created test code

src/test/main.c

@@ -1,17 +1,28 @@
 #include <stdio.h>
 #include <stdlib.h>
+#include <string.h>
 
 #include "../../include/encrypter.h"
 #include "../../include/decrypter.h"
 
+#define TEST_TEXT "Pepa smrdí."
+#define TEST_KEY "lZwOBFvjJEmaYRIaKsALKLkSeJvXhFPbZIRNFbjQRNyiOuLTexhgOpObHzyQgNT"
+
 int
 main(int args, char *argv[])
 {
-    char *text = encryptText("Pepa smrdí.", "lZwOBFvjJEmaYRIaKsALKLkSeJvXhFPbZIRNFbjQRNyiOuLTexhgOpObHzyQgNT");
+    char *text = encryptText(TEST_TEXT, TEST_KEY);
-    printf("%s\n", text);
+    text = decryptText(text, TEST_KEY);
 
-    text = decryptText(text, "lZwOBFvjJEmaYRIaKsALKLkSeJvXhFPbZIRNFbjQRNyiOuLTexhgOpObHzyQgNT");
+    if (strcmp(text, TEST_TEXT) == 0)
-    printf("%s\n", text);
+    {
+        printf("Test successful!\n");
+    }
+    else
+    {
+        fprintf(stderr, "Test failed!\n");
+        exit(1);
+    }
 
 	free(text);
     return 0;