NEW: Ebean.checkUniqueness - you can check a bean, if save would work (#1303)

src/test/java/org/tests/insert/TestInsertCheckUnique.java

@@ -0,0 +1,73 @@
+package org.tests.insert;
+
+import io.ebean.BaseTestCase;
+
+import org.junit.Before;
+import org.junit.Test;
+import org.tests.model.draftable.Document;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+public class TestInsertCheckUnique extends BaseTestCase {
+
+  @Before
+  public void clearDb() {
+    server().find(Document.class).asDraft().where().contains("title", "UniqueKey").delete();
+    server().find(Document.class).asDraft().where().isNull("title").delete();
+  }
+  
+  @Test
+  public void insert_duplicateKey() {
+    server().beginTransaction();
+    try {
+      Document doc1 = new Document();
+      doc1.setTitle("ThisIsAUniqueKey");
+      doc1.setBody("one");
+
+      assertThat(server().checkUniqueness(doc1)).isEmpty();
+      doc1.save();
+
+      Document doc2 = new Document();
+      doc2.setTitle("ThisIsAUniqueKey");
+      doc2.setBody("clashes with doc1");
+
+      assertThat(server().checkUniqueness(doc2)).isEmpty();
+      ;
+
+      server().publish(doc1.getClass(), doc1.getId());
+
+      assertThat(server().checkUniqueness(doc2).toString()).contains("title");
+    } finally {
+      server().endTransaction();
+    }
+  }
+  
+  @Test
+  public void insert_duplicateNull() {
+    server().beginTransaction();
+    try {
+      Document doc1 = new Document();
+      doc1.setTitle(null);
+      doc1.setBody("one");
+
+      assertThat(server().checkUniqueness(doc1)).isEmpty();
+      doc1.save();
+
+      Document doc2 = new Document();
+      doc2.setTitle(null);
+      doc2.setBody("clashes with doc1");
+
+      assertThat(server().checkUniqueness(doc2)).isEmpty();
+ 
+      server().publish(doc1.getClass(), doc1.getId());
+
+      assertThat(server().checkUniqueness(doc2)).isEmpty();
+
+      doc2.save();
+      server().publish(doc2.getClass(), doc2.getId());
+    } finally {
+      server().endTransaction();
+    }
+  }
+
+}