Adds turbo_refreshes_with template tag

For support for morphing coming in Turbo 8, hotwired/turbo#1019

Duplicates the Rails turbo_refreshes_with template helper.

src/turbo_helper/templatetags/turbo_helper.py

@@ -1,9 +1,11 @@
 from typing import Any, Optional
 
 from django import template
+from django.core.exceptions import ValidationError
 from django.db.models.base import Model
 from django.template import Node, TemplateSyntaxError, engines
 from django.template.base import token_kwargs
+from django.utils.html import format_html
 from django.utils.safestring import mark_safe
 
 register = template.Library()
@@ -228,3 +230,19 @@ def turbo_stream_from_tag(parser, token):
     stream_name_array = [parser.compile_filter(bit) for bit in remaining_bits]
 
     return TurboStreamFromTagNode(stream_name_array)
+
+
+@register.simple_tag
+def turbo_refreshes_with(method='replace', scroll='reset') -> str:
+    valid_methods = ['replace', 'morph']
+    valid_scrolls = ['reset', 'preserve']
+
+    if method not in valid_methods:
+        raise ValidationError(f"Invalid refresh option '{method}'")
+    if scroll not in valid_scrolls:
+        raise ValidationError(f"Invalid scroll option '{scroll}'")
+
+    meta_tags = f'<meta name="turbo-refresh-method" content="{method}">'
+    meta_tags += f'<meta name="turbo-refresh-scroll" content="{scroll}">'
+
+    return format_html(meta_tags)

tests/test_tags.py

@@ -1,4 +1,5 @@
 import pytest
+from django.core.exceptions import ValidationError
 from django.template import Context, Template
 
 from tests.testapp.models import TodoItem
@@ -131,3 +132,37 @@ def test_dom_id_variable(self):
             output
             == '<turbo-cable-stream-source channel="TurboStreamCableChannel" signed-stream-name="test_todo_3:7ZS0MxQWhRTCAnG3olGO9AJKfvos3iaHGoBMBt8ZbSM"></turbo-cable-stream-source>'
         )
+
+
+class TestRefreshesWith:
+    def test_turbo_refreshes_with_tag(self):
+        template = """
+        {% load turbo_helper %}
+
+        {% turbo_refreshes_with method='replace' scroll='reset' %}
+        """
+
+        output = render(template, {}).strip()
+
+        expected_method_tag = '<meta name="turbo-refresh-method" content="replace">'
+        expected_scroll_tag = '<meta name="turbo-refresh-scroll" content="reset">'
+
+        assert expected_method_tag in output
+        assert expected_scroll_tag in output
+
+    def test_invalid_options(self):
+        with pytest.raises(ValidationError):
+            template = """
+            {% load turbo_helper %}
+
+            {% turbo_refreshes_with method='invalid' scroll='reset' %}
+            """
+            output = render(template, {}).strip()
+
+        with pytest.raises(ValidationError):
+            template = """
+            {% load turbo_helper %}
+
+            {% turbo_refreshes_with method='replace' scroll='invalid' %}
+            """
+            output = render(template, {}).strip()