WIP: partial fix for #15 (NOTE: needs further testing and emrobustening)

emrichen/tags/lookup.py

@@ -7,13 +7,31 @@
 from .base import BaseTag
 
 
+class EnrichingProxy:
+    """
+    Eager JSONPath lookups and Emrichen's lazy evaluation don't always mix well.
+    Deep nesting with !Var etc. may cause a situation where we try to !Lookup or
+    !Format on a structure that is not yet enriched.
+
+    This tries to fix that by enriching property access.
+
+    https://github.com/con2/emrichen/issues/15
+    """
+    def __init__(self, obj, context):
+        self.obj = obj
+        self.context = context
+
+    def __getitem__(self, index):
+        return self.context.enrich(self.obj[index])
+
+
 @lru_cache()
 def parse_jsonpath(expr: str):
     return jsonpath_rw.parse(expr)
 
 
 def find_jsonpath_in_context(jsonpath_str: str, context: Context) -> List[jsonpath_rw.DatumInContext]:
-    return parse_jsonpath(jsonpath_str).find(context)
+    return parse_jsonpath(jsonpath_str).find(EnrichingProxy(context, context))
 
 
 class Lookup(BaseTag):

tests/test_lookup.py

@@ -68,7 +68,6 @@ def test_lookup_no_match():
     assert 'no matches for' in str(ei.value)
 
 
-@pytest.mark.xfail
 def test_late_enrich():
     template = Template.parse('''
 !Defaults
@@ -98,3 +97,17 @@ def test_lookup_enrich():
   template: !Var item
 ''')
     assert template.enrich({}) == [{'should_contain_5': [5]}]
+
+
+@pytest.mark.xfail
+def test_recursive_data_structure():
+    template = Template.parse('''
+!Defaults
+x:
+    y: 5
+    x: !Var x
+---
+five: !Lookup x.y
+also_five: !Lookup x.x.x.x.x.y
+''')
+    assert template.enrich({}) == [{'five': 5, 'also_five': 5}]