More dataset collection unit testing...

test/unit/data/dataset_collections/test_matching.py

@@ -17,14 +17,7 @@ def test_lists_of_same_cardinality_match():
 
 
 def test_nested_lists_match():
-    nested_list = list_instance(
-        elements=[
-            pair_element("data1"),
-            pair_element("data2"),
-            pair_element("data3"),
-        ],
-        collection_type="list:paired",
-    )
+    nested_list = list_paired_instance()
     assert_can_match(nested_list, nested_list)
 
 
@@ -86,6 +79,19 @@ def pair_element(element_identifier):
     return collection_element(element_identifier, pair_instance().collection)
 
 
+def list_element(element_identifier, list_collection=None):
+    return collection_element(element_identifier, list_collection or list_instance().collection)
+
+
+def list_of_lists_instance():
+    return list_instance(
+        elements=[
+            list_element("outer1"),
+            list_element("outer2"),
+        ]
+    )
+
+
 def pair_instance():
     paired_collection_instance = collection_instance(
         collection_type="paired",
@@ -97,6 +103,17 @@ def pair_instance():
     return paired_collection_instance
 
 
+def list_paired_instance():
+    return list_instance(
+        elements=[
+            pair_element("data1"),
+            pair_element("data2"),
+            pair_element("data3"),
+        ],
+        collection_type="list:paired",
+    )
+
+
 def list_instance(collection_type="list", elements=None, ids=None):
     if not elements:
         if ids is None:

test/unit/data/dataset_collections/test_structure.py

@@ -0,0 +1,43 @@
+from galaxy.model.dataset_collections.structure import get_structure
+from galaxy.model.dataset_collections.type_description import CollectionTypeDescriptionFactory
+from .test_matching import (
+    list_of_lists_instance,
+    list_paired_instance,
+    pair_instance,
+)
+
+factory = CollectionTypeDescriptionFactory(None)
+
+
+def test_get_structure_simple():
+    paired_type_description = factory.for_collection_type("paired")
+    tree = get_structure(pair_instance(), paired_type_description)
+    assert len(tree.children) == 2
+    assert tree.children[0][0] == "left"  # why not forward?
+    assert tree.children[0][1].is_leaf
+
+
+def test_get_structure_list_paired_over_paired():
+    paired_type_description = factory.for_collection_type("list:paired")
+    tree = get_structure(list_paired_instance(), paired_type_description, "paired")
+    assert tree.collection_type_description.collection_type == "list"
+    assert len(tree.children) == 3
+    assert tree.children[0][0] == "data1"
+    assert tree.children[0][1].is_leaf
+
+def test_get_structure_list_of_lists():
+    list_of_lists_type_description = factory.for_collection_type("list:list")
+    tree = get_structure(list_of_lists_instance(), list_of_lists_type_description)
+    assert tree.collection_type_description.collection_type == "list:list"
+    assert len(tree.children) == 2
+    assert tree.children[0][0] == "outer1"
+    assert not tree.children[0][1].is_leaf
+
+
+def test_get_structure_list_of_lists_over_list():
+    list_of_lists_type_description = factory.for_collection_type("list:list")
+    tree = get_structure(list_of_lists_instance(), list_of_lists_type_description, "list")
+    assert tree.collection_type_description.collection_type == "list"
+    assert len(tree.children) == 2
+    assert tree.children[0][0] == "outer1"
+    assert tree.children[0][1].is_leaf