fix: trailing blank page (#78)

* fix: trailing section

* version bump

Author: reindervdw-cmi

pyproject.toml

@@ -1,6 +1,6 @@
 [project]
 name = "cmi-docx"
-version = "0.6.9"
+version = "0.6.10"
 description = "Additional tooling for Python-docx."
 readme = "README.md"
 requires-python = ">=3.12"

src/cmi_docx/declarative/document.py

@@ -143,14 +143,18 @@ async def to_docx(  # noqa: C901
 
         paragraph_index = template.paragraph_index if template is not None else None
         insertion_offset = 0
-        for sec in self.sections:
+        for i, sec in enumerate(self.sections):
             current_index = (
                 (paragraph_index + insertion_offset)
                 if paragraph_index is not None
                 else None
             )
             elements_inserted = _pack_section(
-                docx_doc, sec, self.comment_author, current_index
+                docx_doc,
+                sec,
+                self.comment_author,
+                current_index,
+                is_last=(i == len(self.sections) - 1),
             )
             insertion_offset += elements_inserted
 
@@ -430,6 +434,8 @@ def _pack_section(  # noqa: C901, PLR0912
     sec: section.Section,
     default_comment_author: str | None,
     paragraph_index: int | None = None,
+    *,
+    is_last: bool = False,
 ) -> int:
     """Pack a Section into a python-docx document.
 
@@ -439,6 +445,8 @@ def _pack_section(  # noqa: C901, PLR0912
         default_comment_author: Default author for comments.
         paragraph_index: If provided, insert children starting at this paragraph
             index instead of appending.
+        is_last: If True, skip adding a new section at the end (avoids a
+            trailing blank page after the final section).
 
     Returns:
         The number of block elements inserted (for offset tracking).
@@ -522,7 +530,8 @@ def _pack_section(  # noqa: C901, PLR0912
                 docx_doc, current_section, footer_type, footer, default_comment_author
             )
 
-    docx_doc.add_section()
+    if not is_last:
+        docx_doc.add_section()
 
     return paragraphs_inserted
 

tests/declarative/test_section_margins.py

@@ -30,7 +30,7 @@ async def test_all_margins() -> None:
     )
 
     docx_doc = await doc.to_docx()
-    section = docx_doc.sections[-2]
+    section = docx_doc.sections[-1]
     assert section.top_margin == Inches(2)
     assert section.bottom_margin == Inches(2)
     assert section.left_margin == Inches(2)
@@ -60,7 +60,7 @@ async def test_partial_margins() -> None:
     )
 
     docx_doc = await doc.to_docx()
-    section = docx_doc.sections[-2]
+    section = docx_doc.sections[-1]
     assert section.top_margin == Inches(1.5)
     assert section.left_margin == Inches(1.5)
     assert section.bottom_margin != Inches(1.5)
@@ -84,7 +84,7 @@ async def test_no_margins() -> None:
     )
 
     docx_doc = await doc.to_docx()
-    section = docx_doc.sections[-2]
+    section = docx_doc.sections[-1]
     assert section.top_margin is not None
     assert section.bottom_margin is not None
     assert section.left_margin is not None

tests/declarative/test_section_properties.py

@@ -25,7 +25,7 @@ async def test_landscape_no_page_size() -> None:
     )
 
     docx_doc = await doc.to_docx()
-    section = docx_doc.sections[-2]
+    section = docx_doc.sections[-1]
     assert section.page_width is not None
     assert section.page_height is not None
     assert section.page_width > section.page_height
@@ -52,7 +52,7 @@ async def test_landscape_with_page_size() -> None:
     )
 
     docx_doc = await doc.to_docx()
-    section = docx_doc.sections[-2]
+    section = docx_doc.sections[-1]
     assert section.page_width is not None
     assert section.page_height is not None
     assert section.page_width > section.page_height
@@ -77,7 +77,7 @@ async def test_portrait_no_page_size() -> None:
     )
 
     docx_doc = await doc.to_docx()
-    section = docx_doc.sections[-2]
+    section = docx_doc.sections[-1]
     assert section.page_width is not None
     assert section.page_height is not None
     assert section.page_width < section.page_height
@@ -99,7 +99,7 @@ async def test_no_orientation() -> None:
     )
 
     docx_doc = await doc.to_docx()
-    section = docx_doc.sections[-2]
+    section = docx_doc.sections[-1]
     assert section.page_width is not None
     assert section.page_height is not None
 
@@ -109,13 +109,8 @@ async def test_landscape_multi_section() -> None:
     """Test that landscape properties apply to the correct section index.
 
     With 2 declarative sections (portrait then landscape), the resulting
-    docx_doc.sections list has 3 entries: sections[0] is portrait, sections[1]
-    is landscape, and sections[2] is the trailing empty section added by the
-    final add_section() call.
-
-    This test would have failed with the old off-by-one bug, where landscape
-    properties were applied to sections[2] (the trailing sentinel) instead of
-    sections[1] (the second declarative section).
+    docx_doc.sections list has exactly 2 entries: sections[0] is portrait
+    and sections[1] is landscape.
     """
     doc = declarative.Document(
         sections=[
@@ -137,8 +132,8 @@ async def test_landscape_multi_section() -> None:
     docx_doc = await doc.to_docx()
     sections = list(docx_doc.sections)
 
-    # 2 declarative sections produce 3 total sections (trailing sentinel at [-1]).
-    expected_section_count = 3
+    # 2 declarative sections produce exactly 2 sections.
+    expected_section_count = 2
     assert len(sections) == expected_section_count
 
     portrait_section = sections[0]