diff --git a/CMakeLists.txt b/CMakeLists.txt
new file mode 100644
index 0000000..1a769ac
--- /dev/null
+++ b/CMakeLists.txt
@@ -0,0 +1,21 @@
+cmake_minimum_required(VERSION 3.21)
+project(xtest C)
+
+set(CMAKE_C_STANDARD 11)
+set(CMAKE_C_STANDARD_REQUIRED TRUE)
+
+set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -Wall -Werror -pedantic")
+
+add_compile_definitions(XTEST)
+
+
+add_executable(example-all xtest.c examples/all.c examples/parameterized.c examples/assertions.c examples/expect_assertions.c examples/fail.c examples/groups.c examples/float.c examples/source.c examples/source.h examples/skip.c)
+target_compile_definitions(example-all PRIVATE XTEST_ALL_EXAMPLES)
+
+add_executable(example-assertions xtest.c examples/assertions.c examples/source.c examples/source.h)
+add_executable(example-expect_assertions xtest.c examples/expect_assertions.c examples/source.c examples/source.h)
+add_executable(example-fail xtest.c examples/fail.c examples/source.c examples/source.h)
+add_executable(example-float xtest.c examples/float.c examples/source.c examples/source.h)
+add_executable(example-groups xtest.c examples/groups.c examples/source.c examples/source.h)
+add_executable(example-parameterized xtest.c examples/parameterized.c examples/source.c examples/source.h)
+add_executable(example-skip xtest.c examples/skip.c examples/source.c examples/source.h)
diff --git a/examples/all.c b/examples/all.c
new file mode 100644
index 0000000..9d77b1a
--- /dev/null
+++ b/examples/all.c
@@ -0,0 +1,22 @@
+#include "../xtest.h"
+
+
+void example_assertions();
+void example_expect_assertions();
+void example_fail();
+void example_float();
+void example_groups();
+void example_parameterized();
+void example_skip();
+
+
+int main(int argc, char ** argv) {
+    xtest_run_group(example_assertions);
+    xtest_run_group(example_expect_assertions);
+    xtest_run_group(example_fail);
+    xtest_run_group(example_float);
+    xtest_run_group(example_groups);
+    xtest_run_group(example_parameterized);
+    xtest_run_group(example_skip);
+    return xtest_complete();
+}
\ No newline at end of file
diff --git a/examples/assertions.c b/examples/assertions.c
new file mode 100644
index 0000000..0cc5c9b
--- /dev/null
+++ b/examples/assertions.c
@@ -0,0 +1,106 @@
+#include <stddef.h>
+#include "../xtest.h"
+#include "source.h"
+
+void test_assert(void *fixture, void **params) {
+    int i1 = 1;
+    int i2 = 1;
+    int i3 = 2;
+    double d1 = 1.0;
+    double d2 = 1.0;
+    double d3 = 2.0;
+    char c1 = 'a';
+    char c2 = 'a';
+    char c3 = 'b';
+    unsigned int u1 = 1;
+    unsigned int u2 = 1;
+    unsigned int u3 = 2;
+
+    xtest_assert(i1 == i2);
+    xtest_assert(i1 != i3);
+
+    xtest_assert(d1 == d2);
+    xtest_assert(d1 != d3);
+
+    xtest_assert(c1 == c2);
+    xtest_assert(c1 != c3);
+
+    xtest_assert(u1 == u2);
+    xtest_assert(u1 != u3);
+
+    xtest_assert(1);
+    xtest_assert(ret_1());
+}
+
+void test_assert_is(void *fixture, void **params) {
+    int i1 = 1;
+    int i2 = 1;
+    int i3 = 2;
+    double d1 = 1.0;
+    double d2 = 1.0;
+    double d3 = 2.0;
+    char c1 = 'a';
+    char c2 = 'a';
+    char c3 = 'b';
+    unsigned int u1 = 1;
+    unsigned int u2 = 1;
+    unsigned int u3 = 2;
+
+    _Bool b1 = 0;
+    _Bool b2 = 0;
+    _Bool b3 = 1;
+
+    xtest_assert_is(i1, i2);
+    xtest_assert_is_not(i1, i3);
+
+    xtest_assert_float_is(d1, d2, 4);
+    xtest_assert_float_is_not(d1, d3, 4);
+
+    xtest_assert_is(c1, c2);
+    xtest_assert_is_not(c1, c3);
+
+    xtest_assert_is(u1, u2);
+    xtest_assert_is_not(u1, u3);
+
+    xtest_assert_is(b1, b2);
+    xtest_assert_is_not(b1, b3);
+}
+
+void test_assert_str_is(void *fixture, void **params) {
+    const char *s1 = "ret_1";
+    const char *s2 = "ret_1";
+    const char *s3 = "bar";
+
+    xtest_assert_str_is(s1, s2);
+    xtest_assert_str_is_not(s1, s3);
+}
+
+void test_assert_mem_is(void *fixture, void **params) {
+    char m1[100];
+    char m2[100];
+    for (int i = 0; i < 100; ++i) {
+        m1[i] = m2[i] = 'a';
+    }
+    for (int i = 50; i < 100; ++i) {
+        m2[i] = 'b';
+    }
+
+    xtest_assert_mem_is(m1, m2, 10);
+    xtest_assert_mem_is(m1, m2, 50);
+    xtest_assert_mem_is_not(m1, m2, 60);
+    xtest_assert_mem_is_not(m1, m2, 100);
+}
