feat: add --allow-no-commit to changelog command (#1868)

* fix: bump command called changelog command with allow_no_commit=True, but changelog command raised NoCommitsFoundError

* fix: clarify allow-no-commit changelog behavior and docs

Align internal typing/forwarding for allow_no_commit, simplify the regression test setup, and document how changelog entries are generated during no-commit bumps.

Made-with: Cursor

* chore: clarify internal changelog allow_no_commit argument

Document that allow_no_commit in ChangelogArgs is internal-only for bump-triggered changelog generation.

Made-with: Cursor

* chore: Apply suggestion from @Copilot

Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>

---------

Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>

Author: bearomorphism

commitizen/commands/bump.py

@@ -330,7 +330,11 @@ def __call__(self) -> None:
 
             changelog_cmd = Changelog(
                 self.config,
-                {**changelog_args, "file_name": self.file_name},  # type: ignore[typeddict-item]
+                {
+                    **changelog_args,  # type: ignore[typeddict-item]
+                    "file_name": self.file_name,
+                    "allow_no_commit": bool(self.arguments["allow_no_commit"]),
+                },
             )
             changelog_cmd()
             changelog_file_name = changelog_cmd.file_name

commitizen/commands/changelog.py

@@ -43,6 +43,7 @@ class ChangelogArgs(TypedDict, total=False):
     extras: dict[str, Any]
     export_template: str
     during_version_bump: bool | None
+    allow_no_commit: bool | None  # Internal-only when invoked by bump.
 
 
 class Changelog:
@@ -124,6 +125,8 @@ def __init__(self, config: BaseConfig, arguments: ChangelogArgs) -> None:
         self.export_template_to = arguments.get("export_template")
 
         self.during_version_bump: bool = arguments.get("during_version_bump") or False
+        # Internal flag used when changelog is invoked from `cz bump --allow-no-commit`.
+        self.allow_no_commit: bool = bool(arguments.get("allow_no_commit"))
 
     def _find_incremental_rev(self, latest_version: str, tags: Iterable[GitTag]) -> str:
         """Try to find the 'start_rev'.
@@ -255,8 +258,10 @@ def __call__(self) -> None:
                     changelog_meta.unreleased_end = latest_full_release_info.index + 1
 
         commits = git.get_commits(start=start_rev, end=end_rev, args="--topo-order")
-        if not commits and (
-            self.current_version is None or not self.current_version.is_prerelease
+        if (
+            not self.allow_no_commit
+            and not commits
+            and (self.current_version is None or not self.current_version.is_prerelease)
         ):
             raise NoCommitsFoundError("No commits found")
 

docs/commands/bump.md

@@ -385,6 +385,11 @@ cz bump --allow-no-commit 2.0.0
     cz bump --allow-no-commit 2.0.0
     ```
 
+!!! note "Behavior with changelog updates"
+    When `update_changelog_on_bump = true` (or `--changelog` is used), `cz bump --allow-no-commit` also generates a changelog entry even if there are no commits in the selected range.
+
+    This makes the new release visible in the changelog while still showing that no commit-based changes were included.
+
 ### `--tag-format`
 
 `tag_format` and [version_scheme][version_scheme] are combined to make Git tag names from versions.

docs/commands/changelog.md

@@ -2,6 +2,8 @@
 
 Generates a changelog following the committing rules established.
 
+When changelog generation is triggered by `cz bump --allow-no-commit` (with `--changelog` or `update_changelog_on_bump = true`), Commitizen still creates a release entry even when no commits are found in the selected revision range.
+
 !!! tip
     To create the changelog automatically on bump, add the setting [update_changelog_on_bump](../config/bump.md#update_changelog_on_bump)
 

tests/commands/test_bump_command.py

@@ -1537,3 +1537,18 @@ def test_changelog_merge_preserves_header(
     out = changelog_path.read_text()
 
     file_regression.check(out, extension=".md")
+
+
+@pytest.mark.freeze_time("2025-01-01")
+def test_bump_allow_no_commit_issue(
+    tmp_commitizen_project_initial,
+    util: UtilFixture,
+) -> None:
+    """Issue #1866: bump command called changelog command with allow_no_commit=True, but changelog command raised NoCommitsFoundError"""
+    tmp_commitizen_project_initial(
+        version="1.0.0", config_extra="update_changelog_on_bump = true\n"
+    )
+    util.run_cli("bump", "--yes", "--allow-no-commit", "--prerelease", "beta")
+    util.run_cli(
+        "bump", "--allow-no-commit", "--prerelease", "rc"
+    )  # Should not fail when changelog generation runs with no new commits