From 783c287e51c1614cd8341ede263c914aad691449 Mon Sep 17 00:00:00 2001
From: Terry Cain <terry@terrys-home.co.uk>
Date: Mon, 18 Sep 2017 21:27:56 +0100
Subject: [PATCH] Added non existant parameter test + needed error responses

---
 moto/ssm/responses.py            |  6 +++++-
 tests/test_ssm/test_ssm_boto3.py | 15 +++++++++++++++
 2 files changed, 20 insertions(+), 1 deletion(-)

diff --git a/moto/ssm/responses.py b/moto/ssm/responses.py
index a2673f7e..ca033969 100644
--- a/moto/ssm/responses.py
+++ b/moto/ssm/responses.py
@@ -49,7 +49,11 @@ class SimpleSystemManagerResponse(BaseResponse):
         result = self.ssm_backend.get_parameter(name, with_decryption)
 
         if result is None:
-            return '', dict(status=400)
+            error = {
+                '__type': 'ParameterNotFound',
+                'message': 'Parameter {0} not found.'.format(name)
+            }
+            return json.dumps(error), dict(status=400)
 
         response = {
             'Parameter': {
diff --git a/tests/test_ssm/test_ssm_boto3.py b/tests/test_ssm/test_ssm_boto3.py
index 859ec7a8..2374ebf3 100644
--- a/tests/test_ssm/test_ssm_boto3.py
+++ b/tests/test_ssm/test_ssm_boto3.py
@@ -1,6 +1,7 @@
 from __future__ import unicode_literals
 
 import boto3
+import botocore.exceptions
 import sure   # noqa
 
 from moto import mock_ssm
@@ -85,6 +86,20 @@ def test_get_parameter():
     response['Parameter']['Type'].should.equal('String')
 
 
+@mock_ssm
+def test_get_nonexistant_parameter():
+    client = boto3.client('ssm', region_name='us-east-1')
+
+    try:
+        client.get_parameter(
+            Name='test_noexist',
+            WithDecryption=False)
+        raise RuntimeError('Should of failed')
+    except botocore.exceptions.ClientError as err:
+        err.operation_name.should.equal('GetParameter')
+        err.response['Error']['Message'].should.equal('Parameter test_noexist not found.')
+
+
 @mock_ssm
 def test_describe_parameters():
     client = boto3.client('ssm', region_name='us-east-1')