content: package by.andd3dfx.numeric;
  
  import org.junit.Test;
  
  import static by.andd3dfx.numeric.ValidNumber.isNumber;
  import static org.junit.Assert.assertFalse;
  import static org.junit.Assert.assertTrue;
  
  public class ValidNumberTest {
  
      @Test
      public void testIsNumber() {
          assertTrue(isNumber("2"));
          assertTrue(isNumber("0089"));
          assertTrue(isNumber("-0.1"));
          assertTrue(isNumber("+3.14"));
          assertTrue(isNumber("4."));
          assertTrue(isNumber("-.9"));
          assertTrue(isNumber("2e10"));
          assertTrue(isNumber("-90E3"));
          assertTrue(isNumber("3e+7"));
          assertTrue(isNumber("+6e-1"));
          assertTrue(isNumber("53.5e93"));
          assertTrue(isNumber("-123.456e789"));
  
          assertFalse(isNumber("abc"));
          assertFalse(isNumber("1a"));
          assertFalse(isNumber("1e"));
          assertFalse(isNumber("e3"));
          assertFalse(isNumber("99e2.5"));
          assertFalse(isNumber("--6"));
          assertFalse(isNumber("-+3"));
          assertFalse(isNumber("95a54e53"));
      }
  }