From b414a3cb389715da3460f9b0c540b11f45829c0e Mon Sep 17 00:00:00 2001
From: Giles Knap <giles.knap@diamond.ac.uk>
Date: Fri, 17 May 2024 08:35:24 +0000
Subject: [PATCH] add strict mode to Jinja renders

---
 src/ibek/gen_scripts.py | 10 ++++++++--
 src/ibek/utils.py       |  4 ++--
 tests/test_unit.py      | 31 +++++++++++++++++++++++++++++++
 3 files changed, 41 insertions(+), 4 deletions(-)

diff --git a/src/ibek/gen_scripts.py b/src/ibek/gen_scripts.py
index 91dd69fb7..cffa98241 100644
--- a/src/ibek/gen_scripts.py
+++ b/src/ibek/gen_scripts.py
@@ -5,7 +5,7 @@
 import logging
 from typing import List, Sequence, Tuple
 
-from jinja2 import Template
+from jinja2 import StrictUndefined, Template
 
 from ibek.utils import UTILS
 
@@ -31,7 +31,13 @@ def create_db_script(
 
         templates = renderer.render_database(extra_databases)
 
-        return Template(jinja_txt).render(templates=templates)
+        try:
+            return Template(jinja_txt).render(
+                templates=templates, undefined=StrictUndefined
+            )
+        except Exception:
+            print(f"ERROR RENDERING DATABASE TEMPLATE:\n{templates}")
+            raise
 
 
 def create_boot_script(entities: Sequence[Entity]) -> str:
diff --git a/src/ibek/utils.py b/src/ibek/utils.py
index 8361287cd..dff8817dd 100644
--- a/src/ibek/utils.py
+++ b/src/ibek/utils.py
@@ -12,7 +12,7 @@
 from pathlib import Path
 from typing import Any, Dict, Mapping
 
-from jinja2 import Template
+from jinja2 import StrictUndefined, Template
 
 
 @dataclass
@@ -110,7 +110,7 @@ def render(self, context: Any, template_text: Any) -> str:
             return template_text
 
         try:
-            jinja_template = Template(template_text)
+            jinja_template = Template(template_text, undefined=StrictUndefined)
             return jinja_template.render(
                 context,
                 __utils__=self,
diff --git a/tests/test_unit.py b/tests/test_unit.py
index 2bbc5cc01..a5f978033 100644
--- a/tests/test_unit.py
+++ b/tests/test_unit.py
@@ -2,11 +2,17 @@
 Some unit tests for ibek.
 """
 
+import dataclasses
+
+import jinja2
+import pytest
+
 from ibek.args import IdArg, ObjectArg
 from ibek.commands import semver_compare
 from ibek.ioc import id_to_entity
 from ibek.ioc_factory import IocFactory
 from ibek.support import EntityDefinition, Support
+from ibek.utils import UTILS
 
 
 def test_object_references(entity_factory):
@@ -58,3 +64,28 @@ def test_compare():
     assert semver_compare("1.1.1", "==1.1.1")
     assert semver_compare("1.1.1", ">=1.1.0")
     assert not semver_compare("1.1.1", ">=1.1.2")
+
+
+@dataclasses.dataclass
+class Person:
+    name: str
+    age: int
+
+
+def test_strict():
+    """
+    validate that bad references in Jinja are caught
+    """
+    p = Person("giles", 59)
+
+    my_template = "{{ person.name ~ ' of age ' ~ person.age }}"
+    text = UTILS.render({"person": p}, my_template)
+    assert text == "giles of age 59"
+
+    my_template = "{{ person.name ~ ' of age ' ~ height }}"
+    with pytest.raises(jinja2.exceptions.UndefinedError):
+        text = UTILS.render({"person": p}, my_template)
+
+    my_template = "{{ person.name ~ ' of age ' ~ person.height }}"
+    with pytest.raises(jinja2.exceptions.UndefinedError):
+        text = UTILS.render({"person": p}, my_template)