Fixes #3063. Stopped directly accessing dict keys to avoid KeyError

exception and provide sane default values.  Normalised representation
keys provided as strings types to be returned as list types.

Author: nzlosh

st2common/st2common/util/actionalias_matching.py

@@ -39,16 +39,20 @@ def list_format_strings_from_aliases(aliases):
     for alias in aliases:
         for format_ in alias.formats:
             display, representations = normalise_alias_format_string(format_)
-            patterns.extend([(display, representation) for representation in representations])
+            if display and len(representations) == 0:
+                patterns.extend([(display, [])])
+            else:
+                patterns.extend([(display, representation) for representation in representations])
     return patterns
 
 
 def normalise_alias_format_string(alias_format):
     '''
-    StackStorm action aliases can have two types;
-        1. A simple string holding the format
-        2. A dictionary which hold numerous alias format "representation(s)"
-           With a single "display" for help about the action alias.
+    StackStorm action aliases come in two forms;
+        1. A string holding the format, which is also used as the help string.
+        2. A dictionary containing "display" and/or "representation" keys.
+           "representation": a list of numerous alias format "representation(s)"
+           "display": a help string to be displayed.
     This function processes both forms and returns a standardized form.
 
     :param alias_format: The alias format
@@ -64,8 +68,10 @@ def normalise_alias_format_string(alias_format):
         display = alias_format
         representation.append(alias_format)
     elif isinstance(alias_format, dict):
-        display = alias_format['display']
-        representation = alias_format['representation']
+        display = alias_format.get('display')
+        representation = alias_format.get('representation') or []
+        if isinstance(representation, six.string_types):
+            representation = [representation]
     else:
         raise TypeError("alias_format '%s' is neither a dictionary or string type."
                         % repr(alias_format))

st2common/tests/unit/test_util_actionalias_matching.py

@@ -65,6 +65,34 @@ def test_list_format_strings_from_aliases_with_display(self, mock):
         self.assertEqual(result[2][0], "How do I feel? I feel... {{status}}!")
         self.assertEqual(result[2][1], "How do I feel? I feel... {{status}}!")
 
+    def test_list_format_strings_from_aliases_with_display_only(self, mock):
+        ALIASES = [
+            MemoryActionAliasDB(name='andy', ref='the_goonies.1', formats=[
+                                {'display': 'Watch this.'}]),
+            MemoryActionAliasDB(name='andy', ref='the_goonies.2', formats=[
+                                {'display': "He's just like his {{relation}}."}])
+        ]
+        result = matching.list_format_strings_from_aliases(ALIASES)
+        self.assertEqual(len(result), 2)
+        self.assertEqual(result[0][0], 'Watch this.')
+        self.assertEqual(result[0][1], [])
+        self.assertEqual(result[1][0], "He's just like his {{relation}}.")
+        self.assertEqual(result[1][1], [])
+
+    def test_list_format_strings_from_aliases_with_representation_only(self, mock):
+        ALIASES = [
+            MemoryActionAliasDB(name='data', ref='the_goonies.1', formats=[
+                            {'representation': "That's okay daddy. You can't hug a {{object}}."}]),
+            MemoryActionAliasDB(name='mr_wang',  ref='the_goonies.2', formats=[
+                            {'representation': 'You are my greatest invention.'}])
+        ]
+        result = matching.list_format_strings_from_aliases(ALIASES)
+        self.assertEqual(len(result), 2)
+        self.assertEqual(result[0][0], None)
+        self.assertEqual(result[0][1], "That's okay daddy. You can't hug a {{object}}.")
+        self.assertEqual(result[1][0], None)
+        self.assertEqual(result[1][1], 'You are my greatest invention.')
+
     def test_normalise_alias_format_string(self, mock):
         result = matching.normalise_alias_format_string(
             'Quite an experience to live in fear, isn\'t it?')