Fix studio xblock failing renders (due to asset hashing loop)

cms/conftest.py

@@ -47,3 +47,15 @@ def _django_clear_site_cache():
     with what has been working for us so far.
     """
     pass
+
+
+@pytest.fixture(autouse=True)
+def no_webpack_loader(monkeypatch):
+    monkeypatch.setattr(
+        "webpack_loader.templatetags.webpack_loader.render_bundle",
+        lambda entry, extension=None, config='DEFAULT', attrs='': ''
+    )
+    monkeypatch.setattr(
+        "webpack_loader.utils.get_as_tags",
+        lambda entry, extension=None, config='DEFAULT', attrs='': []
+    )

cms/djangoapps/contentstore/views/preview.py

@@ -39,7 +39,8 @@ from xmodule.modulestore.django import ModuleI18nService, modulestore
 from xmodule.partitions.partitions_service import PartitionService
 from xmodule.services import SettingsService
 from xmodule.studio_editable import has_author_view
-from xmodule.x_module import AUTHOR_VIEW, PREVIEW_VIEWS, STUDENT_VIEW, ModuleSystem
+from xmodule.x_module import AUTHOR_VIEW, PREVIEW_VIEWS, STUDENT_VIEW, ModuleSystem, XModule, XModuleDescriptor
+import webpack_loader.utils
 
 from .helpers import render_from_lms
 from .session_kv_store import SessionKeyValueStore
@@ -298,6 +299,15 @@ def _studio_wrap_xblock(xblock, view, frag, context, display_name_only=False):
             'language': getattr(course, 'language', None)
         }
 
+        if isinstance(xblock, (XModule, XModuleDescriptor)):
+            # Add the webpackified asset tags
+            class_name = getattr(xblock.__class__, 'unmixed_class', xblock.__class__).__name__
+            for tag in webpack_loader.utils.get_as_tags(class_name):
+                frag.add_resource(tag, mimetype='text/html', placement='head')
+
+        for tag in webpack_loader.utils.get_as_tags("js/factories/xblock_validation"):
+            frag.add_resource(tag, mimetype='text/html', placement='head')
+
         html = render_to_string('studio_xblock_wrapper.html', template_context)
         frag = wrap_fragment(frag, html)
     return frag

cms/templates/studio_xblock_wrapper.html

@@ -7,7 +7,6 @@ from lms.lib.utils import is_unit
 from openedx.core.djangolib.js_utils import (
     dump_js_escaped_json, js_escaped_string
 )
-from xmodule.x_module import XModule, XModuleDescriptor
 %>
 <%
 xblock_url = xblock_studio_url(xblock)
@@ -27,7 +26,7 @@ block_is_unit = is_unit(xblock)
 </script>
 </%block>
 
-<%static:webpack entry="js/factories/xblock_validation">
+<script type="text/javascript">
     XBlockValidationFactory(
         ${messages | n, dump_js_escaped_json},
         ${bool(xblock_url) | n, dump_js_escaped_json},  // xblock_url will be None or a string
@@ -35,11 +34,7 @@ block_is_unit = is_unit(xblock)
         ${bool(block_is_unit) | n, dump_js_escaped_json},  // block_is_unit will be None or a boolean
         $('div.xblock-validation-messages[data-locator="${xblock.location | n, js_escaped_string}"]')
     );
-</%static:webpack>
-
-% if isinstance(xblock, (XModule, XModuleDescriptor)):
-    <%static:webpack entry="${getattr(xblock.__class__, 'unmixed_class', xblock.__class__).__name__}"/>
-% endif
+</script>
 
 % if not is_root:
     % if is_reorderable: