts where visits metric is not available

* Add UI test

plugins/API/RowEvolution.php

@@ -63,9 +63,14 @@ public function getRowEvolution($idSite, $period, $date, $apiModule, $apiAction,
 
         // if goal metrics should be shown, we replace the metrics
         if ($showGoalMetricsForGoal !== false) {
-            $metadata['metrics'] = [
-                'nb_visits' => $metadata['metrics']['nb_visits'],
-            ];
+            if (array_key_exists('nb_visits', $metadata['metrics'])) {
+                $metadata['metrics'] = [
+                    'nb_visits' => $metadata['metrics']['nb_visits'],
+                ];
+            } else {
+                // if no visits are available, simply use the first available metric
+                $metadata['metrics'] = array_slice($metadata['metrics'], 0, 1);
+            }
 
             // Use ecommerce specific metrics / column names when only showing ecommerce metrics
             if ($showGoalMetricsForGoal === Piwik::LABEL_ID_GOAL_IS_ECOMMERCE_ORDER) {

plugins/Goals/tests/UI/Goals_spec.js

@@ -95,6 +95,19 @@ describe("Goals", function () {
         expect(await report.screenshot()).to.matchImage('goals_by_entry_page_titles');
     });
 
+    it('should load row evolution with goal metrics', async function() {
+        const row = await page.waitForSelector('.reportsByDimensionView tbody tr:first-child');
+        await row.hover();
+
+        const icon = await page.waitForSelector('.reportsByDimensionView tbody tr:first-child a.actionRowEvolution');
+        await icon.click();
+
+        await page.waitForSelector('.ui-dialog');
+        await page.waitForNetworkIdle();
+
+        const dialog = await page.$('.ui-dialog');
+        expect(await dialog.screenshot()).to.matchImage('goals_by_entry_page_titles_row_evolution');
+    });
 
     it('should show action goals visualization for page urls', async function() {