+
+void example_assertions() {
+    xtest_run(test_assert);
+    xtest_run(test_assert_is);
+    xtest_run(test_assert_str_is);
+    xtest_run(test_assert_mem_is);
+}
+
+#ifndef XTEST_ALL_EXAMPLES
+int main(int argc, char **argv) {
+    example_assertions();
+    return xtest_complete();
+}
+#endif
\ No newline at end of file
diff --git a/examples/expect_assertions.c b/examples/expect_assertions.c
new file mode 100644
index 0000000..d435018
--- /dev/null
+++ b/examples/expect_assertions.c
@@ -0,0 +1,46 @@
+#include "../xtest.h"
+#include "source.h"
+
+void test_simple() {
+    xtest_expect_assertion_failure();
+    div(10, 0);
+}
+
+void test_no_failure() {
+    div(10,1);
+}
+
+void test_no_failure_2() {
+    div(10,2);
+}
+
+void test_will_fail() {
+    xtest_expect_assertion_failure();
+    div(10,1);
+}
+
+void test_will_fail_2() {
+    div(10,0);
+}
+
+void test_other_failure() {
+    xtest_expect_assertion_failure();
+    xtest_assert(0);
+    div(10, 0);
+}
+
+void example_expect_assertions() {
+    xtest_run(test_simple);
+    xtest_run(test_no_failure);
+    xtest_run(test_other_failure);
+    xtest_run(test_will_fail);
+    xtest_run(test_will_fail_2);
+    xtest_run(test_no_failure_2);
+}
+
+#ifndef XTEST_ALL_EXAMPLES
+int main(int argc, char **argv) {
+    example_expect_assertions();
+    return xtest_complete();
+}
+#endif
\ No newline at end of file
diff --git a/examples/fail.c b/examples/fail.c
new file mode 100644
index 0000000..5d70c02
--- /dev/null
+++ b/examples/fail.c
@@ -0,0 +1,188 @@
+#include <stddef.h>
+#include "../xtest.h"
+
+void fail_assert() {
+    xtest_assert(0);
+}
+
+void fail_assert_is_char() {
+    xtest_assert_is((char)'a', (char)'b');
+}
+
+void fail_assert_is_not_char() {
+    xtest_assert_is_not((char)'a', (char)'a');
+}
+
+void fail_assert_is_signed_char() {
+    xtest_assert_is((signed char)'a', (signed char)'b');
+}
+
+void fail_assert_is_not_signed_char() {
+    xtest_assert_is_not((signed char)'a', (signed char)'a');
+}
+
+void fail_assert_is_unsigned_char() {
+    xtest_assert_is((unsigned char)'a', (unsigned char)'b');
+}
+
+void fail_assert_is_not_unsigned_char() {
+    xtest_assert_is_not((unsigned char)'a', (unsigned char)'a');
+}
+
+void fail_assert_is_short() {
+    xtest_assert_is((short) 1, (short) 2);
+}
+
+void fail_assert_is_not_short() {
+    xtest_assert_is_not((short) 1, (short) 1);
+}
+
+void fail_assert_is_ushort() {
+    xtest_assert_is((unsigned short) 1, (unsigned short) 2);
+}
+
+void fail_assert_is_not_ushort() {
+    xtest_assert_is_not((unsigned short) 1, (unsigned short) 1);
+}
+
+void fail_assert_is_int() {
+    xtest_assert_is((int) 1, (int) 2);
+}
+
+void fail_assert_is_not_int() {
+    xtest_assert_is_not((int) 1, (int) 1);
+}
+
+void fail_assert_is_uint() {
+    xtest_assert_is((unsigned int) 1, (unsigned int) 2);
+}
+
+void fail_assert_is_not_uint() {
+    xtest_assert_is_not((unsigned int) 1, (unsigned int) 1);
+}
+
+void fail_assert_is_long() {
+    xtest_assert_is((short) 1, (short) 2);
+}
+
+void fail_assert_is_not_long() {
+    xtest_assert_is_not((long) 1, (long) 1);
+}
+
+void fail_assert_is_ulong() {
+    xtest_assert_is((unsigned long) 1, (unsigned long) 2);
+}
+
+void fail_assert_is_not_ulong() {
+    xtest_assert_is_not((unsigned long) 1, (unsigned long) 1);
+}
+
+void fail_assert_is_longlong() {
+    xtest_assert_is((long long) 1, (long long) 2);
+}
+
+void fail_assert_is_not_longlong() {
+    xtest_assert_is_not((long long) 1, (long long) 1);
+}
+
+void fail_assert_is_ulonglong() {
+    xtest_assert_is((unsigned long long) 1, (unsigned long long) 2);
+}
+
+void fail_assert_is_not_ulonglong() {
+    xtest_assert_is_not((unsigned long long) 1, (unsigned long long) 1);
+}
+
+void fail_assert_is_ptr() {
+    int i = 1;
+    int j = 1;
+    xtest_assert_is((void*) &i, (void*) &j);
+}
+
+void fail_assert_is_not_ptr() {
+    int i = 1;
+    xtest_assert_is_not((void*) &i, (void*) &i);
+}
+
+void fail_assert_str_is() {
+    xtest_assert_str_is("foo", "bar");
+}
+
+void fail_assert_str_is_not() {
+    xtest_assert_str_is_not("foo", "foo");
+}
+
+void fail_assert_mem_is() {
+    xtest_assert_mem_is("aaaaaaaaaaaaa", "aaaaaaaaaaaab", 13);
+}
+
+void fail_assert_mem_is_not() {
+    xtest_assert_mem_is_not("aaaaaaaaaaaaa", "aaaaaaaaaaaab", 12);
