Unit Testing

libs/unittest provides a very primitive unit testing framework for libraries (in libs) and userspace applications (in servers). It's useful if you're writing a somewhat complicated function.

This framework enables some attractive characteristics and features:

  • The framework compiles tests into a normal userspace application for the your development environment (e.g. macOS).
  • Since the testing program is a native application, it is super-fast and you can use your favorite debugging tools like LLDB!
  • Undefined Behavior Sanitizer and Address Santizer are enabled by default.


  • You can't use system calls (e.g. message passing) from the testing environment.
  • main() in your Resea application won't be called.

Writing Tests

#include <unittest.h>

int add(int a, int b) {
    return a + b;

TEST("1 + 1 equals to 2") {
    TEST_EXPECT_EQ(add(1, 1), 2);


  • TEST("description"): Use this macro to define a unit testing function.
  • TEST_EXPECT_EQ(a, b): Checks if a == b holds.
  • TEST_EXPECT_NE(a, b): Checks if a != b holds.
  • TEST_EXPECT_LT(a, b): Checks if a < b holds.
  • TEST_EXPECT_LE(a, b): Checks if a <= b holds.
  • TEST_EXPECT_GT(a, b): Checks if a > b holds.
  • TEST_EXPECT_GE(a, b): Checks if a >= b holds.

How to Run Tests

$ make unittest TARGET=servers/apps/test