add new hook for Jinja2 extensions

README.md

@@ -24,7 +24,7 @@ Features:
 * Jinja2 templating
 * INI, YAML, JSON data sources supported
 * Environment variables can be used with or without data files
-* Plugins can provide additional formats, filters, tests, and global
+* Plugins can provide additional formats, filters, tests, extensions and global
   functions (see
   [jinjanator-plugins](https://github.com/kpfleming/jinjanator-plugins)
   for details)

src/jinjanator/cli.py

@@ -84,6 +84,10 @@ def __init__(
         for plugin_tests in plugin_hook_callers.plugin_tests():
             self._env.tests.update(plugin_tests)
 
+        for plugin_extensions in plugin_hook_callers.plugin_extensions():
+            for extension in plugin_extensions:
+                self._env.add_extension(extension)
+
     def render(self, template_name: str, context: Mapping[str, str]) -> str:
         return self._env.get_template(template_name).render(context)