OnJava8-Examples/validating/tests/StringInverterTests.java

// validating/tests/StringInverterTests.java
// (c)2021 MindView LLC: see Copyright.txt
// We make no guarantees that this code is fit for any purpose.
// Visit http://OnJava8.com for more book information.
package validating;
import java.util.*;
import java.util.stream.*;
import org.junit.jupiter.api.*;
import static org.junit.jupiter.api.Assertions.*;

public class StringInverterTests {
  StringInverter inverter = new Inverter4();
  @BeforeAll
  static void startMsg() {
    System.out.println(">>> StringInverterTests <<<");
  }
  @Test
  void basicInversion1() {
    String in = "Exit, Pursued by a Bear.";
    String out = "eXIT, pURSUED BY A bEAR.";
    assertEquals(inverter.invert(in), out);
  }
  @Test
  void basicInversion2() {
    assertThrows(Error.class, () -> {
      assertEquals(inverter.invert("X"), "X");
    });
  }
  @Test
  void disallowedCharacters() {
    String disallowed = ";-_()*&^%$#@!~`0123456789";
    String result = disallowed.chars()
      .mapToObj(c -> {
        String cc = Character.toString((char)c);
        try {
          inverter.invert(cc);
          return "";
        } catch(RuntimeException e) {
          return cc;
        }
      }).collect(Collectors.joining(""));
    assertEquals(result, disallowed);
  }
  @Test
  void allowedCharacters() {
    String lowcase = "abcdefghijklmnopqrstuvwxyz ,.";
    String upcase =  "ABCDEFGHIJKLMNOPQRSTUVWXYZ ,.";
    assertEquals(inverter.invert(lowcase), upcase);
    assertEquals(inverter.invert(upcase), lowcase);
  }
  @Test
  void lengthNoGreaterThan30() {
    String str = "xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx";
    assertTrue(str.length() > 30);
    assertThrows(RuntimeException.class, () -> {
      inverter.invert(str);
    });
  }
  @Test
  void lengthLessThan31() {
    String str = "xxxxxxxxxxxxxxxxxxxxxxxxxxxxxx";
    assertTrue(str.length() < 31);
    inverter.invert(str);
  }
}