Error handling: Model-level validations, proper error responses.

tests/test_ec2/test_instances.py

@@ -4,6 +4,7 @@ import boto
 from boto.ec2.instance import Reservation, InstanceAttribute
 from boto.exception import EC2ResponseError
 import sure  # noqa
+from nose.tools import assert_raises
 
 from moto import mock_ec2
 
@@ -72,10 +73,11 @@ def test_get_instances_by_id():
     instance_ids.should.equal([instance1.id, instance2.id])
 
     # Call get_all_instances with a bad id should raise an error
-    conn.get_all_instances.when.called_with(instance_ids=[instance1.id, "i-1234abcd"]).should.throw(
-        EC2ResponseError,
-        "The instance ID 'i-1234abcd' does not exist"
-    )
+    with assert_raises(EC2ResponseError) as cm:
+        conn.get_all_instances(instance_ids=[instance1.id, "i-1234abcd"])
+    cm.exception.code.should.equal('InvalidInstanceID.NotFound')
+    cm.exception.status.should.equal(400)
+    cm.exception.request_id.should_not.be.none
 
 
 @mock_ec2