Improve ResourceError messages by including the resource/group/member names.

Author: thet

CHANGES.rst

@@ -4,6 +4,9 @@ Changelog
 1.3 (unreleased)
 ----------------
 
+- Improve ResourceError messages by including the resource/group/member names.
+  [thet]
+
 - Do not wrap resource ``__repr__`` output in ``<>`` to render tracebacks
   properly in browser.
   [lenadax]

webresource/_api.py

@@ -85,7 +85,10 @@ def include(self, include):
     def remove(self):
         """Remove resource or resource group from parent group."""
         if not self.parent:
-            raise ResourceError('Object is no member of a resource group')
+            raise ResourceError(
+                'Cannot remove resource or resource group "{}".'
+                ' It is no member of a resource group'.format(self.name)
+            )
         self.parent.members.remove(self)
         self.parent = None
 
@@ -136,7 +139,10 @@ def __init__(
         :raise ResourceError: No resource and no url given.
         """
         if resource is None and url is None:
-            raise ResourceError('Either resource or url must be given')
+            raise ResourceError(
+                'Either resource or url must be given for resource '
+                '"{}"'.format(name)
+            )
         super(Resource, self).__init__(
             name=name, directory=directory, path=path,
             include=include, group=group
@@ -169,7 +175,9 @@ def file_path(self):
         """Absolute resource file path depending on operation mode."""
         directory = self.directory
         if not directory:
-            raise ResourceError('No directory set on resource.')
+            raise ResourceError(
+                'No directory set on resource "{}".'.format(self.name)
+            )
         return os.path.join(directory, self.file_name)
 
     @property
@@ -323,8 +331,10 @@ def integrity(self):
     def integrity(self, integrity):
         if integrity is True:
             if self.url is not None:
-                msg = 'Cannot calculate integrity hash from external resource'
-                raise ResourceError(msg)
+                raise ResourceError(
+                    'Cannot calculate integrity hash from external resource '
+                    '"{}"'.format(self.name)
+                )
             self._integrity_hash = None
         else:
             self._integrity_hash = integrity
@@ -564,8 +574,10 @@ def add(self, member):
         """
         if not isinstance(member, (ResourceGroup, Resource)):
             raise ResourceError(
-                'Resource group can only contain instances '
-                'of ``ResourceGroup`` or ``Resource``'
+                'Resource group "{}" can only contain instances '
+                'of ``ResourceGroup`` or ``Resource`` (member: "{}")'.format(
+                    self.name, member.name
+                )
             )
         member.parent = self
         self._members.append(member)