Implement test to check if the file opens

tests/test_currentCustomerAccountBalance.c

@@ -12,8 +12,7 @@ void tearDown(void)
 {
 }
 
-void test_fetchBalanceFromBalanceString(void)
-{
+void test_fetchBalanceFromBalanceString(void) {
     char  balanceString[5][100] = {
         "balance=0",
         "balance=100",
@@ -43,4 +42,16 @@ void test_fetchBalanceFromBalanceString(void)
 }
 
 
+void test_checkFileOpen(void) {
+
+    FILE *file = fopen(CUSTOMER_DATA_FILE, "r");
+
+    TEST_ASSERT_TRUE(file);
+
+    fclose(file);
+}
+
+
+
+
 #endif // TEST