Refactor template engine: Extract raise_no_default() into helper module (#152661)

Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>

homeassistant/helpers/template/__init__.py

@@ -82,6 +82,7 @@ from .context import (
     template_context_manager,
     template_cv,
 )
+from .helpers import raise_no_default
 from .render_info import RenderInfo, render_info_cv
 
 if TYPE_CHECKING:
@@ -1818,15 +1819,6 @@ def utcnow(hass: HomeAssistant) -> datetime:
     return dt_util.utcnow()
 
 
-def raise_no_default(function: str, value: Any) -> NoReturn:
-    """Log warning if no default is specified."""
-    template, action = template_cv.get() or ("", "rendering or compiling")
-    raise ValueError(
-        f"Template error: {function} got invalid input '{value}' when {action} template"
-        f" '{template}' but no default was specified"
-    )
-
-
 def forgiving_round(value, precision=0, method="common", default=_SENTINEL):
     """Filter to round a value."""
     try:

homeassistant/helpers/template/extensions/math.py

@@ -6,12 +6,12 @@ from collections.abc import Iterable
 from functools import wraps
 import math
 import statistics
-from typing import TYPE_CHECKING, Any, NoReturn
+from typing import TYPE_CHECKING, Any
 
 import jinja2
 from jinja2 import pass_environment
 
-from homeassistant.helpers.template.context import template_cv
+from homeassistant.helpers.template.helpers import raise_no_default
 
 from .base import BaseTemplateExtension, TemplateFunction
 
@@ -22,15 +22,6 @@ if TYPE_CHECKING:
 _SENTINEL = object()
 
 
-def raise_no_default(function: str, value: Any) -> NoReturn:
-    """Log warning if no default is specified."""
-    template, action = template_cv.get() or ("", "rendering or compiling")
-    raise ValueError(
-        f"Template error: {function} got invalid input '{value}' when {action} template"
-        f" '{template}' but no default was specified"
-    )
-
-
 class MathExtension(BaseTemplateExtension):
     """Jinja2 extension for mathematical and statistical functions."""
 

homeassistant/helpers/template/helpers.py

@@ -0,0 +1,16 @@
+"""Template helper functions for Home Assistant."""
+
+from __future__ import annotations
+
+from typing import Any, NoReturn
+
+from .context import template_cv
+
+
+def raise_no_default(function: str, value: Any) -> NoReturn:
+    """Raise ValueError when no default is specified for template functions."""
+    template, action = template_cv.get() or ("", "rendering or compiling")
+    raise ValueError(
+        f"Template error: {function} got invalid input '{value}' when {action} template"
+        f" '{template}' but no default was specified"
+    )

tests/helpers/template/test_helpers.py

@@ -0,0 +1,14 @@
+"""Test template helper functions."""
+
+import pytest
+
+from homeassistant.helpers.template.helpers import raise_no_default
+
+
+def test_raise_no_default() -> None:
+    """Test raise_no_default raises ValueError with correct message."""
+    with pytest.raises(
+        ValueError,
+        match="Template error: test got invalid input 'invalid' when rendering or compiling template '' but no default was specified",
+    ):
+        raise_no_default("test", "invalid")