Minor RDS Clean up (#3682)

* Fix `DBInstanceNotFound` error message

Changed from `Database` to `DBInstance`, which is actually what comes back from AWS.

* Remove duplicate test

The removed test actually fails if run in isolation because `rds2` is not a
valid boto3 client service.  The reason this test never caused CI to fail is
because it is redefined later in the test suite, effectively making it dead
code that will never run.

Duplicate test has been removed and the remaining test has been improved
with more explicit asserts.

moto/rds2/exceptions.py

@@ -24,7 +24,8 @@ class RDSClientError(BadRequest):
 class DBInstanceNotFoundError(RDSClientError):
     def __init__(self, database_identifier):
         super(DBInstanceNotFoundError, self).__init__(
-            "DBInstanceNotFound", "Database {0} not found.".format(database_identifier)
+            "DBInstanceNotFound",
+            "DBInstance {0} not found.".format(database_identifier),
         )
 
 

tests/test_rds2/test_filters.py

@@ -127,7 +127,7 @@ class TestDBInstanceFilters(object):
             )
         ex.value.response["Error"]["Code"].should.equal("DBInstanceNotFound")
         ex.value.response["Error"]["Message"].should.equal(
-            "Database non-existent not found."
+            "DBInstance non-existent not found."
         )
 
     def test_valid_db_instance_identifier_with_exclusive_filter(self):
@@ -172,7 +172,7 @@ class TestDBInstanceFilters(object):
             )
         ex.value.response["Error"]["Code"].should.equal("DBInstanceNotFound")
         ex.value.response["Error"]["Message"].should.equal(
-            "Database db-instance-0 not found."
+            "DBInstance db-instance-0 not found."
         )
 
 

tests/test_rds2/test_rds2.py

@@ -2,6 +2,7 @@ from __future__ import unicode_literals
 
 from botocore.exceptions import ClientError
 import boto3
+import pytest
 import sure  # noqa
 from moto import mock_ec2, mock_kms, mock_rds2
 from moto.core import ACCOUNT_ID
@@ -471,14 +472,6 @@ def test_delete_database():
     snapshots[0].get("Engine").should.equal("postgres")
 
 
-@mock_rds2
-def test_delete_non_existent_database():
-    conn = boto3.client("rds2", region_name="us-west-2")
-    conn.delete_db_instance.when.called_with(
-        DBInstanceIdentifier="not-a-db"
-    ).should.throw(ClientError)
-
-
 @mock_rds2
 def test_create_db_snapshots():
     conn = boto3.client("rds", region_name="us-west-2")
@@ -793,9 +786,12 @@ def test_modify_non_existent_option_group():
 @mock_rds2
 def test_delete_non_existent_database():
     conn = boto3.client("rds", region_name="us-west-2")
-    conn.delete_db_instance.when.called_with(
-        DBInstanceIdentifier="not-a-db"
-    ).should.throw(ClientError)
+    with pytest.raises(ClientError) as ex:
+        conn.delete_db_instance(DBInstanceIdentifier="non-existent")
+    ex.value.response["Error"]["Code"].should.equal("DBInstanceNotFound")
+    ex.value.response["Error"]["Message"].should.equal(
+        "DBInstance non-existent not found."
+    )
 
 
 @mock_rds2