Add template Base64 decode encoding parameter (#116603)

Co-authored-by: Robert Resch <robert@resch.dev>

homeassistant/helpers/template.py

@@ -2397,14 +2397,18 @@ def struct_unpack(value: bytes, format_string: str, offset: int = 0) -> Any | No
         return None
 
 
-def base64_encode(value):
+def base64_encode(value: str) -> str:
     """Perform base64 encode."""
     return base64.b64encode(value.encode("utf-8")).decode("utf-8")
 
 
-def base64_decode(value):
-    """Perform base64 denode."""
-    return base64.b64decode(value).decode("utf-8")
+def base64_decode(value: str, encoding: str | None = "utf-8") -> str | bytes:
+    """Perform base64 decode."""
+    decoded = base64.b64decode(value)
+    if encoding:
+        return decoded.decode(encoding)
+
+    return decoded
 
 
 def ordinal(value):

tests/helpers/test_template.py

@@ -1643,6 +1643,18 @@ def test_base64_decode(hass: HomeAssistant) -> None:
         ).async_render()
         == "homeassistant"
     )
+    assert (
+        template.Template(
+            '{{ "aG9tZWFzc2lzdGFudA==" | base64_decode(None) }}', hass
+        ).async_render()
+        == b"homeassistant"
+    )
+    assert (
+        template.Template(
+            '{{ "aG9tZWFzc2lzdGFudA==" | base64_decode("ascii") }}', hass
+        ).async_render()
+        == "homeassistant"
+    )
 
 
 def test_slugify(hass: HomeAssistant) -> None: