I have written a template for a C program implementing a simple test framework.

If the program is run with the first parameter “test”, all subsequent parameters will be interpreted as a sequence of test cases (without the test_ prefix) to be executed. If no other parameters are specified after the first parameter “test”, all functions named test_* will be executed in the sequence specified in the TEST_CASES macro.

If one of the test cases fails, the program will report this and stop. In no test case fails, All test cases completed successfully will be logged.

Normally I would split the program into a header, general function definitions and test case files, but for SE, I thought it would be easier post the amalgamated code.

What do you think?

/*template.c - program template with a basic test framework*/ #include <stdio.h> #include <stdlib.h> #include <string.h>  /*To add a new test case for function foo(), add a line "X(foo) \" to the    TEST_CASES macro and then define the concrete test case function as -   result_t *test_foo(result_t *result){ // Code to test foo() goes here. If the test is successful, set  // result->rc = SUCCESS. Messages should be added to result->string using  // the cat_message function } */ #define TEST_CASES \   X(init_string) \ X(cat_message) \ X(parse_tc) \ X(get_all_tc)  /*Return codes*/ typedef enum {   SUCCESS,   ERR_MALLOC,   ERR_REALLOC,   ERR_GENERAL } rc_t;  /*String object : array of char with allocated size*/ typedef struct {   size_t size;   char *str; } string_t;  /*Test results object : string object with return code*/ typedef struct {   string_t *string;   rc_t rc; } result_t;  /*tc_func_t : test case function signature */ typedef result_t *(*tc_func_t)(result_t *result);  /*Test case execution sequence*/ typedef struct {   int num_tc; /* number in test cases in the tc_funcs array */   tc_func_t *tc_funcs; /*pointer to an array of test case functions*/ } tc_seq_t;  /*report_func_t : report results function signature*/ typedef rc_t (*report_func_t)(result_t *result);  /*Function prototypes*/ /*Initialise string object */ string_t *init_string(size_t size); /*Concatenate a message to the string object*/ string_t *cat_message(const char *message, string_t *string); /*Count number of test cases in TEST_CASES*/ int count_tc(void); /*Create a test case set from the command line parameters*/ tc_seq_t *parse_tc(int argc, char **argv); /*Create a test case set with all test cases specified in the TEST_CASES macro*/ tc_seq_t *get_all_tc(void); /*Run all test cases in the test case sequence and report results*/ result_t *run_tests(tc_seq_t *tc_seq, report_func_t report_func,      result_t *result); /*Write results to STDOUT*/ rc_t print_stdout(result_t *result); /*Test case prototypes are generated by the X macro expansion*/ #define X(name) result_t *test_ ## name(result_t *result); TEST_CASES #undef X  string_t *init_string(size_t size){   string_t *string = malloc(sizeof *string);   /*If an error occurs, return a NULL pointer*/   if (string == NULL) return NULL;   string->str = malloc(size);   if (string->str == NULL){     free(string);     return NULL;   }   string->size = size;   *string->str = '';   return string; }  string_t *cat_message(const char *message, string_t *string){   /*If the caller does supply the correct parameters, return the string object     * unchanged*/   if (message == NULL || string == NULL || string->str == NULL) return string;   while (strlen(message) >= string->size - strlen(string->str)){     /*If the memory allocated to the string object is insufficient, keep       * doubling the allocation until it is enough to concancenate the message*/     string->str = realloc(string->str, string->size * 2);     if (string->str == NULL) return string;      string->size *= 2;   }   memcpy(string->str+strlen(string->str), message, strlen(message)+1);   return string; }  int count_tc(void){   int num_tc = 0; #define X(name) num_tc++;   TEST_CASES #undef X     return num_tc; }  tc_seq_t *parse_tc(int argc, char **argv){   /*If the first parameter is not "test", return a NULL pointer*/   if (argc == 1 || strcmp(argv[1], "test")) return NULL;   /*if the first and only parameter is "test", return all test cases */   if (argc == 2) return get_all_tc();   /*return test cases specified in the parameters after "test"*/   tc_seq_t *tc_set = malloc(sizeof *tc_set);   tc_set->tc_funcs = malloc((argc - 2) * sizeof *tc_set->tc_funcs);   /*If an error