Add invalid subnet test.

tests/test_redshift/test_redshift.py

@@ -6,6 +6,7 @@ from boto.redshift.exceptions import (
     ClusterParameterGroupNotFound,
     ClusterSecurityGroupNotFound,
     ClusterSubnetGroupNotFound,
+    InvalidSubnet,
 )
 import sure  # noqa
 
@@ -305,6 +306,17 @@ def test_create_cluster_subnet_group():
     set(subnet_ids).should.equal(set([subnet1.id, subnet2.id]))
 
 
+@mock_redshift
+@mock_ec2
+def test_create_invalid_cluster_subnet_group():
+    redshift_conn = boto.connect_redshift()
+    redshift_conn.create_cluster_subnet_group.when.called_with(
+        "my_subnet",
+        "This is my subnet group",
+        subnet_ids=["subnet-1234"],
+    ).should.throw(InvalidSubnet)
+
+
 @mock_redshift
 def test_describe_non_existant_subnet_group():
     conn = boto.redshift.connect_to_region("us-east-1")