Add some tests to problem 74

src/test/java/com/github/pedrovgs/problem74/BubbleSortTest.java

@@ -0,0 +1,58 @@
+package com.github.pedrovgs.problem74;
+
+import org.junit.Before;
+import org.junit.Test;
+
+import static org.junit.Assert.assertArrayEquals;
+
+/**
+ * @author Pedro Vicente Gómez Sánchez.
+ */
+public class BubbleSortTest {
+
+  private BubbleSort bubbleSort;
+
+  @Before public void setUp() {
+    bubbleSort = new BubbleSort();
+  }
+
+  @Test(expected = IllegalArgumentException.class) public void shouldNotAcceptNullArrays() {
+    bubbleSort.sort(null);
+  }
+
+  @Test public void shouldNotModifyArrayIfIsAlreadySorted() {
+    int[] input = { 1, 2, 3, 4 };
+
+    bubbleSort.sort(input);
+
+    int[] expectedArray = { 1, 2, 3, 4 };
+    assertArrayEquals(expectedArray, input);
+  }
+
+  @Test public void shouldSortArrayWhenTheInputDataIsInDescendingOrder() {
+    int[] input = { 4, 3, 2, 1 };
+
+    bubbleSort.sort(input);
+
+    int[] expectedArray = { 1, 2, 3, 4 };
+    assertArrayEquals(expectedArray, input);
+  }
+
+  @Test public void shouldSortArrayPartiallySorted() {
+    int[] input = { 1, 2, 4, 3 };
+
+    bubbleSort.sort(input);
+
+    int[] expectedArray = { 1, 2, 3, 4 };
+    assertArrayEquals(expectedArray, input);
+  }
+
+  @Test public void shouldSortArray() {
+    int[] input = { 3, 4, 1, 2 };
+
+    bubbleSort.sort(input);
+
+    int[] expectedArray = { 1, 2, 3, 4 };
+    assertArrayEquals(expectedArray, input);
+  }
+}