Added more unit tests

src/test/java/com/mattrixwv/project_euler/problems/TestProblem20.java

@@ -0,0 +1,60 @@
+package com.mattrixwv.project_euler.problems;
+
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertFalse;
+import static org.junit.jupiter.api.Assertions.assertThrows;
+
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.extension.ExtendWith;
+import org.mockito.InjectMocks;
+import org.mockito.junit.jupiter.MockitoExtension;
+
+import com.mattrixwv.project_euler.exceptions.Unsolved;
+
+
+@ExtendWith(MockitoExtension.class)
+public class TestProblem20 extends BaseTest{
+	@InjectMocks
+	private Problem20 problem;
+
+
+	@Test
+	@Override
+	public void testDescription(){
+		assertEquals("What is the sum of the digits of 100!?", problem.getDescription());
+		assertFalse(problem.getSolved());
+	}
+
+	@Test
+	@Override
+	public void testSolve(){
+		assertThrows(Unsolved.class, () -> { problem.getNumber(); });
+		assertThrows(Unsolved.class, () -> { problem.getNumberString(); });
+		assertThrows(Unsolved.class, () -> { problem.getSum(); });
+
+		problem.solve();
+
+		//Verify result
+		assertEquals(648, problem.getSum());
+		assertEquals(String.format("100! = 93326215443944152681699238856266700490715968264381621468592963895217599993229915608941463976156518286253697920827223758251185210916864000000000000000000000000%nThe sum of the digits is: 648"), problem.getResult());
+		//Verify the problem variables and functions were called
+		verifyProblem(problem);
+
+		//Verify the problem won't be run again
+		verifyProblemSecondRun(problem);
+	}
+
+	@Test
+	@Override
+	public void testReset(){
+		problem.reset();
+
+		//Verify solved was reset
+		assertFalse(problem.getSolved());
+		super.testReset();
+
+		//Verify the problem can be solved again
+		testSolve();
+	}
+}