Awesome

Sweet

A hierarchical test suite for C.

"Test suite... 'Sweet'... ha. ha."

Setup

Download sweet.h into your project folder, then simply #include "sweet.h" into the compilation unit[1] to test.

[1]: If you're not sure what this means, you can roughly substitute 'file'.

Usage

Typical usage:

// Test types
Test(expr);          // passes if expr evaluates non-zero
TestEq(a, b);        // - compares a and b byte-by-byte
                     // - no type checking except sizeof a vs b
                     // - only works with addressable values
TestVEq(a, b);       // does a simple value equal (must be a primitive type)
TestOp(a, op, b);    // tests a against b with op. e.g. a >= b

// Grouping
TestGroup("Description of test group")
{ // braces are just for clarity
    // ... tests
    TestGroup("Subgroup of tests")
    {
        // ... more tests
        // etc
    } EndTestGroup;
} EndTestGroup;

// ... other stuff

// Printing
int NumberOfFailedTests = PrintTestResults();

Group fail/pass:

Groups only pass if all their children pass. Skipped children are completely ignored.

Skipping:

Prepend tests or groups of tests with Skip to skip them and any subtests. This keeps the test around and reminds you that it exists, but doesn't affect the results.

Unit tests:

Super simple. If your project (the thing to be tested) is project.c:

// test_project.c
#include 'sweet.h'
#include 'project.c'
int main() {
    // tests on project.c as above
    return PrintTestResults();
}
SWEET_END_TESTS;

Because PrintTestResults returns 0 on all (non-skipped) tests passing and >0 otherwise, it can be used as the return status from main.

This means you can determine if your test suite is passing from the command line. You can then use this e.g. in a Git pre-commit hook, preventing the commit if tests fail.

Within-project testing:

I'm not sure this is currently recommended, but there's no particular reason this shouldn't work, bearing in mind the limitations below.

Compile-time options

Copy, paste and alter the following #defines wherever necessary. The defaults are shown here.

// File to print to
#define SWEET_OUTFILE stdout

// Assumes used in 1 compilation unit, change to blank/`extern` if desired
#define SWEET_STATIC static

// Define as blank if `inline` is not supported by your compiler
#define SWEET_INLINE inline


// This is not defined by default. Define as below to remove the ANSI colour escape codes.
#define SWEET_NOCOLOUR

Advanced use:

See sweet.c and sweet2.c.

You can redefine Assert as Test to see the result of all assumptions, rather than just breaking at the first that's incorrect.

If you're using Windows and want cmd to show colours, an easy way is to use ansicon. Just download it and install it with cmd i.e. x64\ansicon.exe -i, then you're ready to go!

Things to look out for: Calling a function with groups of tests while already in the middle of a group of tests will normally flatten the nenw hierarchy. Hint: use NewTestGroup(m)... EndNewTestGroup; as the base group in called functions.

Limitations

sweet.h currently uses __COUNTER__ to keep track of the array of tests. This may not play nicely if your project uses __COUNTER__ elsewhere...

For the same reason, the tests will be printed in the order that they appear in the compilation unit.

Tests that aren't hit at runtime can't have any information printed about them other than that they were not hit. This includes which file they're in, so they may be guessed to be in the file before if there are no tests hit in between. (If you have any way around this I'd be happy to hear it).

Because TestEq does a byte-by-byte comparison of the 2 variables passed to it, it's only a shallow comparison. i.e. if your structs contain a pointer, this will only check that the addresses of the pointers are equal, not whether what is pointed to by them is equal.

Additionally, it's possible to be caught out by tagged unions - if you're currently using the smaller of multiple variables in a union and there are stale bytes in the larger variable, these may be different between compared unions. As a result, the test will fail even though what you care about should pass.