+}
+
+
+void fail_assert_float_is() {
+    xtest_assert_float_is(1.2356, 1.2346, 3);
+}
+
+
+void fail_assert_float_is_not() {
+    xtest_assert_float_is_not(1.2356, 1.2346, 2);
+}
+
+void fail_assert_is() {
+    xtest_run(fail_assert_is_char);
+    xtest_run(fail_assert_is_not_char);
+    xtest_run(fail_assert_is_signed_char);
+    xtest_run(fail_assert_is_not_signed_char);
+    xtest_run(fail_assert_is_unsigned_char);
+    xtest_run(fail_assert_is_not_unsigned_char);
+    xtest_run(fail_assert_is_short);
+    xtest_run(fail_assert_is_not_short);
+    xtest_run(fail_assert_is_ushort);
+    xtest_run(fail_assert_is_not_ushort);
+    xtest_run(fail_assert_is_int);
+    xtest_run(fail_assert_is_not_int);
+    xtest_run(fail_assert_is_uint);
+    xtest_run(fail_assert_is_not_uint);
+    xtest_run(fail_assert_is_long);
+    xtest_run(fail_assert_is_not_long);
+    xtest_run(fail_assert_is_ulong);
+    xtest_run(fail_assert_is_not_ulong);
+    xtest_run(fail_assert_is_longlong);
+    xtest_run(fail_assert_is_not_longlong);
+    xtest_run(fail_assert_is_ulonglong);
+    xtest_run(fail_assert_is_not_ulonglong);
+    xtest_run(fail_assert_is_ptr);
+    xtest_run(fail_assert_is_not_ptr);
+}
+
+void fail_assert_str() {
+    xtest_run(fail_assert_str_is);
+    xtest_run(fail_assert_str_is_not);
+}
+
+void fail_assert_mem() {
+    xtest_run(fail_assert_mem_is);
+    xtest_run(fail_assert_mem_is_not);
+}
+
+void fail_assert_float() {
+    xtest_run(fail_assert_float_is);
+    xtest_run(fail_assert_float_is_not);
+}
+
+void example_fail() {
+    xtest_run(fail_assert);
+    xtest_run_group(fail_assert_is);
+    xtest_run_group(fail_assert_str);
+    xtest_run_group(fail_assert_mem);
+    xtest_run_group(fail_assert_float);
+}
+
+#ifndef XTEST_ALL_EXAMPLES
+int main(int argc, char **argv) {
+    example_fail();
+    return xtest_complete();
+}
+#endif
\ No newline at end of file
diff --git a/examples/float.c b/examples/float.c
new file mode 100644
index 0000000..9548c05
--- /dev/null
+++ b/examples/float.c
@@ -0,0 +1,46 @@
+#include <stddef.h>
+#include "../xtest.h"
+
+void test_float() {
+    xtest_assert_float_is(1.0, 1.0, 0);
+    xtest_assert_float_is(1.0, 1.0, 1);
+    xtest_assert_float_is(1.0, 1.0, 2);
+    xtest_assert_float_is(1.0, 1.0, 3);
+    xtest_assert_float_is(1.0, 1.0, 4);
+    xtest_assert_float_is(1.0, 1.0, 5);
+    xtest_assert_float_is_not(1.0, 2.0, 0);
+    xtest_assert_float_is_not(1.0, 2.0, 1);
+    xtest_assert_float_is_not(1.0, 2.0, 2);
+    xtest_assert_float_is_not(1.0, 2.0, 3);
+    xtest_assert_float_is_not(1.0, 2.0, 4);
+    xtest_assert_float_is_not(1.0, 2.0, 5);
+
+    xtest_assert_float_is(0.001, 0.00100000000001, 0);
+    xtest_assert_float_is(0.001, 0.00100000000001, 1);
+    xtest_assert_float_is(0.001, 0.00100000000001, 2);
+    xtest_assert_float_is(0.001, 0.00100000000001, 3);
+    xtest_assert_float_is(0.001, 0.00100000000001, 4);
+    xtest_assert_float_is(0.001, 0.00100000000001, 5);
+    xtest_assert_float_is(0.001, 0.00100000000001, 6);
+    xtest_assert_float_is(0.001, 0.00100000000001, 7);
+    xtest_assert_float_is(0.001, 0.00100000000001, 8);
+    xtest_assert_float_is(0.001, 0.00100000000001, 9);
+    xtest_assert_float_is(0.001, 0.00100000000001, 10);
+    xtest_assert_float_is(0.001, 0.00100000000001, 11);
+    xtest_assert_float_is(0.001, 0.00100000000001, 12);
+    xtest_assert_float_is(0.001, 0.00100000000001, 13);
+    xtest_assert_float_is_not(0.001, 0.00100000000001, 14);
+    xtest_assert_float_is_not(0.001, 0.00100000000001, 15);
+    xtest_assert_float_is_not(0.001, 0.00100000000001, 16);
+}
+
+void example_float() {
+    xtest_run(test_float);
+}
+
+#ifndef XTEST_ALL_EXAMPLES
+int main(int argc, char **argv) {
+    example_float();
+    return xtest_complete();
+}
+#endif
\ No newline at end of file
diff --git a/examples/groups.c b/examples/groups.c
new file mode 100644
index 0000000..b965ee3
--- /dev/null
+++ b/examples/groups.c
@@ -0,0 +1,103 @@
+#include <stddef.h>
+#include "../xtest.h"
+
+void test_1() {}
+void test_2() {}
+void test_3() {}
+void test_4() {}
+void test_5() {}
+void test_6() {}
+void test_7() {}
+void test_8() {}
+void test_9() {}
+
+
+void groups_manual() {
+    xtest_group(A);
+    xtest_group(foo);
+    xtest_run(test_1);
+    xtest_group(bar);
