fix TargetGroupNnotFoundError is not definied correctly (#1099)

moto/elbv2/exceptions.py

@@ -42,7 +42,7 @@ class SubnetNotFoundError(ELBClientError):
 class TargetGroupNotFoundError(ELBClientError):
 
     def __init__(self):
-        super(TooManyTagsError, self).__init__(
+        super(TargetGroupNotFoundError, self).__init__(
             "TargetGroupNotFound",
             "The specified target group does not exist.")
 

tests/test_elbv2/test_elbv2.py

@@ -861,3 +861,43 @@ def test_handle_listener_rules():
                 'Type': 'forward'
             }]
         )
+
+
+@mock_elbv2
+@mock_ec2
+def test_describe_invalid_target_group():
+    conn = boto3.client('elbv2', region_name='us-east-1')
+    ec2 = boto3.resource('ec2', region_name='us-east-1')
+
+    security_group = ec2.create_security_group(GroupName='a-security-group', Description='First One')
+    vpc = ec2.create_vpc(CidrBlock='172.28.7.0/24', InstanceTenancy='default')
+    subnet1 = ec2.create_subnet(VpcId=vpc.id, CidrBlock='172.28.7.192/26', AvailabilityZone='us-east-1a')
+    subnet2 = ec2.create_subnet(VpcId=vpc.id, CidrBlock='172.28.7.192/26', AvailabilityZone='us-east-1b')
+
+    response = conn.create_load_balancer(
+        Name='my-lb',
+        Subnets=[subnet1.id, subnet2.id],
+        SecurityGroups=[security_group.id],
+        Scheme='internal',
+        Tags=[{'Key': 'key_name', 'Value': 'a_value'}])
+
+    load_balancer_arn = response.get('LoadBalancers')[0].get('LoadBalancerArn')
+
+    response = conn.create_target_group(
+        Name='a-target',
+        Protocol='HTTP',
+        Port=8080,
+        VpcId=vpc.id,
+        HealthCheckProtocol='HTTP',
+        HealthCheckPort='8080',
+        HealthCheckPath='/',
+        HealthCheckIntervalSeconds=5,
+        HealthCheckTimeoutSeconds=5,
+        HealthyThresholdCount=5,
+        UnhealthyThresholdCount=2,
+        Matcher={'HttpCode': '200'})
+    target_group = response.get('TargetGroups')[0]
+
+    # Check error raises correctly
+    with assert_raises(ClientError):
+        conn.describe_target_groups(Names=['invalid'])