Implement assert_str and assert_not_null and update tests

v0/test.c

@@ -1,6 +1,7 @@
 #include "test.h"
 #include <setjmp.h>
 #include <stdio.h>
+#include <string.h>
 
 static jmp_buf s_testJmp;
 static const char* s_failMsg;
@@ -10,6 +11,18 @@ void fail(const char* msg) {
     longjmp(s_testJmp, 1);
 }
 
+void assert_not_null(void* ptr, const char* msg) {
+    if (ptr == NULL) {
+        fail(msg);
+    }
+}
+
+void assert_str(const char* expected, const char* actual, const char* msg) {
+    if (expected == NULL || actual == NULL || strcmp(expected, actual) != 0) {
+        fail(msg);
+    }
+}
+
 typedef struct {
     const char* name;
     Test func;