+    xtest_run(test_2);
+    xtest_run(test_3);
+    xtest_end_group();
+    xtest_end_group();
+    xtest_run(test_4);
+    xtest_end_group();
+    xtest_group(B);
+    xtest_run(test_5);
+    xtest_run(test_6);
+    xtest_end_group();
+    xtest_group(C);
+    xtest_group(X);
+    xtest_group(Y);
+    xtest_group(Z);
+    xtest_run(test_7);
+    xtest_end_group();
+    xtest_end_group();
+    xtest_end_group();
+    xtest_end_group();
+    xtest_group(D);
+    xtest_run(test_8);
+    xtest_run(test_9);
+    xtest_end_group();
+}
+
+void bar() {
+    xtest_run(test_2);
+    xtest_run(test_3);
+}
+
+void foo() {
+    xtest_run(test_1);
+    xtest_run_group(bar);
+}
+
+void A() {
+    xtest_run_group(foo);
+    xtest_run(test_4);
+}
+
+void B() {
+    xtest_run(test_5);
+    xtest_run(test_6);
+}
+
+void Z() {
+    xtest_run(test_7);
+}
+
+void Y() {
+    xtest_run_group(Z);
+}
+
+void X() {
+    xtest_run_group(Y);
+}
+
+void C() {
+    xtest_run_group(X);
+}
+
+void D() {
+    xtest_run(test_8);
+    xtest_run(test_9);
+}
+
+void groups_convenient() {
+    xtest_run_group(A);
+    xtest_run_group(B);
+    xtest_run_group(C);
+    xtest_run_group(D);
+}
+
+void example_groups() {
+    groups_manual();
+    groups_convenient();
+}
+
+#ifndef XTEST_ALL_EXAMPLES
+int main(int argc, char **argv) {
+    example_groups();
+    return xtest_complete();
+}
+#endif
\ No newline at end of file
diff --git a/examples/parameterized.c b/examples/parameterized.c
new file mode 100644
index 0000000..7289bde
--- /dev/null
+++ b/examples/parameterized.c
@@ -0,0 +1,86 @@
+#include <stddef.h>
+#include "../xtest.h"
+#include "source.h"
+
+void test_add(void *fixture, void **params) {
+    int a = xtest_get_param(int, 0, params);
+    int b = xtest_get_param(int, 1, params);
+    int result = a + b;
+    xtest_assert_is(add(a, b), result);
+}
+
+void test_str_equals(void *fixture, void **params) {
+    const char* s1 = xtest_get_param_ptr(const char*, 0, params);
+    const char* s2 = xtest_get_param_ptr(const char*, 1, params);
+    if (str_equals(s1, s2)) {
+        xtest_assert_str_is(s1, s2);
+    } else {
+        xtest_assert_str_is_not(s1, s2);
+    }
+}
+
+
+
+xtest_param add_params[] = {
+    {
+        .name = "A",
+        .values = &(xtest_param_values) {
+            &(int) {1},
+            &(int) {10},
+            &(int) {100},
+            NULL
+        }
+    },
+    {
+        .name = "B",
+        .values = &(xtest_param_values) {
+            &(int) {2},
+            &(int) {22},
+            &(int) {222},
+            NULL
+        }
+    },
+    {
+        .name = NULL,
+        .values = NULL,
+    }
+};
+
+
+xtest_param str_params[] = {
+    {
+        .name = "A",
+        .values = &(xtest_param_values) {
+            "foo",
+            "bar",
+            "hello",
+            "world",
+            NULL
+        }
+    },
+    {
+        .name = "B",
+        .values = &(xtest_param_values) {
+            "foo",
+            "bar",
+            "xyz",
+            NULL
+        }
+    },
+    {
+        .name = NULL,
+        .values = NULL,
+    }
+};
+
+void example_parameterized() {
+    xtest_run_parameterized(test_add, add_params);
+    xtest_run_parameterized(test_str_equals, str_params);
+}
+
+#ifndef XTEST_ALL_EXAMPLES
+int main(int argc, char **argv) {
+    example_parameterized();
+    return xtest_complete();
+}
+#endif
\ No newline at end of file
diff --git a/examples/skip.c b/examples/skip.c
new file mode 100644
index 0000000..489f1ca
--- /dev/null
+++ b/examples/skip.c
@@ -0,0 +1,61 @@
+
+#include "../xtest.h"
+#include "source.h"
+
+void no_skip_1() {}
+
+void no_skip_2() {}
+
+void no_skip_3() {}
+
+void no_skip_4() {}
+
+void no_skip_5() {}
+
+void no_skip_6() {}
+
+void skip_1() {
+    xtest_skip("foo");
+}
+
+void skip_2() {
+    xtest_skip("bar");
+}
+
+void skip_3() {
+    xtest_skip(NULL);
+}
+
+void skip_4() {
+    xtest_skip("some reason");
+}
+
+void skip_5() {
+    xtest_skip("other reason");
+}
+
+void skip_6() {
+    xtest_skip(NULL);
+}
+
+void example_skip() {
+    xtest_run(no_skip_1);
+    xtest_run(skip_1);
+    xtest_run(no_skip_2);
+    xtest_run(no_skip_3);
+    xtest_run(skip_2);
+    xtest_run(skip_3);
+    xtest_run(skip_4);
+    xtest_run(no_skip_4);
+    xtest_run(skip_5);
