fix(changelog): ensure changelog_message_builder_hook can access an…

…d modify `change_type` (#1002)

commitizen/changelog.py

@@ -159,14 +159,13 @@ def generate_tree_from_commits(
         message = map_pat.match(commit.message)
         if message:
             parsed_message: dict = message.groupdict()
-            # change_type becomes optional by providing None
-            change_type = parsed_message.pop("change_type", None)
 
-            if change_type_map:
-                change_type = change_type_map.get(change_type, change_type)
             if changelog_message_builder_hook:
                 parsed_message = changelog_message_builder_hook(parsed_message, commit)
             if parsed_message:
+                change_type = parsed_message.pop("change_type", None)
+                if change_type_map:
+                    change_type = change_type_map.get(change_type, change_type)
                 changes[change_type].append(parsed_message)
 
         # Process body from commit message
@@ -177,14 +176,14 @@ def generate_tree_from_commits(
                 continue
             parsed_message_body: dict = message_body.groupdict()
 
-            change_type = parsed_message_body.pop("change_type", None)
-            if change_type_map:
-                change_type = change_type_map.get(change_type, change_type)
             if changelog_message_builder_hook:
                 parsed_message_body = changelog_message_builder_hook(
                     parsed_message_body, commit
                 )
             if parsed_message_body:
+                change_type = parsed_message_body.pop("change_type", None)
+                if change_type_map:
+                    change_type = change_type_map.get(change_type, change_type)
                 changes[change_type].append(parsed_message_body)
 
     yield {"version": current_tag_name, "date": current_tag_date, "changes": changes}

tests/test_changelog.py

@@ -1347,6 +1347,37 @@ def changelog_message_builder_hook(message: dict, commit: git.GitCommit):
             assert RE_HEADER.match(line), f"Line {no} should not be there: {line}"
 
 
+def test_changelog_message_builder_hook_can_access_and_modify_change_type(
+    gitcommits, tags, any_changelog_format: ChangelogFormat
+):
+    def changelog_message_builder_hook(message: dict, commit: git.GitCommit):
+        assert "change_type" in message
+        message["change_type"] = "overridden"
+        return message
+
+    parser = ConventionalCommitsCz.commit_parser
+    changelog_pattern = ConventionalCommitsCz.changelog_pattern
+    loader = ConventionalCommitsCz.template_loader
+    template = any_changelog_format.template
+    tree = changelog.generate_tree_from_commits(
+        gitcommits,
+        tags,
+        parser,
+        changelog_pattern,
+        changelog_message_builder_hook=changelog_message_builder_hook,
+    )
+    result = changelog.render_changelog(tree, loader, template)
+
+    RE_HEADER = re.compile(r"^### (?P<type>.+)$")
+    # There should be only "overridden" change type headers
+    for no, line in enumerate(result.splitlines()):
+        if (line := line.strip()) and (match := RE_HEADER.match(line)):
+            change_type = match.group("type")
+            assert (
+                change_type == "overridden"
+            ), f"Line {no}: type {change_type} should have been overridden"
+
+
 def test_get_smart_tag_range_returns_an_extra_for_a_range(tags):
     start, end = (
         tags[0],