TestCase

Problem_X_Test.java

package week_5;



import static org.junit.Assert.*;

import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.PrintStream;

import org.junit.After;
import org.junit.Before;
import org.junit.Test;

public class Problem_X_Test {

	private final ByteArrayOutputStream outContent = new ByteArrayOutputStream();
	private final ByteArrayOutputStream errContent = new ByteArrayOutputStream();

	private final InputStream originalIn = System.in;
	private final PrintStream originalOut = System.out;
	private final PrintStream originalErr = System.err;

	@Before
	public void setUpStreams() {
		System.setOut(new PrintStream(outContent));
		System.setErr(new PrintStream(errContent));
	}

	@After
	public void cleanUpStreams() {
		System.setIn(originalIn);
		System.setOut(originalOut);
		System.setErr(originalErr);
	}

	@Test
	public void sampleInput1() throws NumberFormatException, IOException {

		// specify input here
		String sampleInput = String.join(System.getProperty("line.separator"),
			    "2",
			    "2",
			    "3 4",
			    "5 6",
			    "7 8",
			    "",
			    "9",
			    "10 11 12",
			    "13 14 15"
			);
		
		// redirect stdIn
		System.setIn(new ByteArrayInputStream(sampleInput.getBytes()));

		// specify expected output
		String expectedOut = "Case #1: \nCase #2: \nCase #3: \nCase #4: \nCase #5: \n";

		// specify expected output
		String expectedOut2 = String.join(System.getProperty("line.separator"),
			    "Case #1: yes",
			    "Case #2: no",
			    ""
			);
		
		// call some method which will read from stdin and output to stdout
		Problem_X.main(null);

		// stores actual output
		String actualOut = outContent.toString();

		// compares expected and actual output
		assertEquals(expectedOut, actualOut);
	}

}