comments: package-loader loads CommentsPart

CommentsPart is loaded as XML-part on document deserialization.

Author: scanny

features/doc-comments.feature

@@ -5,7 +5,6 @@ Feature: Document.comments
   And I need methods allowing access to the comments in the collection
 
 
-  @wip
   Scenario Outline: Access document comments
     Given a document having <a-or-no> comments part
      Then document.comments is a Comments object

src/docx/__init__.py

@@ -25,6 +25,7 @@
 from docx.opc.constants import RELATIONSHIP_TYPE as RT
 from docx.opc.part import PartFactory
 from docx.opc.parts.coreprops import CorePropertiesPart
+from docx.parts.comments import CommentsPart
 from docx.parts.document import DocumentPart
 from docx.parts.hdrftr import FooterPart, HeaderPart
 from docx.parts.image import ImagePart
@@ -41,6 +42,7 @@ def part_class_selector(content_type: str, reltype: str) -> Type[Part] | None:
 
 PartFactory.part_class_selector = part_class_selector
 PartFactory.part_type_for[CT.OPC_CORE_PROPERTIES] = CorePropertiesPart
+PartFactory.part_type_for[CT.WML_COMMENTS] = CommentsPart
 PartFactory.part_type_for[CT.WML_DOCUMENT_MAIN] = DocumentPart
 PartFactory.part_type_for[CT.WML_FOOTER] = FooterPart
 PartFactory.part_type_for[CT.WML_HEADER] = HeaderPart
@@ -51,6 +53,7 @@ def part_class_selector(content_type: str, reltype: str) -> Type[Part] | None:
 del (
     CT,
     CorePropertiesPart,
+    CommentsPart,
     DocumentPart,
     FooterPart,
     HeaderPart,

src/docx/parts/comments.py

@@ -3,7 +3,7 @@
 from __future__ import annotations
 
 import os
-from typing import cast
+from typing import TYPE_CHECKING, cast
 
 from typing_extensions import Self
 
@@ -15,6 +15,10 @@
 from docx.package import Package
 from docx.parts.story import StoryPart
 
+if TYPE_CHECKING:
+    from docx.oxml.comments import CT_Comments
+    from docx.package import Package
+
 
 class CommentsPart(StoryPart):
     """Container part for comments added to the document."""

tests/parts/test_comments.py

@@ -8,18 +8,34 @@
 
 from docx.comments import Comments
 from docx.opc.constants import CONTENT_TYPE as CT
+from docx.opc.constants import RELATIONSHIP_TYPE as RT
 from docx.opc.packuri import PackURI
+from docx.opc.part import PartFactory
 from docx.oxml.comments import CT_Comments
 from docx.package import Package
 from docx.parts.comments import CommentsPart
 
 from ..unitutil.cxml import element
-from ..unitutil.mock import FixtureRequest, Mock, class_mock, instance_mock
+from ..unitutil.mock import FixtureRequest, Mock, class_mock, instance_mock, method_mock
 
 
 class DescribeCommentsPart:
     """Unit test suite for `docx.parts.comments.CommentsPart` objects."""
 
+    def it_is_used_by_the_part_loader_to_construct_a_comments_part(
+        self, package_: Mock, CommentsPart_load_: Mock, comments_part_: Mock
+    ):
+        partname = PackURI("/word/comments.xml")
+        content_type = CT.WML_COMMENTS
+        reltype = RT.COMMENTS
+        blob = b"<w:comments/>"
+        CommentsPart_load_.return_value = comments_part_
+
+        part = PartFactory(partname, content_type, reltype, blob, package_)
+
+        CommentsPart_load_.assert_called_once_with(partname, content_type, blob, package_)
+        assert part is comments_part_
+
     def it_provides_access_to_its_comments_collection(
         self, Comments_: Mock, comments_: Mock, package_: Mock
     ):
@@ -58,6 +74,14 @@ def Comments_(self, request: FixtureRequest) -> Mock:
     def comments_(self, request: FixtureRequest) -> Mock:
         return instance_mock(request, Comments)
 
+    @pytest.fixture
+    def comments_part_(self, request: FixtureRequest) -> Mock:
+        return instance_mock(request, CommentsPart)
+
+    @pytest.fixture
+    def CommentsPart_load_(self, request: FixtureRequest) -> Mock:
+        return method_mock(request, CommentsPart, "load", autospec=False)
+
     @pytest.fixture
     def package_(self, request: FixtureRequest) -> Mock:
         return instance_mock(request, Package)