tldr: Dashboard testing checks that filters return correct data, charts render across browsers, aggregations match the source, and exports are accurate. The visual nature makes some bugs obvious and others nearly invisible.
What dashboard testing covers
Five concerns.
Data accuracy
The number on the dashboard should match the number in the database. Aggregations (sum, count, average, percentiles) should be correct. Test by querying the source directly and comparing.
Filter behavior
Selecting a filter should change the displayed data correctly. Multiple filters combine as expected (AND vs OR). Clearing filters returns to the default view.
Time range handling
Date filters often have edge cases: end-of-month, daylight saving transitions, time-zone boundaries, last-30-days vs current-month.
Chart rendering
Charts should render correctly across browsers and screen sizes. Tooltips show the right values. Hover and click interactions work. Empty states display correctly.
Exports
CSV, Excel, and PDF exports should match what is shown on screen. Sort order, filter state, and visible columns all preserved.
What gets missed
Caching bugs. A dashboard shows stale data because the cache did not invalidate. Hard to spot without specific test cases.
Permission filtering. Different users should see different data. Test with multiple user roles, not just the admin.
Locale formatting. A dashboard in a non-English locale should format dates, numbers, and currencies correctly. See internationalization testing.
Drill-down accuracy. Clicking a chart segment should take the user to a filtered view that matches what they clicked.
Visual regression
Charts are particularly prone to visual regression: a CSS update changes the bar widths, a library update shifts the legend, an axis label gets cut off.
Visual regression tools like Percy, Chromatic, or Bug0's visual diffing catch these by comparing screenshots between deploys.
How AI testing fits
End-to-end dashboard testing combines structured assertions (does this number match) with visual checks (does the chart render correctly). Bug0 handles both: structural verification through DOM analysis plus visual diffing.
FAQs
How do I verify dashboard math?
Run the same aggregation in SQL or against the source data, compare to the dashboard. Automate the comparison.
What about real-time dashboards?
Test refresh logic, including the case where the source data changes mid-render.
How often should dashboard tests run?
On every deploy that touches data or rendering. Visual regression on every PR.
How does Bug0 help with dashboards?
Bug0 tests dashboards by walking the UI, applying filters, and validating displayed values against expected. Visual diffing catches the rendering changes.