+    xtest_run(no_skip_5);
+    xtest_run(no_skip_6);
+    xtest_run(skip_6);
+}
+
+#ifndef XTEST_ALL_EXAMPLES
+int main(int argc, char **argv) {
+    example_skip();
+    return xtest_complete();
+}
+#endif
\ No newline at end of file
diff --git a/examples/source.c b/examples/source.c
new file mode 100644
index 0000000..7df04f9
--- /dev/null
+++ b/examples/source.c
@@ -0,0 +1,22 @@
+#include <string.h>
+#include "source.h"
+#include "../xassert.h"
+
+int ret_1() {
+    return 1;
+}
+
+double div(double a, double b) {
+    assert(b != 0.0);
+    return a/b;
+}
+
+
+int add(int a, int b) {
+    return a + b;
+}
+
+int str_equals(const char *s1, const char *s2) {
+    return strcmp(s1, s2) == 0;
+}
+
diff --git a/examples/source.h b/examples/source.h
new file mode 100644
index 0000000..2c23264
--- /dev/null
+++ b/examples/source.h
@@ -0,0 +1,13 @@
+#ifndef XTEST_SOURCE_H
+#define XTEST_SOURCE_H
+
+int ret_1();
+
+double div(double a, double b);
+
+
+int add(int a, int b);
+
+int str_equals(const char * s1, const char * s2);
+
+#endif //XTEST_SOURCE_H
diff --git a/xassert.h b/xassert.h
new file mode 100644
index 0000000..6ce5193
--- /dev/null
+++ b/xassert.h
@@ -0,0 +1,18 @@
+#include <assert.h>
+
+#define XTEST_XASSERT
+
+#if defined(XTEST_XTEST_H)  && !defined(XTEST_SOURCE)
+#error "do not include xtest.h and xassert.h at the same time. xassert.h should only be included from your source files and xtest.h should only be included from your test files."
+#endif
+
+#if defined(XTEST) && (!defined(XTEST_XTEST_H) || defined(XTEST_SOURCE))
+
+void xtest_internal_assert(const char* file, int line, const char* func, const char* expr);
+
+#undef assert
+
+#define assert(__e) ((__e) ? (void)0 : xtest_internal_assert(__FILE__, __LINE__, \
+						       __ASSERT_FUNC, #__e))
+
+#endif //defined(XTEST) && !defined(XTEST_XTEST_H)
diff --git a/xtest.c b/xtest.c
new file mode 100644
index 0000000..92842be
--- /dev/null
+++ b/xtest.c
@@ -0,0 +1,312 @@
+#include <setjmp.h>
+#include <math.h>
+
+#define XTEST_SOURCE
+
+#include "xtest.h"
+#include "xassert.h"
+
+struct xtest_assert_info {
+    const char *file;
+    int line;
+    const char *func;
+    const char *expr;
+};
+
+struct xtest_assert_info assertion_info;
+
+
+#ifndef XTEST_MAX_GROUP_NESTING
+#define XTEST_MAX_GROUP_NESTING 16
+#endif
+
+#ifndef XTEST_TEST_NAME_MAX_LENGTH
+#define XTEST_TEST_NAME_MAX_LENGTH 1023
+#endif
+
+const char * group_nesting[XTEST_MAX_GROUP_NESTING];
+int group_nesting_pos = 0;
+
+jmp_buf xtest_jmp;
+
+#ifndef XTEST_ASSERT_MESSAGE_MAX_LEN
+#define XTEST_ASSERT_MESSAGE_MAX_LEN 1023
+#endif
+char assert_message[XTEST_ASSERT_MESSAGE_MAX_LEN + 1];
+const char *skip_reason;
+
+int xtest_indent = 0;
+
+
+
+
+int expecting_assertion = 0;
+int num_tests = 0;
+int successful_tests = 0;
+int failed_tests = 0;
+int skipped_tests = 0;
+
+
+int xtest_complete() {
+#ifndef XTEST_ENABLE_SUBUNIT
+    printf("============\nTotal: %d, Failed: %d, Skipped: %d\n", num_tests, failed_tests, skipped_tests);
+#endif //XTEST_ENABLE_SUBUNIT
+    fflush(stdout);
+    return failed_tests != 0 ? 1 : 0;
+}
+
+void subunit_message(const char * name, const char * message, const char * details) {
+    printf("%s: %s", message, name);
+    if (details == NULL) {
+        printf("\n");
+    } else {
+        printf(" [\n%s%s]\n", details, details[strlen(details)] != '\n' ? "\n" : "");
+    }
+}
+
+void xtest_internal_run(xtest_test_fn fn, const char *name, xtest_param *params, xtest_setup_fn setup,
+                        xtest_teardown_fn teardown) {
+    num_tests += 1;
+    expecting_assertion = 0;
+
+    char full_name[XTEST_TEST_NAME_MAX_LENGTH + 1] = "";
+    size_t name_len = 0;
+    for (int i = 0; i < group_nesting_pos; ++i) {
+        name_len += snprintf(full_name + name_len, XTEST_TEST_NAME_MAX_LENGTH - name_len, "%s/", group_nesting[i]);
+        assert(name_len <= XTEST_TEST_NAME_MAX_LENGTH);
+    }
+    name_len += snprintf(full_name + name_len, XTEST_TEST_NAME_MAX_LENGTH - name_len, "%s", name);
+    assert(name_len <= XTEST_TEST_NAME_MAX_LENGTH);
+
+    void *fixture = NULL;
+
+#ifndef XTEST_ENABLE_SUBUNIT
+    printf("%*s%s: ", xtest_indent, "", name);
+#else
+    subunit_message(full_name, "test", NULL);
+#endif //XTEST_ENABLE_SUBUNIT
+
+    if (setup != NULL) {
