Normalize preloaded template loader names to support dot-prefixed partials

Author: servletcloud

src/fstache/_factories.py

@@ -283,6 +283,18 @@ def load_template(name: str) -> CompiledTemplate:
         if template is not None:
             return template
 
+        normalized = _normalize_template_name(
+            name,
+            extension=extension,
+            remove_extension=remove_extension,
+        )
+        if normalized is not None and normalized != name:
+            template = templates.get(normalized)
+            if template is not None:
+                templates[name] = template
+
+                return template
+
         return resolve_missing_template(name)
 
     return load_template
@@ -337,6 +349,27 @@ def _template_path_for_name(
     extension: str,
     remove_extension: bool,
 ) -> Path | None:
+    normalized = _normalize_template_name(
+        name,
+        extension=extension,
+        remove_extension=remove_extension,
+    )
+
+    if normalized is None:
+        return None
+
+    if remove_extension and extension != "":
+        return root / f"{normalized}{extension}"
+
+    return root / normalized
+
+
+def _normalize_template_name(
+    name: str,
+    *,
+    extension: str,
+    remove_extension: bool,
+) -> str | None:
     if remove_extension and extension != "":
         path = Path(f"{name}{extension}")
     else:
@@ -347,7 +380,12 @@ def _template_path_for_name(
     if path.is_absolute() or ".." in path.parts:
         return None
 
-    return root / path
+    name_with_ext = path.as_posix()
+    if remove_extension and extension != "":
+        if name_with_ext.endswith(extension):
+            return name_with_ext[: -len(extension)]
+
+    return name_with_ext
 
 
 def _iter_template_sources(

tests/test_factories.py

@@ -298,6 +298,27 @@ def test_preload_templates_true_does_not_see_root_template_edits(
 
         assert render("page.mustache", {"name": "Ada"}).to_bytes() == b"Hello Ada"
 
+    def test_preloaded_and_live_renderers_resolve_dot_prefixed_partials_equally(
+        self,
+        tmp_path: Path,
+    ) -> None:
+        _write_template(tmp_path / "page.mustache", b"Hello {{>./partial.mustache}}")
+        _write_template(tmp_path / "partial.mustache", b"Partial")
+
+        def create(preload_templates: bool) -> fstache.TemplateRenderer:
+            return fstache.create_renderer(
+                tmp_path,
+                preload_templates=preload_templates,
+                resolve_missing_template=fstache.resolve_missing_template_as_empty,
+            )
+
+        live = create(preload_templates=False)
+        preloaded = create(preload_templates=True)
+        expected = live("page.mustache", {}).to_bytes()
+
+        assert expected == b"Hello Partial"
+        assert preloaded("page.mustache", {}).to_bytes() == expected
+
     def test_preload_templates_false_sees_partial_template_edits(
         self,
         tmp_path: Path,