Unit Tests for libigl

The libigl unit test are included in the main repository inside the tests folder. There is a CMake flag to enable/disable the testings LIBIGL_BUILD_TESTS which is disabled by default when libigl is not a toplevel project, that is when you are using libigl as a library in your own project.


Before writing any new unit test, be sure you are up-to-date with the master branch to use the latest version of libigl available.


  • Catch2 is an auto-downloaded dependency.

Build And Test

Use cmake to generate a Makefile that will build and test upon issuing make:

mkdir build
cd build
cmake ..

Then build and test with

make test

This will first compile the tests and then immediately run the tests. If tests are succeeding you should see output similar to:

Test project /usr/local/libigl-unit-tests/build
    Start 1: run_igl_mosek_tests
1/4 Test #1: run_igl_mosek_tests ..............***Exception: Other  0.00 sec
    Start 2: run_igl_boolean_tests
2/4 Test #2: run_igl_boolean_tests ............   Passed    1.12 sec
    Start 3: run_igl_cgal_tests
3/4 Test #3: run_igl_cgal_tests ...............   Passed    2.46 sec
    Start 4: run_igl_tests

We refer to the Catch2 manual for additional options.

Generating New Tests

To create a new test, just create a file with the same name of the file you want to test inside the include\igl in the tests folder. Then just add

#include <test_common.h>

TEST_CASE("<function_name> <possible description>", "[igl]")
  //test code goes here

You can use functions like test_common::assert_eq to assert equality between two Eigen matrices. The cumsum test is a good simple example of a test case.

Many libigl functions act on triangle meshes, you can use igl::read_triangle_mesh(test_common::data_path("cube.obj"), V, F) to load a triangle mesh located in the test data folder.


The data used for testing is not in the main libigl repository. Instead it is contained in the libigl-tests-data repository. It is automatically downloaded when LIBIGL_BUILD_TESTS is enabled.


When naming a test for a function igl::extra::function_name use:

TEST_CASE("function_name: my_description", "[igl/extra]")

where my_description can be used to identify the type of unit test being run on the function function_name.


The test for igl::copyleft::cgal::order_facets_around_edges in include/igl/copyleft/cgal/order_facets_around_edges.cpp is:

TEST_CASE("copyleft_cgal_order_facets_around_edges: Simple", "[igl/copyleft/cgal]")

which tests this function on example data containing a triplet of faces.



(Obviously?) The presence of a unit test here for some function (e.g., igl::cotmatrix) is not a guarantee or even an endorsement of the notion that the libigl function igl::cotmatrix is bug free or “fully tested” or “heavily tested” or even “adequately tested”.

Need Work?

Some of the most used libigl functions

grep -hr "^#include \"" ../libigl/include/igl | sed -e 's/\(\.\.\/\)//g' | sort | uniq -c | sort

still don’t have unit tests.