Running FlexUnit 0.9 tests on a headless *nix server

Using continuous builds to provide a constant overview of the health of your code base is a fairly easy to achieve with Flex projects, by using Ant. Running unit tests should ideally also be a part of this process, because developers often won’t run them before every check in. There is no problem running Flex Unit tests on a Windows server but *nix servers are often used as compile servers for a variety of reasons including cost. Flash Player requires a display to run, and most compile servers in my experience don’t have one. It is in fact very easy to get around this problem, by using a piece of software called XVFB (X Virtual Frame Buffer).

XVFB creates a virtual X server which can be used to satisfy Flash Player’s requirement for a display without having a physical display. This is very useful for running FlexUnit tests as it’s not necessary to see flash player running, just to retrieve the test report at the end. You can read more about the ant task here.

xvfb :21 &
export DISPLAY=:21
#Run your tests here, eg, ant runTestsTarget 

These commands will start the virtual server, set it as the current display and run your tests. You can, of course, just start XVFB once and leave it running rather than continuously starting and stopping it on every run of your tests. This simple tool makes running unit tests on a headless *nix server very simple.