Avoid trying to pass revision unless provided by user in app refresh

Fixes #955

This also implements functionality that allows passing resources
argument to application refresh.

Author: cderici

juju/application.py

@@ -736,6 +736,25 @@ async def refresh(
             err = charm_origin_result.error
             raise JujuError(f'{err.code} : {err.message}')
 
+<<<<<<< HEAD
+=======
+        # Now take care of the resources:
+
+        # user supplied resources to be used in refresh,
+        # will override the default values if there's any
+        arg_resources = resources or {}
+
+        # need to process the given resources, as they can be
+        # paths or revisions
+        _arg_res_filenames = {}
+        _arg_res_revisions = {}
+        for res, filename_or_rev in arg_resources.items():
+            if isinstance(filename_or_rev, int):
+                _arg_res_revisions[res] = filename_or_rev
+            else:
+                _arg_res_filenames[res] = filename_or_rev
+
+>>>>>>> 5fbf5bc (Avoid trying to pass revision unless provided by user in app refresh)
         # Already prepped the charm_resources
         # Now get the existing resources from the ResourcesFacade
         request_data = [client.Entity(self.tag)]
@@ -749,23 +768,27 @@ async def refresh(
         # Compute the difference btw resources needed and the existing resources
         resources_to_update = []
         for resource in charm_resources:
-            if utils.should_upgrade_resource(resource, existing_resources):
+            if utils.should_upgrade_resource(resource, existing_resources, arg_resources):
                 resources_to_update.append(resource)
 
         # Update the resources
         if resources_to_update:
             request_data = []
             for resource in resources_to_update:
+                res_name = resource.get('Name', resource.get('name'))
                 request_data.append(client.CharmResource(
                     description=resource.get('Description', resource.get('description')),
-                    fingerprint=resource.get('Fingerprint', resource.get('fingerprint')),
-                    name=resource.get('Name', resource.get('name')),
-                    path=resource.get('Path', resource.get('filename')),
-                    revision=resource.get('Revision', resource.get('revision', -1)),
-                    size=resource.get('Size', resource.get('size')),
+                    fingerprint=resource.get('Fingerprint', resource.get('fingerprint', [])),
+                    name=res_name,
+                    path=_arg_res_filenames.get(res_name,
+                                                resource.get('Path',
+                                                             resource.get('filename', ''))),
+                    revision=_arg_res_revisions.get(res_name, -1),
+                    size=resource.get('Size', resource.get('size', 0)),
                     type_=resource.get('Type', resource.get('type')),
                     origin='store',
                 ))
+
             response = await resources_facade.AddPendingResources(
                 application_tag=self.tag,
                 charm_url=charm_url,

juju/utils.py

@@ -532,20 +532,25 @@ def series_selector(series_arg='', charm_url=None, model_config=None, supported_
     return DEFAULT_SUPPORTED_LTS
 
 
-def should_upgrade_resource(available_resource, existing_resources):
+def should_upgrade_resource(available_resource, existing_resources, arg_resources):
     """Called in the context of upgrade_charm. Given a resource R, takes a look at the resources we
     already have and decides if we need to refresh R.
 
     :param dict[str] available_resource: The dict representing the client.Resource coming from the
     charmhub api. We're considering if we need to refresh this during upgrade_charm.
     :param dict[str] existing_resources: The dict coming from resources_facade.ListResources
     representing the resources of the currently deployed charm.
+    :param dict[str] arg_resources: user provided resources to be refreshed
 
     :result bool: The decision to refresh the given resource
     """
+
     # should upgrade resource?
     res_name = available_resource.get('Name', available_resource.get('name'))
 
+    if res_name in arg_resources:
+        return True
+
     # do we have it already?
     if res_name in existing_resources:
         # no upgrade, if it's upload