I have only one method main. How to check System.out.println() and replace Scanner to input values automatically using JUnit?
P.S. Please, provide some solutions...
public static void main(String[] args) {
Scanner scanner = new Scanner(System.in);
int[] arr = new int[4];
for (int i = 0; i < arr.length; i++) {
arr[i] = scanner.nextInt();
}
for (int i = 0; i < arr.length; i++) {
int res = 0;
int k = 0;
int num = arr[i];
/*.....*/
System.out.println(num);
}
}
Ideally, extract the awkward dependencies so that you can test without them. Change main
to simply:
public static void main(String[] args) {
doWork(new Scanner(System.in), System.out);
}
// TODO: Rename to something meaningful
public static void doWork(Scanner input, PrintStream output) {
// Remainder of code
}
(Consider using a Writer
instead of a PrintStream
for output
.)
Then you don't really need to unit test main
- but you can test doWork
using a Scanner
based on a StringReader
, and output based on a StringWriter
, providing whatever input you want and checking the output.