Allow testing element counts in tool output collections.

lib/galaxy/tools/parser/interface.py

@@ -347,10 +347,11 @@ class TestCollectionDef( object ):
 
 
 class TestCollectionOutputDef( object ):
-    # TODO: do not require XML directly here.
 
     def __init__( self, name, attrib, element_tests ):
         self.name = name
         self.collection_type = attrib.get( "type", None )
+        count = attrib.get("count", None)
+        self.count = int(count) if count is not None else None
         self.attrib = attrib
         self.element_tests = element_tests

test/functional/test_toolbox.py

@@ -213,6 +213,14 @@ class ToolTestCase( TwillTestCase ):
                         message = template % (name, expected_collection_type, collection_type)
                         raise AssertionError(message)
 
+                expected_element_count = output_collection_def.count
+                if expected_element_count:
+                    actual_element_count = len(data_collection[ "elements" ])
+                    if expected_element_count != actual_element_count:
+                        template = "Expected output collection [%s] to have %s elements, but it had %s."
+                        message = template % (name, expected_element_count, actual_element_count)
+                        raise AssertionError(message)
+
                 def verify_elements( element_objects, element_tests ):
                     for element_identifier, ( element_outfile, element_attrib ) in element_tests.items():
                         element = get_element( element_objects, element_identifier )

test/functional/tools/collection_creates_list.xml

@@ -22,7 +22,7 @@
           <element name="l12" value="simple_line.txt" />
         </collection>
       </param>
-      <output_collection name="list_output" type="list">
+      <output_collection name="list_output" type="list" count="2">
         <element name="l11">
           <assert_contents>
             <has_text_matching expression="^identifier is l11\n$" />