Add unit tests for org.bukkit.util.StringUtil

By: Wesley Wolfe <weswolf@aol.com>

paper-api/src/test/java/org/bukkit/util/StringUtilTest.java

@@ -0,0 +1,61 @@
+package org.bukkit.util;
+
+import static org.hamcrest.Matchers.*;
+import static org.junit.Assert.*;
+
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.List;
+
+import org.junit.Test;
+
+import com.google.common.collect.ImmutableList;
+
+public class StringUtilTest {
+
+    @Test(expected=NullPointerException.class)
+    public void nullPrefixTest() {
+        StringUtil.startsWithIgnoreCase("String", null);
+    }
+
+    @Test(expected=IllegalArgumentException.class)
+    public void nullStringTest() {
+        StringUtil.startsWithIgnoreCase(null, "String");
+    }
+
+    @Test(expected=IllegalArgumentException.class)
+    public void nullCollectionTest() {
+        StringUtil.copyPartialMatches("Token", ImmutableList.<String>of(), null);
+    }
+
+    @Test(expected=IllegalArgumentException.class)
+    public void nullIterableTest() {
+        StringUtil.copyPartialMatches("Token", null, new ArrayList<String>());
+    }
+
+    @Test(expected=IllegalArgumentException.class)
+    public void nullTokenTest() {
+        StringUtil.copyPartialMatches(null, ImmutableList.<String>of(), new ArrayList<String>());
+    }
+
+    @Test
+    public void copyTokenTest() {
+        String token = "ab";
+        Iterable<String> original = ImmutableList.of("ab12", "aC561", "AB5195", "Ab76", "", "a");
+        List<String> expected =     ImmutableList.of("ab12",          "AB5195", "Ab76"         );
+        List<String> list = new ArrayList<String>();
+        assertThat(StringUtil.copyPartialMatches(token, original, list), is(expected));
+        assertThat(StringUtil.copyPartialMatches(token, original, list), is(sameInstance(list)));
+        assertThat(list.size(), is(expected.size() * 2));
+    }
+
+    @Test(expected=UnsupportedOperationException.class)
+    public void copyUnsupportedTest() {
+        StringUtil.copyPartialMatches("token", ImmutableList.of("token1", "token2"), ImmutableList.of());
+    }
+
+    @Test(expected=IllegalArgumentException.class)
+    public void copyNullTest() {
+        StringUtil.copyPartialMatches("token", Arrays.asList("token1", "token2", null), new ArrayList<String>());
+    }
+}