/*
 *  Simple example of a CUnit unit test.
 *
 *  This program (crudely) demonstrates a very simple "black box"
 *  test of the standard library functions fprintf() and fread().
 *  It uses suite initialization and cleanup functions to open
 *  and close a common temporary file used by the test functions.
 *  The test functions then write to and read from the temporary
 *  file in the course of testing the library functions.
 *
 *  The 2 test functions are added to a single CUnit suite, and
 *  then run using the CUnit Basic interface.  The output of the
 *  program (on CUnit version 2.0-2) is:
 *
 *           CUnit : A Unit testing framework for C.
 *           http://cunit.sourceforge.net/
 *
 *       Suite: Suite_1
 *         Test: test of fprintf() ... passed
 *         Test: test of fread() ... passed
 *
 *       --Run Summary: Type      Total     Ran  Passed  Failed
 *                      suites        1       1     n/a       0
 *                      tests         2       2       2       0
 *                      asserts       5       5       5       0
 */

#include <stdio.h>
#include <string.h>
#include "CUnit/Basic.h"

/* Pointer to the file used by the tests. */
static FILE *temp_file = NULL;

/* The suite initialization function.
 * Opens the temporary file used by the tests.
 * Returns zero on success, non-zero otherwise.
 */
int init_suite1 (void)
{
    if (NULL == (temp_file = fopen ("temp.txt", "w+"))) {
        return -1;
    } else {
        return 0;
    }
}

/* The suite cleanup function.
 * Closes the temporary file used by the tests.
 * Returns zero on success, non-zero otherwise.
 */
int clean_suite1 (void)
{
    if (0 != fclose (temp_file)) {
        return -1;
    } else {
        temp_file = NULL;
        return 0;
    }
}

/* Simple test of fprintf().
 * Writes test data to the temporary file and checks
 * whether the expected number of bytes were written.
 */
void testFPRINTF (void)
{
    int i1 = 10;

    if (NULL != temp_file) {
        CU_ASSERT (0 == fprintf (temp_file, ""));
        CU_ASSERT (2 == fprintf (temp_file, "Q\n"));
        CU_ASSERT (7 == fprintf (temp_file, "i1 = %d", i1));
    }
}

/* Simple test of fread().
 * Reads the data previously written by testFPRINTF()
 * and checks whether the expected characters are present.
 * Must be run after testFPRINTF().
 */
void testFREAD (void)
{
    char buffer[20];

    if (NULL != temp_file) {
        rewind (temp_file);
        CU_ASSERT (9 == fread (buffer, sizeof (unsigned char), 20, temp_file));
        CU_ASSERT (0 == strncmp (buffer, "Q\ni1 = 10", 9));
    }
}

/* The main() function for setting up and running the tests.
 * Returns a CUE_SUCCESS on successful running, another
 * CUnit error code on failure.
 */
int main ()
{
    CU_pSuite pSuite = NULL;

    /*
     * initialize the CUnit test registry
     */
    if (CUE_SUCCESS != CU_initialize_registry ())
        return CU_get_error ();

    /*
     * add a suite to the registry
     */
    pSuite = CU_add_suite ("Suite_1", init_suite1, clean_suite1);
    if (NULL == pSuite) {
        CU_cleanup_registry ();
        return CU_get_error ();
    }

    /*
     * add the tests to the suite
     */
    /*
     * NOTE - ORDER IS IMPORTANT - MUST TEST fread() AFTER fprintf()
     */
    if ((NULL == CU_add_test (pSuite, "test of fprintf()", testFPRINTF)) ||
        (NULL == CU_add_test (pSuite, "test of   fread()", testFREAD))) {
        CU_cleanup_registry ();
        return CU_get_error ();
    }

    /*
     * Run all tests using the CUnit Basic interface
     */
    CU_basic_set_mode (CU_BRM_VERBOSE);
    CU_basic_run_tests ();
    CU_cleanup_registry ();

    return CU_get_error ();
}