Add pretty printing, key sorting, and better performance to to_json in Jinja

homeassistant/helpers/template.py

@@ -42,6 +42,7 @@
 from jinja2.sandbox import ImmutableSandboxedEnvironment
 from jinja2.utils import Namespace
 from lru import LRU  # pylint: disable=no-name-in-module
+import orjson
 import voluptuous as vol
 
 from homeassistant.const import (
@@ -150,6 +151,10 @@
 )
 ENTITY_COUNT_GROWTH_FACTOR = 1.2
 
+ORJSON_PASSTHROUGH_OPTIONS = (
+    orjson.OPT_PASSTHROUGH_DATACLASS | orjson.OPT_PASSTHROUGH_DATETIME
+)
+
 
 def _template_state_no_collect(hass: HomeAssistant, state: State) -> TemplateState:
     """Return a TemplateState for a state without collecting."""
@@ -2031,9 +2036,31 @@ def from_json(value):
 
 def to_json(value, ensure_ascii=True):
     """Convert an object to a JSON string."""
+    _LOGGER.warning("Template warning: 'to_json' is deprecated, use 'as_json' instead")
     return json.dumps(value, ensure_ascii=ensure_ascii)
 
 
+def _as_json_default(obj):
+    """Disable custom types in json serialization."""
+    raise TypeError(f"Object of type {type(obj).__name__} is not JSON serializable")
+
+
+def as_json(value, pretty_print=False, sort_keys=False):
+    """Convert an object to a JSON string."""
+
+    option = (
+        ORJSON_PASSTHROUGH_OPTIONS
+        | (orjson.OPT_INDENT_2 if pretty_print else 0)
+        | (orjson.OPT_SORT_KEYS if sort_keys else 0)
+    )
+
+    return orjson.dumps(
+        value,
+        option=option,
+        default=_as_json_default,
+    ).decode("utf-8")
+
+
 @pass_context
 def random_every_time(context, values):
     """Choose a random value.
@@ -2259,7 +2286,8 @@ def __init__(self, hass, limited=False, strict=False):
         self.filters["timestamp_custom"] = timestamp_custom
         self.filters["timestamp_local"] = timestamp_local
         self.filters["timestamp_utc"] = timestamp_utc
-        self.filters["to_json"] = to_json
+        self.filters["to_json"] = to_json  # deprecated
+        self.filters["as_json"] = as_json
         self.filters["from_json"] = from_json
         self.filters["is_defined"] = fail_when_undefined
         self.filters["average"] = average

tests/helpers/test_template.py

@@ -10,6 +10,7 @@
 from unittest.mock import patch
 
 from freezegun import freeze_time
+import orjson
 import pytest
 import voluptuous as vol
 
@@ -1048,6 +1049,35 @@ def test_to_json(hass: HomeAssistant) -> None:
     assert actual_result == expected_result
 
 
+def test_as_json(hass: HomeAssistant) -> None:
+    """Test the object to JSON string filter."""
+
+    # Note that we're not testing the actua orjson.dumps methods,
+    # only the filters, so we don't need to be exhaustive with our sample JSON.
+    expected_result = {"Foo": "Bar"}
+    actual_result = template.Template(
+        "{{ {'Foo': 'Bar'} | as_json }}", hass
+    ).async_render()
+    assert actual_result == expected_result
+
+    expected_result = orjson.dumps({"Foo": "Bar"}, option=orjson.OPT_INDENT_2).decode()
+    actual_result = template.Template(
+        "{{ {'Foo': 'Bar'} | as_json(pretty_print=True) }}", hass
+    ).async_render(parse_result=False)
+    assert actual_result == expected_result
+
+    expected_result = orjson.dumps(
+        {"Z": 26, "A": 1, "M": 13}, option=orjson.OPT_SORT_KEYS
+    ).decode()
+    actual_result = template.Template(
+        "{{ {'Z': 26, 'A': 1, 'M': 13} | as_json(sort_keys=True) }}", hass
+    ).async_render(parse_result=False)
+    assert actual_result == expected_result
+
+    with pytest.raises(TemplateError):
+        template.Template("{{ {'Foo': now()} | as_json }}", hass).async_render()
+
+
 def test_to_json_string(hass: HomeAssistant) -> None:
     """Test the object to JSON string filter."""