js nodes, update display_prefix

CHANGES

@@ -15,6 +15,9 @@ Incompatible changes
 * #9672: the signature of
   :py:meth:`domains.py.PyObject.get_signature_prefix` has changed to
   return a list of nodes instead of a plain string.
+* ``domains.js.JSObject.display_prefix`` has been changed into a method
+  ``get_display_prefix`` which now returns a list of nodes
+  instead of a plain string.
 
 Deprecated
 ----------

sphinx/domains/javascript.py

@@ -41,9 +41,6 @@ class JSObject(ObjectDescription[Tuple[str, str]]):
     #: added
     has_arguments = False
 
-    #: what is displayed right before the documentation entry
-    display_prefix: str = None
-
     #: If ``allow_nesting`` is ``True``, the object prefixes will be accumulated
     #: based on directive nesting
     allow_nesting = False
@@ -53,6 +50,10 @@ class JSObject(ObjectDescription[Tuple[str, str]]):
         'noindexentry': directives.flag,
     }
 
+    def get_display_prefix(self) -> List[nodes.Node]:
+        #: what is displayed right before the documentation entry
+        return []
+
     def handle_signature(self, sig: str, signode: desc_signature) -> Tuple[str, str]:
         """Breaks down construct signatures
 
@@ -91,9 +92,9 @@ class JSObject(ObjectDescription[Tuple[str, str]]):
         signode['object'] = prefix
         signode['fullname'] = fullname
 
-        if self.display_prefix:
-            signode += addnodes.desc_annotation(self.display_prefix,
-                                                self.display_prefix)
+        display_prefix = self.get_display_prefix()
+        if display_prefix:
+            signode += addnodes.desc_annotation('', '', *display_prefix)
         if prefix:
             signode += addnodes.desc_addname(prefix + '.', prefix + '.')
         elif mod_name:
@@ -227,9 +228,13 @@ class JSCallable(JSObject):
 
 class JSConstructor(JSCallable):
     """Like a callable but with a different prefix."""
-    display_prefix = 'class '
+
     allow_nesting = True
 
+    def get_display_prefix(self) -> List[nodes.Node]:
+        return [addnodes.desc_sig_keyword('class', 'class'),
+                addnodes.desc_sig_space()]
+
 
 class JSModule(SphinxDirective):
     """

tests/test_domain_js.py

@@ -15,7 +15,8 @@ from docutils import nodes
 
 from sphinx import addnodes
 from sphinx.addnodes import (desc, desc_annotation, desc_content, desc_name, desc_parameter,
-                             desc_parameterlist, desc_signature)
+                             desc_parameterlist, desc_sig_keyword, desc_sig_space,
+                             desc_signature)
 from sphinx.domains.javascript import JavaScriptDomain
 from sphinx.testing import restructuredtext
 from sphinx.testing.util import assert_node
@@ -198,7 +199,8 @@ def test_js_class(app):
     text = ".. js:class:: Application"
     doctree = restructuredtext.parse(app, text)
     assert_node(doctree, (addnodes.index,
-                          [desc, ([desc_signature, ([desc_annotation, "class "],
+                          [desc, ([desc_signature, ([desc_annotation, ([desc_sig_keyword, 'class'],
+                                                                       desc_sig_space)],
                                                     [desc_name, "Application"],
                                                     [desc_parameterlist, ()])],
                                   [desc_content, ()])]))