ReportGenerator 2.1 has just been published as a beta release. This blog post will explain the new feature trend/history charts and some other improvements.
When you use the new command line parameter -historydir:SOME_DIRECTORY each execution of ReportGenerator will generate a XML file containing coverage information. On subsequent executions those files are used to render some trend charts.
Charts are generated in each class report and in the summary report. They show evolution of line and branch overage over time:
The directory used for -historydir should be a persistent directory that is not cleaned between builds, otherwise history will get lost.
Branch coverage is only available if you use OpenCover (version 4.5.3207 and above).
Branch information in class report
The class report now shows a visual indicator for branch coverage. A red/green bar indicates the coverage of a branch.
Feedback is highly appreciated. Let me know if you like the new charts?