DotGraphics allows graph images to be used in tests in any of the FitLibrary fixture. For example, graphs are used in the following DoFixture example:
show | graph |
check | graph |  |
See the .FitSpecifications.FixtureSpecifications for other examples.
Details of how this works appear in a paper (in progress) on Ubiquitous Visual Languages.
This requires that Dot, an open-source graph visualization system, is installed. Dot is available at http://www.graphviz.org.