Fix to_date and to_date_time conversion index error

Author: ir4y

fhirpathpy/engine/invocations/misc.py

@@ -129,54 +129,53 @@ def to_string(ctx, coll):
 
 def to_date_time(ctx, coll):
     ln = len(coll)
-    rtn = []
     if ln > 1:
         raise Exception("to_date_time called for a collection of length " + str(ln))
 
-    if ln == 1:
-        value = util.get_data(coll[0])
+    if ln != 1:
+        return []
 
-        dateTimeObject = nodes.FP_DateTime(value)
+    value = util.get_data(coll[0])
+    dateTimeObject = nodes.FP_DateTime(value)
 
-        if dateTimeObject:
-            rtn.append(dateTimeObject)
+    if not dateTimeObject:
+        return []
 
-    return util.get_data(rtn[0])
+    return util.get_data(dateTimeObject)
 
 
 def to_time(ctx, coll):
     ln = len(coll)
-    rtn = []
     if ln > 1:
         raise Exception("to_time called for a collection of length " + str(ln))
 
-    if ln == 1:
-        value = util.get_data(coll[0])
+    if ln != 1:
+        return []
 
-        timeObject = nodes.FP_Time(value)
+    value = util.get_data(coll[0])
+    timeObject = nodes.FP_Time(value)
 
-        if timeObject:
-            rtn.append(timeObject)
+    if not timeObject:
+        return []
 
-    return util.get_data(rtn[0])
+    return util.get_data(timeObject)
 
 
 def to_date(ctx, coll):
     ln = len(coll)
-    rtn = []
-
     if ln > 1:
         raise Exception("to_date called for a collection of length " + str(ln))
 
-    if ln == 1:
-        value = util.get_data(coll[0])
+    if ln != 1:
+        return []
 
-        dateObject = nodes.FP_DateTime(value)
+    value = util.get_data(coll[0])
+    dateObject = nodes.FP_DateTime(value)
 
-        if dateObject:
-            rtn.append(dateObject)
+    if not dateObject:
+        return []
 
-    return util.get_data(rtn[0])
+    return util.get_data(dateObject)
 
 
 def create_converts_to_fn(to_function, _type):

tests/test_real.py

@@ -1,8 +1,8 @@
 import pickle
+import pytest
 
 from fhirpathpy import compile, evaluate
 
-
 def find_concept_test():
     env = {}
     env["Source"] = {
@@ -190,3 +190,30 @@ def compile_with_user_defined_table_test():
         options={"userInvocationTable": user_invocation_table},
     )
     assert expr({"a": [5, 6, 7]}) == [5 * 5, 6 * 6, 7 * 7]
+
+
+def age_comparation_test():
+    assert evaluate(
+        {"resourceType": "Patient", "birthDate": "2024-08-01"},
+        "Patient.birthDate + 12 month <= now()",
+    ) == [True]
+
+@pytest.mark.parametrize(
+    ("effective", "result"),
+    [
+        (None, []),
+        ({}, []),
+        ("2020", ["2020"]),
+        ("2020-01-01", ["2020-01-01"])
+    ],
+)
+def emty_substring_test(effective, result):
+    if(isinstance(effective, str)):
+        effective = {"effective": effective}
+    r = evaluate(effective, "effective.toString().substring(0,10).toDate()")
+    if len(r) > 0:
+        assert len(r) == len(result)
+        for index,item in enumerate(r):
+            assert str(item) == result[index]
+    else:
+        assert r == result