Added a :js:func: role to refer to functions described with the js:function:: directive.

doc/domains.rst

@@ -556,3 +556,7 @@ The JavaScript domain (name **js**) provides the following directives:
    Describe a JavaScript function. If you want to document optional
    arguments use square brackets as :ref:`documented <signatures>` for Python
    signatures.
+
+These roles are provided to refer to the described objects:
+
+.. role:: js:func

sphinx/domains/javascript.py

@@ -15,6 +15,7 @@ from sphinx.domains import Domain, ObjType
 from sphinx.locale import l_, _
 from sphinx.directives import ObjectDescription
 from sphinx.domains.python import py_paramlist_re as js_paramlist_re
+from sphinx.roles import XRefRole
 
 js_sig_re = re.compile(r'(\w+)\s*\((.*)\)')
 
@@ -63,3 +64,6 @@ class JavaScriptDomain(Domain):
     directives = {
         "function": JSFunction,
     }
+    roles = {
+        "func": XRefRole(fix_parens=True),
+    }

tests/root/objects.txt

@@ -90,6 +90,9 @@ With target: :c:func:`Sphinx_DoSomething()` (parentheses are handled),
 
 Without target: :c:func:`CFunction`. :c:func:`!malloc`.
 
+:js:func:`foo()`
+:js:func:`foo`
+
 
 Others
 ======