Testing Inkscape

Inkscape is a young project and the emphasis is still on adding features. Nonetheless it is gratifying that the stability of Inkspace has been steadily rising with each release.

The most important part of 'Testing' is simply to use Inkscape for normal work -- confirming that Inkscape has reached this level of maturity, exercise the new features and verify that the application works as expected.

Report a bug if you find anything that does not behave as it should. A bug report should include at least a step-by-step description of how to trigger the bug and/or a test file that demonstrates the bug (the smaller/more focussed the test file the better).


The field is wide open. We are keen to receive bug reports and feature requests (in the form of a bug report). These often require analysis, clarification and further action. Anyone can do this.

Better still would be to provide patches for any part of the application that is not up to the standard you expect - it is confirmation that the project is evolving. Note that serious testing should be done with an 'unstable' build, either one that you made yourself (see CompilingInkscape), or a snapshot that you have downloaded. We would also like to hear about areas in which we do not have parity with comparable applications. If you find that you are coming up with interesting ideas concerning shortcomings in Inkscape, or plans for its future, get involved with the Inkscape testers group.

We need people to create and update documentation, online help, tutorials and screen shots. Noting defects in these is a perfectly valid form of testing - we do not want releases to go out with obsolete documentation.

Inkscape Testers

A community of Inkscape testers has grown up which has its own mailing list, and it is to be hoped that this will spearhead all work on usability and human factors. This group should be your first port of call for these areas:

See also TestingFramework. Note: Bryce? Jon? shouldn't the whole of that page be merged here? Or is it better to have this info in two pieces. IMHO wiki pages should not be made too long.

Rendering tests

In addition, Inkscape has rendering tests that do not necessarily need a developer to create, run and analyze. The actual tests can be found in SVN (see below). Below you can find information on how to run and create these tests yourself.

See this list for up-to-date results.

Running rendering tests

Apart from running low-level unit tests Inkscape can also be tested on a higher level (also see SVG Test Suite Compliance). Currently (2008-7-26) there is a rendering test tool (along with a few test cases) in SVN which can be used to partially automate rendering tests.

To run the rendering tests:

Note that by default only a binary comparison between the output and reference files is used, perceptualdiff (or any other comparison tool that returns zero on success and 1 on failure) can be used to aid comparison of images (see the available options of Note that perceptualdiff (1.0.2) had some problems with transparency, these might be solved by now, and if not, there is a patch in its patch tracker.

To select a subset of tests to perform, specify one or more patterns (with Unix-style wildcards) on the command line. Each pattern is interpreted as specifying a prefix. For example, ' bugs' will match any tests whose path relative to the directory with test cases starts with 'bugs' (for example: 'bugsy.svg' or 'bugs/bugXYZ.svg').

The most common test results are: puts the output files in a subdirectory 'output' (at the same level as the 'testcases' and 'references' directories).

Creating rendering tests

Just put an SVG file in the 'testcases' directory (subdirectories can be used for organizing the tests).

To add a pass/fail reference, just put it in the corresponding location under references/pass or references/fail. References are matched by prefix, so any reference that has the original name (without its extension) as a prefix is seen as a reference for that file.

Fail references are used to distinguish between a result that is known wrong and a result that is just (perhaps only slightly) different from the correct rendering. If you are unable to create a pass reference you can even give just a fail reference.

It is also possible to create an SVG file that should produce the exact same output as a test case but uses simpler (or just different) methods. This practice is suggested in the SVG Conformance Test Plan. For example, if the test case file is called 'testcases/basic/foo.svg' you could create a "patch" file called 'testcases/basic/foo-patch.svg'. would then use Inkscape to create a pass reference file from that (as 'references/pass/basic/foo-patch.svg') and use it as one of the references. (Note that this reference should in general not be committed to SVN.)


Build report

There is an 'inkscape build report; which is sent regularly to the inkscape-tester list (and periodically to the developer list, when new problems are seen) that gives a count of warnings spotted in the code.

Running unit tests

There are now some unit tests which should be performed before checking in. These may take some time to complete, and so this cannot be made a requirement for each build (Test Driven Development), nonetheless everyone is on their honour not to 'break the build' by committing code that does not pass these tests. You can execute them by:

Cxxtests will generate two (more or less equivalent) result files, an XML file and a text file with the extension 'log'. On Linux, those files are located in (buildpath)/src.

Creating unit tests

Inkscape uses the CxxTest framework. To enhance, modify or extend existing unit tests, just edit the existing test file (....-test.h).

The easiest way to create a new test in a directory which already has some unit tests is to simply copy one of the existing test files, strip it (remove anything specific and rename the class, constructors, etc.) and add some test methods. Take the time to look at the different ASSERT statements CxxTest supports, the TSM_ variants can be especially useful for example when you want to test a lot of different cases. Important: to make everything build correctly you have to do the following:

# Do like this:
    $(srcdir)/dir/first-test.h \

For creating a unit test in a directory which does not have any unit tests yet:

Running tests unattended

For unit tests this is no problem, just set up something that runs cxxtests and you can use one of the log files it creates to see how it went.

To be able to run the rendering tests unattended on Windows you have to compile Inkscape as a commandline executable to prevent any CRT runtime error dialog boxes (or something similar) from popping up. On Linux and other Unices, this problem doesn't exist.

The teststatus.json file that is generated by contains all the test results (in JSON format). Note that if you only run a subset of the tests this file retains all the information on tests that do not fall into that subset. It also retains old test results. The result codes in this file can be interpreted as in (for example, 0, 1 and 2 stand for pass, fail and new, respectively).

Analyzing test coverage

To see how well the (unit) tests cover certain parts of the code, or to compare the coverage of rendering tests vs. unit tests, gcov can be used. See Profiling for more information on how to use gcov and (a tool to get some grip on the massive amounts of data gcov can generate).