What is the Test Results Trend dashboard widget good for in Azure DevOps?

This widget adds a configurable tile that displays the trend of test results for the selected build or release pipeline. The widget helps you visualize the test trends over a period of time, thereby surfacing patterns about test failures, test duration etc.

From the configuration dialog, select the build or release whose test results you'd like to monitor. There are multiple chart options to choose from (Line, Column & Stacked Column) based on your preference. Optionally you can map the trend of test duration on the existing chart by adding a secondary line chart.