Show the full release notes of a version X.Y.0 from a changelog tha…

CHANGELOG.md

@@ -6,7 +6,9 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/)
 
 ## [Unreleased]
 
-No changes yet.
+### Fixed
+
+- Show the full release notes of a version `X.Y.0` from a changelog that heads the release `X.Y` and names `X.Y.0` in its prose, instead of only its introduction. Closes [#407](https://github.com/ICTU/update-time/issues/407).
 
 ## 0.0.43 - 2026-10-11
 

src/update_time/domain/changelog.py

@@ -105,11 +105,10 @@ def _fenced_indexes(lines: list[str]) -> frozenset[int]:
 
 
 def _find_version_index(lines: list[str], version: str) -> int | None:
-    """Return the index of the line that introduces the version's changes, or None when absent.
+    """Return the index of the heading naming the version, or else of the first line naming it, or None when absent.
 
     A heading naming the version wins over any other line that names it, so that a prose mention inside another
-    version's section (for example "shipped in 0.10.0") doesn't anchor parsing in the wrong place. Where no heading
-    names the version, the first line that names it anchors parsing.
+    version's section (for example "shipped in 0.10.0") doesn't anchor parsing in the wrong place.
     """
     fallback = None
     fenced = _fenced_indexes(lines)
@@ -179,13 +178,28 @@ def _next_version_index(lines: list[str], start: int, version: str) -> int | Non
     return None
 
 
+def _find_anchor(lines: list[str], version: str) -> tuple[str, int | None]:
+    """Return the version as the changelog names it, and the index of the line introducing its changes, if any.
+
+    A changelog can head the changes of a `.0` version one component shorter, `1.11` for `1.11.0`. So a heading
+    naming the shorter version wins over prose naming the version itself. Where no line names the version itself,
+    any line naming the shorter version anchors parsing.
+    """
+    start = _find_version_index(lines, version)
+    if start is not None and _heading_level(lines, start):
+        return version, start
+    if version.endswith(".0") and version.count(".") > 1:
+        short_version = version.removesuffix(".0")
+        short_start = _find_version_index(lines, short_version)
+        if short_start is not None and (start is None or _heading_level(lines, short_start)):
+            return short_version, short_start
+    return version, start
+
+
 def get_version_changes_from_changelog(text: str, version: str) -> str:
     """Return the changes for the version from the changelog, or nothing when the changelog does not name it."""
     all_lines = text.splitlines()
-    start = _find_version_index(all_lines, version)
-    if start is None and version.endswith(".0") and version.count(".") > 1:
-        version = version.removesuffix(".0")
-        start = _find_version_index(all_lines, version)
+    version, start = _find_anchor(all_lines, version)
     if start is None:
         return ""
     end = _next_version_index(all_lines, start, version)

tests/update_time/domain/test_changelog.py

@@ -158,19 +158,16 @@ def test_longer_version_does_not_anchor_parsing(self):
                 self.assertEqual(get_version_changes_from_changelog(text, version), v1_change)
 
     _NO_SHORTER_HEADING = Mutation(
-        changelog.get_version_changes_from_changelog,
-        '    if start is None and version.endswith(".0") and version.count(".") > 1:\n'
-        '        version = version.removesuffix(".0")\n'
-        "        start = _find_version_index(all_lines, version)",
-        "",
+        changelog._find_anchor,
+        'version.endswith(".0") and version.count(".") > 1:',
+        "False:",
         "a changelog heading a release one component shorter than the version reports no changes for it",
     )
 
     _SHORTEN_ANY_VERSION = Mutation(
-        changelog.get_version_changes_from_changelog,
-        'if start is None and version.endswith(".0") and version.count(".") > 1:\n'
-        '        version = version.removesuffix(".0")',
-        'if start is None and version.count(".") > 1:\n        version = version.rsplit(".", 1)[0]',
+        changelog._find_anchor,
+        'version.endswith(".0") and version.count(".") > 1:\n        short_version = version.removesuffix(".0")',
+        'version.count(".") > 1:\n        short_version = version.rsplit(".", 1)[0]',
         "a version that is no `.0` release reports the changes of the release one component shorter",
     )
 