occurs, return a NULL pointer*/   if (tc_set->tc_funcs == NULL) {     free(tc_set);     return NULL;   }   int tc_ind = 0;   /*Fill the array testcase->tc_funcs[] with pointers to test functions*/   for (int i = 2; i < argc; i++){ #define X(name) if (!strcmp(argv[i], #name)) \     {tc_set->tc_funcs[tc_ind] = test_ ## name; tc_ind++; break;}     TEST_CASES #undef X   }   tc_set->num_tc = argc - 2;   return tc_set; }  tc_seq_t *get_all_tc(void){   tc_seq_t *tc_set = malloc(sizeof *tc_set);   if (tc_set == NULL) return NULL;   tc_set->tc_funcs = malloc(count_tc() * sizeof *tc_set->tc_funcs);   /*If an error occurs, return a NULL pointer*/   if (tc_set->tc_funcs == NULL) {     free(tc_set);     return NULL;   }   tc_set->num_tc = count_tc();   /*Fill the array testcase->tc_funcs[] with pointers to test functions*/   int tc = -1; #define X(name) tc++; tc_set->tc_funcs[tc] = test_ ## name;   TEST_CASES #undef X     return tc_set; }  result_t *run_tests(tc_seq_t *tc_seq, report_func_t report_func,      result_t *result){   for (int tc_ind = 0; tc_ind < tc_seq->num_tc; tc_ind++) {     result = tc_seq->tc_funcs[tc_ind](result);     if (result->rc != SUCCESS) break;   }   if (result->rc == SUCCESS) cat_message(       "All test cases completed successfully\n", result->string);   free(tc_seq->tc_funcs);   free(tc_seq);   report_func(result);   return result; }  rc_t print_stdout(result_t *result){   if (result == NULL) return ERR_GENERAL;   if (result->string == NULL) return ERR_GENERAL;   if (result->string->str == NULL) return ERR_GENERAL;   printf("%s", result->string->str);   printf("Return code: %d\n", result->rc);   return SUCCESS; }  int main(int argc, char **argv){   string_t *string = init_string(1024);   if (string == NULL) return ERR_MALLOC;   string = cat_message("Start log\n", string);   if (string == NULL) return ERR_REALLOC;   result_t *result = malloc(sizeof *result);   if (result == NULL) {      free(string->str);     free(string);     return ERR_GENERAL;   }    result->string = string;   result->rc = SUCCESS;   tc_seq_t *tc_seq = parse_tc(argc, argv);   if (tc_seq != NULL) result = run_tests(tc_seq, print_stdout, result);   free(string->str);   free(string);   free(result); }  result_t *test_init_string(result_t *result){   string_t *string = init_string(10);   if (string == NULL){     result->rc = ERR_MALLOC;     result->string = cat_message("init_string failed\n", result->string);     return result;   }   if (string->size == 10 && !strcmp(string->str, "")){     result->rc = SUCCESS;   } else {     result->rc = ERR_GENERAL;     result->string = cat_message("init_string failed\n", result->string);   }   free(string->str);   free(string);   return result; }  result_t *test_cat_message(result_t *result){   string_t *string = init_string(10);   if (string == NULL){     result->rc = ERR_MALLOC;     return result;   }   string = cat_message("foo", string);   if (string == NULL){     result->rc = ERR_REALLOC;     result->string = cat_message("cat_message failed\n", result->string);     return result;   }   string = cat_message("bar", string);   if (string == NULL){     result->string = cat_message("cat_message failed\n", result->string);     result->rc = ERR_REALLOC;     return result;   }   if (string->size == 10 && !strcmp(string->str, "foobar")){     result->rc = SUCCESS;   } else {     result->string = cat_message("cat_message failed\n", result->string);     result->rc = ERR_GENERAL;   }   free(string->str);   free(string);   return result; }  result_t *test_parse_tc(result_t *result){   char *argv[] = {"template", "test", "parce_tc", "get_all_tc"};   tc_seq_t *tc = parse_tc(4, argv);   if (tc == NULL){     result->string = cat_message("parse_tc failed\n", result->string);     result->rc = ERR_GENERAL;     return result;   }   if (tc->num_tc == 2) {     result->rc = SUCCESS;   } else {     result->rc = ERR_GENERAL;     result->string = cat_message("parse_tc failed\n", result->string);   }   free(tc->tc_funcs);   free(tc);   return result; }  result_t *test_get_all_tc(result_t *result){   tc_seq_t *tc = get_all_tc();   if (tc == NULL){     result->rc = ERR_GENERAL;     result->string = cat_message("get_all_tc failed\n", result->string);     return result;   }   if (tc->num_tc == count_tc()) {     result->rc = SUCCESS;   } else {     result->rc = ERR_GENERAL;     result->string = cat_message("get_all_tc failed\n", result->string);   }   free(tc->tc_funcs);   free(tc);   return result; }