Merge pull request #143 from joguSD/pagination

Request Retrieval: Pagination

awsshell/wizard.py

@@ -250,16 +250,25 @@ def _handle_request_retrieval(self):
         req = self.retrieval['Resource']
         # get client from wizard's cache
         client = self._cached_creator.create_client(req['Service'])
-        # get the operation from the client
-        operation = getattr(client, xform_name(req['Operation']))
+        operation_name = xform_name(req['Operation'])
         # get any parameters
         parameters = req.get('Parameters', {})
         env_parameters = \
             self._env.resolve_parameters(req.get('EnvParameters', {}))
-        # union of parameters and env_parameters, conflicts favor env_params
+        # union of parameters and env_parameters, conflicts favor env params
         parameters = dict(parameters, **env_parameters)
-        # execute operation passing all parameters
-        return operation(**parameters)
+        # if the operation supports pagination, load all results upfront
+        if client.can_paginate(operation_name):
+            # get paginator and create iterator
+            paginator = client.get_paginator(operation_name)
+            page_iterator = paginator.paginate(**parameters)
+            # scroll through all pages combining them
+            return page_iterator.build_full_result()
+        else:
+            # get the operation from the client
+            operation = getattr(client, operation_name)
+            # execute operation passing all parameters
+            return operation(**parameters)
 
     def _handle_retrieval(self):
         # In case of no retrieval, empty dict

tests/unit/test_wizard.py

@@ -1,5 +1,6 @@
 import mock
 import pytest
+from botocore.session import Session
 from awsshell.utils import FileReadError
 from awsshell.wizard import stage_error_handler
 from awsshell.interaction import InteractionException
@@ -138,7 +139,8 @@ def test_static_retrieval_with_query(wizard_spec, loader):
 
 def test_request_retrieval(wizard_spec_request):
     # Tests that retrieval requests are parsed and call the correct operation
-    mock_session = mock.Mock()
+    mock_session = mock.Mock(spec=Session)
+    mock_session.create_client.return_value.can_paginate.return_value = False
     mock_request = mock_session.create_client.return_value.create_rest_api
     mock_request.return_value = {'id': 'api id', 'name': 'random name'}
 
@@ -148,6 +150,23 @@ def test_request_retrieval(wizard_spec_request):
     mock_request.assert_called_once_with(param='value', name='new api name')
 
 
+def test_request_retrieval_paginate(wizard_spec_request):
+    # Tests that retrieval requests are parsed and call the correct operation
+    mock_session = mock.Mock(spec=Session)
+    mock_client = mock_session.create_client.return_value
+    mock_client.can_paginate.return_value = True
+    mock_paginator = mock_client.get_paginator.return_value
+    mock_iterator = mock_paginator.paginate.return_value
+    result = {'id': 'api id', 'name': 'random name'}
+    mock_iterator.build_full_result.return_value = result
+    paginate = mock_paginator.paginate
+
+    loader = WizardLoader(mock_session)
+    wizard = loader.create_wizard(wizard_spec_request)
+    wizard.execute()
+    paginate.assert_called_once_with(param='value', name='new api name')
+
+
 def test_next_stage_resolution(wizard_spec, loader):
     # Test that the stage can resolve the next stage from env
     wizard_spec['Stages'][0]['Retrieval']['Path'] = '[0]'