FLAT provides a built-in test framework. It is especially useful to unit-test templates, error handling and upstream requests.


FLAT tests are defined as flow files with the root node flat-test. There are a couple of specialized test actions that accompany the test flow. The invocation of at least one assert action is mandatory.

<!-- flow code -->
[ … ]


Test files can be stored anywhere inside the FLAT app directory. We recommend creating a tests/ folder next to swagger.yaml.


FLAT tests are started with the flat cli command test:

$ flat test tests/test-foo.xml tests/test-bar.xml

The test result is printed in TAP format:

ok 1 tests/test-foo.xml: 17 assertions
ok 2 tests/test-bar.xml: 4 assertions
passed: 2, failed: 0

If all tests pass, the exit code is 0. If any test fails, the code is non-zero (1). Therefore, in deployment scripts or Makefile recipes (both of which are usually executed as set -e) you can rely on the exit code to fail the process.

See also