+        int jmpres = setjmp(xtest_jmp);
+        if (jmpres == 0) {
+            setup(&fixture);
+        } else if (jmpres == 3) {
+            goto skipped;
+        } else {
+            snprintf(assert_message, 1024, "assertion failure in setup function: %s in %s (%s:%d)", assertion_info.expr,
+                     assertion_info.func, assertion_info.file, assertion_info.line);
+            goto failed;
+        }
+    }
+
+    int jmpres = setjmp(xtest_jmp);
+    if (jmpres == 0) {
+        if (params == NULL) {
+            expecting_assertion = 0;
+            fn(fixture, NULL);
+        } else {
+            int num_params = 0;
+            while (params[num_params].name != NULL) num_params++;
+            int validx[num_params];
+            int valmax[num_params];
+            void *current_vals[num_params];
+            for (int i = 0; i < num_params; ++i) {
+                validx[i] = 0;
+                valmax[i] = 0;
+                while ((*params[i].values)[valmax[i]] != NULL) valmax[i]++;
+            }
+            while (1) {
+                for (int i = 0; i < num_params; ++i) {
+                    current_vals[i] = (*params[i].values)[validx[i]];
+                }
+                expecting_assertion = 0;
+                fn(fixture, current_vals);
+                int carry = 1;
+                for (int i = num_params - 1; i >= 0; --i) {
+                    validx[i] += 1;
+                    if (validx[i] >= valmax[i]) {
+                        validx[i] = 0;
+                    } else {
+                        carry = 0;
+                        break;
+                    }
+                }
+                if (carry == 1) break;
+            }
+        }
+
+        if (expecting_assertion) { // an assertion failure in the tested code was expected but didn't occur
+            snprintf(assert_message, 1024, "expected an assertion failure in the tested code");
+            goto failed;
+        } else {
+            goto success;
+        }
+    } else if (jmpres == 1) { // a testing assertion failed
+        goto failed;
+    } else if (jmpres == 2) { // an assertion in the tested code failed
+        if (expecting_assertion) {
+            goto success;
+        } else {
+            snprintf(assert_message, 1024, "unexpected assertion failure in tested code: %s in %s (%s:%d)",
+                     assertion_info.expr, assertion_info.func, assertion_info.file, assertion_info.line);
+            goto failed;
+        }
+    } else if (jmpres == 3) {
+        goto skipped;
+    }
+
+  success:
+#ifndef XTEST_ENABLE_SUBUNIT
+    printf("SUCCESS\n");
+#else
+    subunit_message(full_name, "success", NULL);
+#endif //XTEST_ENABLE_SUBUNIT
+    successful_tests += 1;
+    goto cleanup;
+  failed:
+#ifndef XTEST_ENABLE_SUBUNIT
+    printf("FAILED:\n%*s  %s\n", xtest_indent, "", assert_message);
+#else
+    subunit_message(full_name, "failure", assert_message);
+#endif //XTEST_ENABLE_SUBUNIT
+    failed_tests += 1;
+    goto cleanup;
+  skipped:
+    skipped_tests += 1;
+#ifndef XTEST_ENABLE_SUBUNIT
+    if (skip_reason != NULL) {
+        printf("SKIPPED: %s\n", skip_reason);
+    } else {
+        printf("SKIPPED\n");
+    }
+#else
+    subunit_message(full_name, "skipped", skip_reason);
+#endif //XTEST_ENABLE_SUBUNIT
+    goto cleanup;
+
+  cleanup:
+    if (teardown != NULL && fixture != NULL) {
+        teardown(fixture);
+    }
+}
+
+
+/// this function replaces the standard library assert and jumps back to the xtest_internal_run invocation that is running the test
+/// \param file file in which the assertion happened
+/// \param line line on which the assertion happened
+/// \param func function in which the assertion happened
+/// \param expr stringified expression of the assertion
+void xtest_internal_assert(const char *file, int line, const char *func, const char *expr) {
+    assertion_info = (struct xtest_assert_info) {
+        .file = file, .line = line, .func = func, .expr = expr
+    };
+    longjmp(xtest_jmp, 2);
+}
+
+
+#define FAIL_ASSERT_FORMAT_1 "assertion failed: %s, expected %s"
+#define FAIL_ASSERT_FORMAT_2 " but got "
+#define FAIL_ASSERT_FORMAT_3 " (%s:%d)"
+#define FAIL_ASSERT_FORMAT(fmt) FAIL_ASSERT_FORMAT_1 fmt FAIL_ASSERT_FORMAT_2 fmt FAIL_ASSERT_FORMAT_3
