Add oving 4

src/test/java/oving4/twitter/TweetTest.java

@@ -0,0 +1,93 @@
+package oving4.twitter;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertNull;
+import static org.junit.jupiter.api.Assertions.assertThrows;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.DisplayName;
+import org.junit.jupiter.api.Test;
+
+public class TweetTest {
+
+	private Tweet retweet1;
+	private Tweet tweet;
+	private TwitterAccount kari;
+	private TwitterAccount nils;
+	private TwitterAccount ole;
+
+	@BeforeEach
+	public void setUp() {
+		nils = new TwitterAccount("Nils");
+		ole = new TwitterAccount("Ole");
+		kari = new TwitterAccount("Kari");
+		tweet = new Tweet(nils, "Kvitre!");
+		retweet1 = null;
+	}
+
+	@Test
+	@DisplayName("Check that the constructor initializes correctly")
+	public void testNullInConstructors() {
+		assertEquals("Kvitre!", tweet.getText());
+		assertEquals(nils, tweet.getOwner());
+
+		assertThrows(IllegalArgumentException.class, () -> {
+			new Tweet(null, "Kvitre!");
+		}, "The tweet must have an owner");
+
+		assertThrows(IllegalArgumentException.class, () -> {
+			new Tweet(nils, (String) null);
+		}, "The tweet must have text");
+
+		assertThrows(IllegalArgumentException.class, () -> {
+			new Tweet(null, tweet);
+		}, "The tweet must have an owner");
+
+		assertThrows(IllegalArgumentException.class, () -> {
+			new Tweet(nils, (Tweet) null);
+		}, "The tweet must have an original tweet");
+	}
+
+	@Test
+	public void constructorNewTweet() {
+		assertEquals("Kvitre!", tweet.getText(),
+				"The constructor initialized the tweet with incorrect text");
+		assertEquals(nils, tweet.getOwner(),
+				"The constructor initialized the tweet with the wrong owner");
+	}
+
+	@Test
+	@DisplayName("Check that retweet has the same text but a different owner")
+	public void constructorRetweet() {
+		retweet1 = new Tweet(ole, tweet);
+		assertEquals("Kvitre!", retweet1.getText());
+		assertEquals(ole, retweet1.getOwner());
+
+		assertThrows(RuntimeException.class, () -> {
+			new Tweet(nils, tweet);
+		}, "A person should not be able to retweet themselves");
+	}
+
+	@Test
+	@DisplayName("Check that the original tweet is always correct")
+	public void getOriginalTweet() {
+		assertNull(tweet.getOriginalTweet());
+
+		retweet1 = new Tweet(ole, tweet);
+		assertEquals(tweet, retweet1.getOriginalTweet());
+		assertEquals(retweet1.getOriginalTweet().getText(), retweet1.getText());
+		assertEquals(tweet, retweet1.getOriginalTweet());
+		assertEquals(retweet1.getOriginalTweet().getText(), retweet1.getText());
+	}
+
+	@Test
+	@DisplayName("Check that retweet count increases when a tweet is retweeted")
+	public void getRetweetCount() {
+		assertEquals(0, tweet.getRetweetCount());
+
+		new Tweet(ole, tweet);
+		assertEquals(1, tweet.getRetweetCount());
+
+		new Tweet(kari, tweet);
+		assertEquals(2, tweet.getRetweetCount());
+	}
+}