Add test

querydsl-collections/src/test/java/com/mysema/query/collections/GroupBy4Test.java

@@ -0,0 +1,51 @@
+package com.mysema.query.collections;
+
+import static com.mysema.query.group.GroupBy.groupBy;
+import static com.mysema.query.group.GroupBy.map;
+import static org.junit.Assert.assertEquals;
+
+import java.util.List;
+import java.util.Map;
+
+import org.junit.Test;
+
+import com.google.common.collect.ImmutableSet;
+import com.google.common.collect.Lists;
+import com.mysema.query.annotations.QueryEntity;
+
+
+public class GroupBy4Test {
+
+    @QueryEntity
+    public static class Table {
+        String col1, col2, col3;
+
+        public Table(String c1, String c2, String c3) {
+            col1 = c1;
+            col2 = c2;
+            col3 = c3;
+        }
+    }
+
+    @Test
+    public void test() {
+        List<Table> data = Lists.newArrayList();
+        data.add(new Table("1", "abc", "111"));
+        data.add(new Table("1", "pqr", "222"));
+        data.add(new Table("2", "abc", "333"));
+        data.add(new Table("2", "pqr", "444"));
+        data.add(new Table("3", "abc", "555"));
+        data.add(new Table("3", "pqr", "666"));
+
+        QGroupBy4Test_Table table = QGroupBy4Test_Table.table;
+        Map<String, Map<String, String>> grouped = CollQueryFactory
+                .from(table, data)
+                .transform(groupBy(table.col1).as(map(table.col2, table.col3)));
+
+        assertEquals(3, grouped.size());
+        assertEquals(2, grouped.get("1").size());
+        assertEquals(ImmutableSet.of("abc", "pqr"),  grouped.get("1").keySet());
+
+    }
+
+}