test: add empty args exception check (#1859)

* checking empty args in unit tests

android/CouchbaseLite/src/androidTest/java/com/couchbase/lite/DatabaseTest.java

@@ -23,7 +23,9 @@
 
 import org.junit.After;
 import org.junit.Before;
+import org.junit.Rule;
 import org.junit.Test;
+import org.junit.rules.ExpectedException;
 
 import java.io.File;
 import java.util.ArrayList;
@@ -43,6 +45,9 @@
 public class DatabaseTest extends BaseTest {
     final static String kDatabaseTestBlob = "i'm blob";
 
+    @Rule
+    public ExpectedException thrown = ExpectedException.none();
+
     //---------------------------------------------
     //  Helper methods
     //---------------------------------------------
@@ -1390,6 +1395,15 @@ public void testCreateIndex() throws CouchbaseLiteException {
         Log.i(TAG, "db.getIndexes() -> " + db.getIndexes());
     }
 
+    @Test
+    public void testIndexBuilderEmptyArgs() {
+        thrown.expect(IllegalArgumentException.class);
+        IndexBuilder.fullTextIndex(null);
+
+        thrown.expect(IllegalArgumentException.class);
+        IndexBuilder.valueIndex(null);
+    }
+
     @Test
     public void testCreateSameIndexTwice() throws CouchbaseLiteException {
         // Create index with first name:

android/CouchbaseLite/src/androidTest/java/com/couchbase/lite/QueryTest.java

@@ -1637,6 +1637,29 @@ public void testJoinWithArrayContains() throws Exception {
             Log.e(TAG, "RESULT: " + r.toMap());
     }
 
+    @Test
+    public void testJoinWithEmptyArgs() {
+        DataSource mainDS = DataSource.database(this.db).as("main");
+
+        thrown.expect(IllegalArgumentException.class);
+        QueryBuilder.select(SelectResult.all()).from(mainDS).join(null);
+
+        thrown.expect(IllegalArgumentException.class);
+        QueryBuilder.select(SelectResult.all()).from(mainDS).where(null);
+
+        thrown.expect(IllegalArgumentException.class);
+        QueryBuilder.select(SelectResult.all()).from(mainDS).groupBy(null);
+
+        thrown.expect(IllegalArgumentException.class);
+        QueryBuilder.select(SelectResult.all()).from(mainDS).orderBy(null);
+
+        thrown.expect(IllegalArgumentException.class);
+        QueryBuilder.select(SelectResult.all()).from(mainDS).limit(null);
+
+        thrown.expect(IllegalArgumentException.class);
+        QueryBuilder.select(SelectResult.all()).from(mainDS).limit(null, null);
+    }
+
     //https://github.com/couchbase/couchbase-lite-android/issues/1785
     @Test
     public void testResultToMapWithBoolean() throws Exception {