Merge "Split revert/execute missing args messages"

2 files changed, 17 insertions, 10 deletions

diff --git a/taskflow/engines/action_engine/engine.py b/taskflow/engines/action_engine/engine.py
index aea4b1f..67c3ead 100644
--- a/taskflow/engines/action_engine/engine.py
+++ b/taskflow/engines/action_engine/engine.py
@@ -408,15 +408,18 @@ class ActionEngine(base.Engine):
             revert_missing = self.storage.fetch_unsatisfied_args(
                 atom.name, atom.revert_rebind,
                 optional_args=atom.revert_optional)
-            atom_missing = exec_missing.union(revert_missing)
-            if atom_missing:
-                cause = exc.MissingDependencies(atom,
-                                                sorted(atom_missing),
-                                                cause=last_cause)
-                last_cause = cause
-                last_node = atom
-                missing_nodes += 1
-                missing.update(atom_missing)
+            atom_missing = (('execute', exec_missing),
+                            ('revert', revert_missing))
+            for method, method_missing in atom_missing:
+                if method_missing:
+                    cause = exc.MissingDependencies(atom,
+                                                    sorted(method_missing),
+                                                    cause=last_cause,
+                                                    method=method)
+                    last_cause = cause
+                    last_node = atom
+                    missing_nodes += 1
+                    missing.update(method_missing)
         if missing:
             # For when a task is provided (instead of a flow) and that
             # task is the only item in the graph and its missing deps, avoid
diff --git a/taskflow/exceptions.py b/taskflow/exceptions.py
index beb66e9..c21f7fb 100644
--- a/taskflow/exceptions.py
+++ b/taskflow/exceptions.py
@@ -187,8 +187,12 @@ class MissingDependencies(DependencyFailure):
     MESSAGE_TPL = ("'%(who)s' requires %(requirements)s but no other entity"
                    " produces said requirements")
 
-    def __init__(self, who, requirements, cause=None):
+    METHOD_TPL = "'%(method)s' method on "
+
+    def __init__(self, who, requirements, cause=None, method=None):
         message = self.MESSAGE_TPL % {'who': who, 'requirements': requirements}
+        if method:
+            message = (self.METHOD_TPL % {'method': method}) + message
         super(MissingDependencies, self).__init__(message, cause=cause)
         self.missing_requirements = requirements