A very simple, small, single-header, unit test framework for C (and C ).
(Join us on our Discord channel for queries and feedback)

tst is a lightweight unit testing framework designed for C programs (but works for C as well). It provides a suite of functionalities to define, group, and validate test cases, while offering utilities for expressive reporting and diagnostic messaging. With minimal syntax, tst fosters easy test integration into C projects.

I never understood why some of the most common unit test frameworks had so many files and complex build dependencies so I decided to write a small (less than 300 lines of code), no-dependencies unit testing framework that still has most of the feautures you can find in much more complex ones.

If you want to use tst, just include tst.h and you're ready to write your test cases.

Check the tutorial for a detailed description of how to use tst or the reference manual for a short description of each function.

Fell free to provide ideas, bugs, suggestions or even full Pull Requests if you feel inclined to do so!

tst.h has been tested and confirmed to work on the following combination of platforms/compilers. If you find any issue on using tst.h with your compiler, please let me know.

• gcc On Linux and Windows WSL2
• g On Linux and Windows WSL2
• clang On Linux and Windows WSL2
• cl (C) On Windows (see the test-cl directory)
• cl (C ) On Windows (see the test-cl directory)
• mingw-gcc On Windows

#include "tst.h"  // Ensure the tst framework is included

tstsuite("Primary Test Suite")
{    
    tstcase("Equality Checks %d, %d", 1, 1) {
      tstcheck(1 == 1, "Mismatch: %d != %d", 1, 1);
      tstcheck(1 != 1, "Failed on purpose");
    }
    
    tstclock("Check counting time") {
      volatile int b = 1;
      // Code to analyze...
      for (int a = 1; a < 100 ; a  ) b = a   b;
    }
    
    tstcase("Edge Cases") {
      tstskipif(1 == 1) {  // Next tests will be skipped!
        tstcheck(0 < 1, "0 should be less than 1");
        tstassert(1 >= 1, "1 should be equal to 1");
      }

      tstskipif(1 != 2) {  // Next tests will be executed!
        tstcheck(0 < 1, "0 should be less than 1");
        tstassert(1 >= 1, "1 should be equal to 1");
      }
    }
    
    tstnote("Testing Complete. Review for any FAIL flags.");
}

Compile and run the above program (no need for a main() function) to execute all the tests and generate a log like this:

----- SUIT ▷ t_small_example.c "Primary Test Suite"
    5 CASE┬── Equality Checks 1, 1
    6 PASS│  1 == 1
    7 FAIL├┬ 1 != 1
          │╰ Failed on purpose
    5     ╰── 1 KO | 1 OK | 0 SKIP
   10 CLCK⚑  1 µs Check counting time
   16 CASE┬── Edge Cases
   17 NOTE: SKIP condition: `1 == 1`
   18 SKIP│  0 < 1
   19 SKIP│  1 >= 1
   22 NOTE: SKIP condition: `1 != 2`
   23 SKIP│  0 < 1
   24 SKIP│  1 >= 1
   16     ╰── 0 KO | 0 OK | 4 SKIP
   28 NOTE: Testing Complete. Review for any FAIL flags.
^^^^^ RSLT ▷ 1 KO | 1 OK | 4 SKIP

There is no limitation on how you organize and run your tests. Just for the purpose of self-testing (and to provide an example on how you could organize your testing workflow) the makefile and the tstrun script in the test directory provide a convenient way to launch groups of tests and pass them arguments.