Merge pull request #889 from FridaTveit/SimpleLinkedListUseGenerics

simple-linked-list: use generics

exercises/simple-linked-list/src/test/java/SimpleLinkedListTest.java

 
     @Test
     public void aNewListIsEmpty() {
-        SimpleLinkedList list = new SimpleLinkedList();
+        SimpleLinkedList<Integer> list = new SimpleLinkedList<>();
         assertThat(list.size(), is(0));
     }
 
     @Ignore("Remove to run test")
     @Test
     public void canCreateFromArray() {
-        Integer[] values = new Integer[]{1, 2, 3};
-        SimpleLinkedList list = new SimpleLinkedList(values);
+        Character[] values = new Character[]{'1', '2', '3'};
+        SimpleLinkedList<Character> list = new SimpleLinkedList<Character>(values);
         assertThat(list.size(), is(3));
     }
 
     @Test
     public void popOnEmptyListWillThrow() {
         expectedException.expect(NoSuchElementException.class);
-        SimpleLinkedList list = new SimpleLinkedList();
+        SimpleLinkedList<String> list = new SimpleLinkedList<String>();
         list.pop();
     }
 
     @Ignore("Remove to run test")
     @Test
     public void popReturnsLastAddedElement() {
-        SimpleLinkedList list = new SimpleLinkedList();
+        SimpleLinkedList<Integer> list = new SimpleLinkedList<Integer>();
         list.push(9);
         list.push(8);
         assertThat(list.size(), is(2));
     @Ignore("Remove to run test")
     @Test
     public void reverseReversesList() {
-        SimpleLinkedList list = new SimpleLinkedList();
-        list.push(9);
-        list.push(8);
-        list.push(7);
-        list.push(6);
-        list.push(5);
+        SimpleLinkedList<String> list = new SimpleLinkedList<String>();
+        list.push("9");
+        list.push("8");
+        list.push("7");
+        list.push("6");
+        list.push("5");
         list.reverse();
-        assertThat(list.pop(), is(9));
-        assertThat(list.pop(), is(8));
-        assertThat(list.pop(), is(7));
-        assertThat(list.pop(), is(6));
-        assertThat(list.pop(), is(5));
+        assertThat(list.pop(), is("9"));
+        assertThat(list.pop(), is("8"));
+        assertThat(list.pop(), is("7"));
+        assertThat(list.pop(), is("6"));
+        assertThat(list.pop(), is("5"));
     }
 
     @Ignore("Remove to run test")
     @Test
     public void canReturnListAsArray() {
-        SimpleLinkedList list = new SimpleLinkedList();
-        list.push(9);
-        list.push(8);
-        list.push(7);
-        list.push(6);
-        list.push(5);
-        Integer[] expected = {5, 6, 7, 8, 9};
-        assertArrayEquals(expected, list.asArray(Integer.class));
+        SimpleLinkedList<Character> list = new SimpleLinkedList<Character>();
+        list.push('9');
+        list.push('8');
+        list.push('7');
+        list.push('6');
+        list.push('5');
+        Character[] expected = {'5', '6', '7', '8', '9'};
+        assertArrayEquals(expected, list.asArray(Character.class));
     }
 
     @Ignore("Remove to run test")
     @Test
     public void canReturnEmptyListAsEmptyArray() {
-        SimpleLinkedList list = new SimpleLinkedList();
+        SimpleLinkedList<Object> list = new SimpleLinkedList<Object>();
         Object[] expected = {};
         assertArrayEquals(expected, list.asArray(Object.class));
     }