+#define CAST_PTR(type, ptr) *(type *)(ptr)
+#define PRINT_ASSERT_MESSAGE(fmt, type) snprintf(assert_message, XTEST_ASSERT_MESSAGE_MAX_LEN, FAIL_ASSERT_FORMAT(fmt), \
+expression, invert ? "not " : "", CAST_PTR(type, expected), CAST_PTR(type, actual), file, line)
+
+
+void xtest_fail_assert(const char *expression, const char *file, int line, void *expected,
+                       void *actual, int invert, enum xtest_type type) {
+    switch (type) {
+        case xtest_type_bool:
+            snprintf(assert_message, XTEST_ASSERT_MESSAGE_MAX_LEN, FAIL_ASSERT_FORMAT("%s"), expression, invert ? "not " : "",
+                     CAST_PTR(_Bool, expected) ? "true" : "false", CAST_PTR(_Bool, actual) ? "true" : "false", file,
+                     line);
+            break;
+        case xtest_type_char:
+            PRINT_ASSERT_MESSAGE("'%c'", char);
+            break;
+        case xtest_type_short:
+            PRINT_ASSERT_MESSAGE("%i", short);
+            break;
+        case xtest_type_unsigned_short:
+            PRINT_ASSERT_MESSAGE("%u", unsigned short);
+            break;
+        case xtest_type_int:
+            PRINT_ASSERT_MESSAGE("%i", int);
+            break;
+        case xtest_type_unsigned_int:
+            PRINT_ASSERT_MESSAGE("%u", unsigned int);
+            break;
+        case xtest_type_long:
+            PRINT_ASSERT_MESSAGE("%li", long);
+            break;
+        case xtest_type_unsigned_long:
+            PRINT_ASSERT_MESSAGE("%lu", unsigned long);
+            break;
+        case xtest_type_long_long:
+            PRINT_ASSERT_MESSAGE("%lli", long long);
+            break;
+        case xtest_type_unsigned_long_long:
+            PRINT_ASSERT_MESSAGE("%llu", unsigned long long);
+            break;
+        case xtest_type_float:
+            PRINT_ASSERT_MESSAGE("%f", float);
+            break;
+        case xtest_type_double:
+            PRINT_ASSERT_MESSAGE("%f", double);
+            break;
+        case xtest_type_long_double:
+            PRINT_ASSERT_MESSAGE("%Lf", long double);
+            break;
+        case xtest_type_string:
+            PRINT_ASSERT_MESSAGE("\"%s\"", char*);
+            break;
+        case xtest_type_void_pointer:
+            PRINT_ASSERT_MESSAGE("%p", void*);
+            break;
+        case xtest_type_other:
+        default:
+            snprintf(assert_message, XTEST_ASSERT_MESSAGE_MAX_LEN, FAIL_ASSERT_FORMAT("%s"), expression, invert ? "not " : "",
+                     "<value of unknown type>", "<value of unknown type>", file, line);
+            break;
+    }
+    longjmp(xtest_jmp, 1);
+}
+
+void
+xtest_assert_float(double expected, double actual, int precision, int invert, const char *expression, const char *file,
+                   int line) {
+
+    double epsilon = pow(10, -(precision));
+    double diff = fabs(expected - actual);
+    int equals = diff < epsilon;
+    int failed = invert == equals; // invert = true: fail if equals, invert = false: fail if not equals
+    if (!failed) return;
+    snprintf(assert_message, 1024, "assertion failed: %s, expected %s%g but got %g (difference %g, precision %d) (%s:%d)",
+             expression, invert ? "not " : "", expected, actual, diff, precision, file, line);
+    longjmp(xtest_jmp, 1);
+}
+
+
+void xtest_skip(const char *reason) {
+    skip_reason = reason;
+    longjmp(xtest_jmp, 3);
+}
+
+void xtest_internal_start_group(const char *name) {
+#ifndef XTEST_ENABLE_SUBUNIT
+    printf("%*s%s:\n", xtest_indent, "", name);
+#endif
+    group_nesting[group_nesting_pos] = name;
+    group_nesting_pos += 1;
+    xtest_indent += XTEST_INDENT;
+}
+
+void xtest_internal_end_group() {
+    assert(group_nesting_pos > 0);
+    group_nesting_pos -= 1;
+    xtest_indent -= XTEST_INDENT;
+}
+
+void xtest_expect_assertion_failure() {
+    expecting_assertion = 1;
+}
\ No newline at end of file
diff --git a/xtest.h b/xtest.h
new file mode 100644
index 0000000..df3f41c
--- /dev/null
+++ b/xtest.h
@@ -0,0 +1,133 @@
+#ifndef XTEST_XTEST_H
+#define XTEST_XTEST_H
+
+#if defined(XTEST_XASSERT) && !defined(XTEST_SOURCE)
+#error "do not include xtest.h and xassert.h at the same time. xassert.h should only be included from your source files and xtest.h should only be included from your test files."
