Added Union as root term

Author: dancannon

CHANGELOG.md

@@ -7,6 +7,7 @@ This project adheres to [Semantic Versioning](http://semver.org/).
  - Added race detector to CI
  - Replaced `UseOutdated` with `ReadMode`
  - Added `EmergencyRepair` and `NonVotingReplicaTags` to `ReconfigureOpts`
+ - Added `Union` as a root term
 
 ## Deprecated
  - Deprecated `UseOutdated` optional argument

query_transformation.go

@@ -151,6 +151,11 @@ func (t Term) IsEmpty(args ...interface{}) Term {
 	return constructMethodTerm(t, "IsEmpty", p.Term_IS_EMPTY, args, map[string]interface{}{})
 }
 
+// Union concatenates two sequences.
+func Union(args ...interface{}) Term {
+	return constructRootTerm("Union", p.Term_UNION, args, map[string]interface{}{})
+}
+
 // Union concatenates two sequences.
 func (t Term) Union(args ...interface{}) Term {
 	return constructMethodTerm(t, "Union", p.Term_UNION, args, map[string]interface{}{})

query_transformation_test.go

@@ -426,3 +426,16 @@ func (s *RethinkSuite) TestTransformationUnion(c *test.C) {
 	c.Assert(err, test.IsNil)
 	c.Assert(response, jsonEquals, []interface{}{1, 2, 3, 4, 5, 6, 7, 8, 9, 1, 2, 3, 4, 5, 6, 7, 8, 9})
 }
+
+func (s *RethinkSuite) TestTransformationUnionRoot(c *test.C) {
+	query := Union(arr, arr)
+
+	var response []interface{}
+	res, err := query.Run(session)
+	c.Assert(err, test.IsNil)
+
+	err = res.All(&response)
+
+	c.Assert(err, test.IsNil)
+	c.Assert(response, jsonEquals, []interface{}{1, 2, 3, 4, 5, 6, 7, 8, 9, 1, 2, 3, 4, 5, 6, 7, 8, 9})
+}