Dashboard crashes when report doesn't contain rows

[eugene-manuilov]

Bug Description

During testing the plugin on my local machine, I encountered a situation when Google Analytics API returns a report with an empty rows property. I suspect it happens because the selected Analytics account has no data, which is fine. What is not fine is that the DashboardSearchVisitorsWidget widget tries to access the report data rows length without checking whether rows is an actual array:

site-kit-wp/assets/js/modules/analytics/components/dashboard/DashboardSearchVisitorsWidget.js

Lines 174 to 182 in 0c40e3a

	const dataRows = sparkData[ 0 ].data.rows;
	// Loop the rows to build the chart data.
	for ( let i = 0; i < dataRows.length; i++ ) {
	const { values } = dataRows[ i ].metrics[ 0 ];
	const dateString = dataRows[ i ].dimensions[ 0 ];
	const date = parseDimensionStringToDate( dateString );
	sparkLineData.push( [ date, values[ 0 ] ] );
	}

This leads to fatal errors and the whole dashboard crashes. We need to make sure that widgets display zero states if there are no rows in the report data.

Additional details:

Report arguments

metrics[0][expression]: ga:users
metrics[0][alias]: Users
dimensions[0][name]: ga:date
dimensions[1][name]: ga:channelGrouping
startDate: 2021-08-05
endDate: 2021-09-01
dimensionFilters[ga:channelGrouping]: Organic Search

Report response

[
  {
    "nextPageToken": null,
    "columnHeader": {
      "dimensions": [
        "ga:date",
        "ga:channelGrouping"
      ],
      "metricHeader": {
        "metricHeaderEntries": [
          {
            "name": "Users",
            "type": "INTEGER"
          }
        ]
      }
    },
    "data": {
      "dataLastRefreshed": null,
      "isDataGolden": null,
      "rowCount": null,
      "samplesReadCounts": null,
      "samplingSpaceSizes": null,
      "totals": [
        {
          "values": [
            "0"
          ]
        }
      ]
    }
  }
]

Screenshots

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Acceptance criteria

• Dashboard widgets should not raise fatal errors if zero rows are returned from the API
  • This is possible with Analytics even when includeEmptyRows is enabled for a request.

Implementation Brief

• Inside assets/js/modules/analytics/components/dashboard/DashboardSearchVisitorsWidget.js, default the dataRows assignment to an empty array if the sparkData array is empty, for example by using optional chaining:

  const dataRows = sparkData?.[ 0 ]?.data?.rows || [];

• Inside site-kit-wp/assets/js/modules/analytics/components/dashboard/DashboardGoalsWidget.js, repeat the step above to default the dataRows assignment on line 164 to an empty array.

Test Coverage

• No new tests required.

Visual Regression Changes

• None anticipated.

QA Brief

• Similar to Dashboard search visitors widget uses incorrect condition for whether to display zero data state #3880, to recreate the issue you will need observe the Unique Visitors from Search widget and the Goals widget under the search funnel section of the dashboard in situations where their reports contain empty rows. For example:
  • Zero total users, including from search
  • One or more total users, but none from search

Changelog entry

• N/A

[johnPhillips]

Note: this is possibly related to #3880

[eugene-manuilov]

Thanks, @johnPhillips. Looks like the same problem exists in the DashboardGoalsWidget component. Let's take care of it too.

site-kit-wp/assets/js/modules/analytics/components/dashboard/DashboardGoalsWidget.js

Line 164 in f54254f

const dataRows = data[ 0 ].data.rows;

[johnPhillips]

Thanks @eugene-manuilov, good catch. I just spent a bit of time looking for any more but I think that's all of them now. I'll update the IB with this one 👍

[eugene-manuilov]

IB ✔️

[johnPhillips]

Note: I ended up implementing this as part of #3880 as there was some overlap with that issue. Moving to QA.

[wpdarren]

QA Update: ✅

For the Unique Visitors from Search and Goals Completed widgets:

• Can confirm that Zero total users loaded with no errors.
• Can confirm that One or more total users, but none from search loaded with no errors.