Scruffy

Why not use gtest? Well I do on C++ code, but I also write a lot of C code and wanted somethig similar. This provides the majority of what I do for testing.

Grok helped me write these and I fine tuned and adjusted them to my liking

Output

Success

[==========] Starting tests
[----------] Global test environment set-up.
[ RUN      ] scruffy.floats
[       OK ] 2 / 2 tests passed (1 usec)
[----------]
[ RUN      ] scruffy.equals
[       OK ] 3 / 3 tests passed (1 usec)
[----------]
[ RUN      ] scruffy.bools
[       OK ] 5 / 5 tests passed (2 usec)
[----------]
[ RUN      ] scruffy.pointers
[       OK ] 7 / 7 tests passed (1 usec)
[----------]
[----------] Global test environment tear-down
[==========] 7 out of 7 total tests passed (28 usec total)

Failure

[==========] Starting tests
[----------] Global test environment set-up.
[ RUN      ] scruffy.floats

file: /Users/kevin/github/scruffy/examples/fail.c line: 7 
Expected a == 3.1f, got 3.120000 != 3.100000 (diff 0.020000 > 0.000010)

file: /Users/kevin/github/scruffy/examples/fail.c line: 10 
Expected b == 12.345, got 12.345670 != 12.345000 (diff 0.000670 > 0.000000)

[  FAILED  ] 0 / 2 tests passed (9 usec)
[----------]
[ RUN      ] scruffy.equals

file: /Users/kevin/github/scruffy/examples/fail.c line: 14 
Expected 1 == 2, got 1 != 2

[  FAILED  ] 0 / 3 tests passed (3 usec)
[----------]
[ RUN      ] scruffy.bools

file: /Users/kevin/github/scruffy/examples/fail.c line: 22 
Expected (test_true()) == false

file: /Users/kevin/github/scruffy/examples/fail.c line: 23 
Expected (1 == 2) == true

file: /Users/kevin/github/scruffy/examples/fail.c line: 24 
Expected (1 == 1) == false

[  FAILED  ] 1 / 7 tests passed (4 usec)
[----------]
[ RUN      ] scruffy.pointers

file: /Users/kevin/github/scruffy/examples/fail.c line: 29 
Expected (p) == NULL

file: /Users/kevin/github/scruffy/examples/fail.c line: 33 
Expected (p) != NULL

[  FAILED  ] 1 / 9 tests passed (6 usec)
[----------]
[----------] Global test environment tear-down
[==========] 8 out of 9 total tests failed (40 usec total)

Tests

• EXPECT_NULL(pointer): pass if ptr == NULL
• EXPECT_NOT_NULL(pointer): pass if ptr != NULL
• EXPECT_TRUE(condition): pass if condition is true
• EXPECT_FALSE(condition): pass if condition is false
• EXPECT_EQ(int, int): pass if int == int
• EXPECT_FLOAT_EQ(float, float): pass if float == float
• EXPECT_DOUBLE_EQ(double, double): pass if double == double
• TEST(suite, test): creates a test function named void suite_test(void) and registers the function
• RUN_ALL(): runs all test functions and prints results

Each macro is wrapped in a do {...} while(0) loop to avoid problems.

• Ensures EXPECT_ acts like single statement
• Avoids dangling else problems (see below)
• Ensures proper scope for temporary variables in the testing framework
• Properly consumes the semicolon at the end of EXPECT_ statements
• No performance overhead, since compilers will optimize it away

Limitations

• You can only write 300 TEST() functions in your code.

Dangling else Problem

if (some_condition)
    EXPECT_TRUE(x == y);
else
    printf("Condition false\n");

After macro expansion:

if (some_condition)
    test_count++;
    if (!(x == y)) {
        TEST_FAIL_MESSAGE("Expected x == y to be true", "x == y");
    };
else
    printf("Condition false\n");

The else now gets associated with the second if, which is not what was planned.

While the do {...} while(0) is correct.

if (some_condition)
    do {
        test_count++;
        if (!(x == y)) {
            TEST_FAIL_MESSAGE("Expected x == y to be true", "x == y");
        }
    } while (0);
else
    printf("Condition false\n");

Examples

See examples folder, but here is a simple example:

TEST(scruffy, pointers) {
  EXPECT_TRUE(1 == 1);
  EXPECT_FALSE(1 == 2);

  int *p = NULL;
  EXPECT_NULL(p);

  int a = 3;
  p = &a;
  EXPECT_NOT_NULL(p);
}

RUN_ALL();

MIT License

Copyright (c) 2025 Mom's Friendly Robot Company

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.