+#endif
+
+
+#include <stdio.h>
+#include <string.h>
+#include <assert.h>
+
+#ifndef XTEST_INDENT
+#define XTEST_INDENT 2
+#endif
+
+typedef void (*xtest_test_fn)(void *, void **);
+typedef void (*xtest_setup_fn)(void **);
+typedef void (*xtest_teardown_fn)(void *);
+
+typedef struct xtest_param_s xtest_param;
+
+typedef void *xtest_param_values[];
+
+
+struct xtest_param_s {
+    const char *name;
+    xtest_param_values *values;
+};
+
+enum xtest_type {
+    xtest_type_bool,
+    xtest_type_char,
+    xtest_type_short,
+    xtest_type_unsigned_short,
+    xtest_type_int,
+    xtest_type_unsigned_int,
+    xtest_type_long,
+    xtest_type_unsigned_long,
+    xtest_type_long_long,
+    xtest_type_unsigned_long_long,
+    xtest_type_float,
+    xtest_type_double,
+    xtest_type_long_double,
+    xtest_type_string,
+    xtest_type_void_pointer,
+    xtest_type_other,
+};
+
+
+void xtest_fail_assert(const char *expression, const char *file, int line, void *expected,
+                       void *actual, int invert, enum xtest_type type);
+void
+xtest_assert_float(double expected, double actual, int precision, int invert, const char *expression, const char *file,
+                   int line);
+
+void xtest_internal_run(xtest_test_fn fn, const char *name, xtest_param *params, xtest_setup_fn setup,
+                        xtest_teardown_fn teardown);
+
+void xtest_internal_start_group(const char *name);
+void xtest_internal_end_group();
+
+void xtest_skip(const char *reason);
+void xtest_expect_assertion_failure();
+int xtest_complete();
+
+#define xtest_run(fn) xtest_internal_run(fn, #fn, (void*)0, (void*)0, (void*)0)
+#define xtest_run_parameterized(fn, params) xtest_internal_run(fn, #fn, params, (void*)0, (void*)0)
+#define xtest_run_with_fixture(fn, setup, teardown) xtest_internal_run(fn, #fn, (void*)0, setup, teardown)
+#define xtest_run_parameterized_with_fixture(fn, params, setup, teardown) xtest_internal_run(fn, #fn, params, setup, teardown)
+
+#define xtest_group(name) xtest_internal_start_group(#name)
+#define xtest_end_group() xtest_internal_end_group()
+
+#define xtest_run_group(fn) do { \
+    xtest_group(fn);             \
+    fn();                        \
+    xtest_end_group();           \
+} while (0)
+
+#define xtest_get_param(type, idx, params) *((type*)(params)[idx])
+#define xtest_get_param_ptr(type, idx, params) (type)(params)[idx]
+
+
+#define xtest_get_type(val) _Generic(val, \
+    _Bool: xtest_type_bool, \
+    char: xtest_type_char, \
+    signed char: xtest_type_char, \
+    unsigned char: xtest_type_char, \
+    short: xtest_type_short, \
+    unsigned short: xtest_type_unsigned_short,\
+    int: xtest_type_int,\
+    unsigned int: xtest_type_unsigned_int,\
+    long: xtest_type_long,\
+    unsigned long: xtest_type_unsigned_long,\
+    long long: xtest_type_long_long,\
+    unsigned long long: xtest_type_unsigned_long_long,\
+    float: xtest_type_float,\
+    double: xtest_type_double,\
+    long double: xtest_type_long_double,\
+    const char *: xtest_type_string,\
+    void*:xtest_type_void_pointer,\
+    default: xtest_type_other)
+
+
+#define force_types_equal(a, b) (void) _Generic(a, \
+        typeof(b): (void*)0                                            \
+    )
+
+
+#define xtest_assert_(expr, s, actual, expected, invert) do { \
+        force_types_equal(expected, actual); \
+        int _xtest_res = (expr);                                              \
+        if (!(_xtest_res)) {                                \
+            typeof(actual) _xtest_a = actual;                    \
+            typeof(expected) _xtest_e = expected;                \
+            enum xtest_type _xtest_type = xtest_get_type(actual);             \
+            xtest_fail_assert(s, __FILE__, __LINE__, &_xtest_e, &_xtest_a, invert, _xtest_type); \
+        } \
+    } while(0)
+
+#define xtest_assert(e) xtest_assert_(!!(e), #e, (_Bool)(e), (_Bool)1, 0)
+#define xtest_assert_is(actual, expected) xtest_assert_((actual) == (expected), #actual " is " #expected, actual, expected, 0)
+#define xtest_assert_is_not(actual, expected) xtest_assert_((actual) != (expected), #actual " is not " #expected, actual, expected, 1)
+#define xtest_assert_float_is(actual, expected, precision) xtest_assert_float(expected, actual, precision, 0, #actual " is " #expected, __FILE__, __LINE__)
+#define xtest_assert_float_is_not(actual, expected, precision) xtest_assert_float(expected, actual, precision, 1, #actual " is not " #expected, __FILE__, __LINE__)
+#define xtest_assert_str_is(actual, expected) xtest_assert_(strcmp(actual, expected) == 0, #actual " is " #expected, (const char*)(actual), (const char*)(expected), 0)
+#define xtest_assert_str_is_not(actual, expected) xtest_assert_(strcmp(actual, expected) != 0, #actual " is not " #expected, (const char*)(actual), (const char*)(expected), 1)
+#define xtest_assert_mem_is(actual, expected, len) xtest_assert_(memcmp(actual, expected, len) == 0, #actual " is " #expected " (" #len " bytes)", NULL, NULL, 0)
+#define xtest_assert_mem_is_not(actual, expected, len) xtest_assert_(memcmp(actual, expected, len) != 0, #actual " is not " #expected " (" #len " bytes)", NULL, NULL, 1)
+
+
+#endif //XTEST_XTEST_H