sphinxdocs: fix rendering of args in directives with empty doc (#2313)

This fixes a bug where tag-classes/functions that didn't have a doc
string, but did
have arguments/attributes, would render the args/attrs immediately after
the directive
line, which made them get interpreter as direction options (settings
that apply to
the overall directive) instead of doc fields nested within the directive
(separate
block-level elements that get rendered).

To fix, update the code to ensure there's a newline between the
directive line and
subsequent arg/attr lines. Also adds tests for this.

Author: rickeylev

sphinxdocs/private/proto_to_markdown.py

@@ -182,7 +182,7 @@ def _render_module_extension(self, mod_ext: stardoc_output_pb2.ModuleExtensionIn
         for tag in mod_ext.tag_class:
             tag_name = f"{mod_ext.extension_name}.{tag.tag_name}"
             tag_name = f"{tag.tag_name}"
-            self._write(":::::{bzl:tag-class} ", tag_name, "\n\n")
+            self._write(":::::{bzl:tag-class} ")
 
             _sort_attributes_inplace(tag.attribute)
             self._render_signature(
@@ -192,7 +192,12 @@ def _render_module_extension(self, mod_ext: stardoc_output_pb2.ModuleExtensionIn
                 get_default=lambda a: a.default_value,
             )
 
-            self._write(tag.doc_string.strip(), "\n\n")
+            if doc_string := tag.doc_string.strip():
+                self._write(doc_string, "\n\n")
+            # Ensure a newline between the directive and the doc fields,
+            # otherwise they get parsed as directive options instead.
+            if not doc_string and tag.attribute:
+                self.write("\n")
             self._render_attributes(tag.attribute)
             self._write(":::::\n")
         self._write("::::::\n")
@@ -292,10 +297,15 @@ def _render_func(self, func: stardoc_output_pb2.StarlarkFunctionInfo):
 
         parameters = self._render_func_signature(func)
 
-        if doc_string := func.doc_string.strip():
+        doc_string = func.doc_string.strip()
+        if doc_string:
             self._write(doc_string, "\n\n")
 
         if parameters:
+            # Ensure a newline between the directive and the doc fields,
+            # otherwise they get parsed as directive options instead.
+            if not doc_string:
+                self._write("\n")
             for param in parameters:
                 self._write(f":arg {param.name}:\n")
                 if param.default_value:

sphinxdocs/tests/proto_to_markdown/proto_to_markdown_test.py

@@ -209,6 +209,62 @@ def test_render_typedefs(self):
         self.assertIn("\n::::::::::::{bzl:typedef} Carl.ns.Alpha\n", actual)
         self.assertIn("\n:::::::::::::{bzl:typedef} Zeta\n", actual)
 
+    def test_render_func_no_doc_with_args(self):
+        proto_text = """
+file: "@repo//pkg:foo.bzl"
+func_info: {
+  function_name: "func"
+  parameter: {
+    name: "param"
+    doc_string: "param_doc"
+  }
+}
+"""
+        actual = self._render(proto_text)
+        expected = """
+:::::::::::::{bzl:function} func(*param)
+
+:arg param:
+  param_doc
+
+:::::::::::::
+"""
+        self.assertIn(expected, actual)
+
+    def test_render_module_extension(self):
+        proto_text = """
+file: "@repo//pkg:foo.bzl"
+module_extension_info: {
+  extension_name: "bzlmod_ext"
+  tag_class: {
+    tag_name: "bzlmod_ext_tag_a"
+    doc_string: "BZLMOD_EXT_TAG_A_DOC_STRING"
+    attribute: {
+      name: "attr1",
+      doc_string: "attr1doc"
+      type: STRING_LIST
+    }
+  }
+}
+"""
+        actual = self._render(proto_text)
+        expected = """
+:::::{bzl:tag-class} bzlmod_ext_tag_a(attr1)
+
+BZLMOD_EXT_TAG_A_DOC_STRING
+
+:attr attr1:
+  {type}`list[str]`
+  attr1doc
+  :::{bzl:attr-info} Info
+  :::
+
+
+:::::
+::::::
+"""
+        self.assertIn(expected, actual)
+
 
 if __name__ == "__main__":
     absltest.main()