@@ -183,9 +180,9 @@ def test_only_a_dot_zero_version_is_found_under_a_shorter_heading(self):
         self.assertEqual(get_version_changes_from_changelog(text, "1.11.2"), "")
 
     _SHORTER_VERSION_NOT_REBOUND = Mutation(
-        changelog.get_version_changes_from_changelog,
-        'version = version.removesuffix(".0")\n        start = _find_version_index(all_lines, version)',
-        'start = _find_version_index(all_lines, version.removesuffix(".0"))',
+        changelog._find_anchor,
+        "return short_version, short_start",
+        "return version, short_start",
         "a changelog without heading markup naming a shorter version raises instead of reporting its changes",
         raises="ValueError: substring not found",
     )
@@ -198,9 +195,9 @@ def test_dot_zero_version_is_found_under_a_shorter_version_named_in_prose(self):
         self.assertEqual(get_version_changes_from_changelog(text, "1.11.0"), v1_change)
 
     _SHORTER_HEADING_TRIED_FIRST = Mutation(
-        changelog.get_version_changes_from_changelog,
-        "if start is None and",
-        'if _find_version_index(all_lines, version.removesuffix(".0")) is not None and',
+        changelog._find_anchor,
+        "start is not None and _heading_level(lines, start):",
+        "False:",
         "a changelog heading both a version and the release one component shorter reports the shorter one's changes",
     )
 
@@ -211,10 +208,41 @@ def test_heading_naming_the_version_wins_over_a_shorter_heading(self):
         text = f"# Changelog\n\n## 1.11\n\nThe 1.11 series.\n\n{v1_change}\n\n## 1.10\n\n- Fixed ...\n"
         self.assertEqual(get_version_changes_from_changelog(text, "1.11.0"), v1_change)
 
+    _PROSE_WINS_OVER_A_SHORTER_HEADING = Mutation(
+        changelog._find_anchor,
+        " and _heading_level(lines, start):",
+        ":",
+        "a changelog heading a release one component shorter than the version, and naming the version in its prose, "
+        "reports the prose line alone",
+    )
+
+    @kills(_PROSE_WINS_OVER_A_SHORTER_HEADING)
+    def test_shorter_heading_anchors_parsing_rather_than_prose_naming_the_dot_zero_version(self):
+        """Test that a heading naming one component fewer anchors parsing rather than prose naming the version."""
+        v1_change = "## Example 1.11\n\nWe released example 1.11.0.\n\n### New feature\n\n- Added ..."
+        text = f"# Changelog\n\n{v1_change}\n\n## Example 1.10\n\n- Fixed ...\n"
+        self.assertEqual(get_version_changes_from_changelog(text, "1.11.0"), v1_change)
+
+    _SHORTER_PROSE_WINS = Mutation(
+        changelog._find_anchor,
+        " and (start is None or _heading_level(lines, short_start)):",
+        ":",
+        "a changelog without heading markup reports a `.0` version from wherever the version one component shorter "
+        "is first named",
+    )
+
+    @kills(_SHORTER_PROSE_WINS)
+    def test_dot_zero_version_line_anchors_parsing_rather_than_prose_naming_a_shorter_version(self):
+        """Test that without headings, a `.0` version's line anchors parsing, not a line naming a component fewer."""
+        v1_change = "Version 1.11.0 released 2026-04-22\n\n- Fixed ...\n- Changed ..."
+        v2_change = "Version 1.12.0 released 2026-05-01\n\n- Dropped support for 1.11."
+        text = f"Changes\n\n{v2_change}\n\n{v1_change}\n\nVersion 1.10.0 released 2026-03-08\n\n- Fixed ...\n"
+        self.assertEqual(get_version_changes_from_changelog(text, "1.11.0"), v1_change)
+
     _SHORTEN_TO_A_BARE_COMPONENT = Mutation(
-        changelog.get_version_changes_from_changelog,
-        'if start is None and version.endswith(".0") and version.count(".") > 1:',
-        'if start is None and version.endswith(".0"):',
+        changelog._find_anchor,
+        'version.endswith(".0") and version.count(".") > 1:',
+        'version.endswith(".0"):',
         "a changelog naming a two-component version nowhere reports the entry a stray digit sits in",
     )