test: add tests for changelog incremental behavior during bump

Author: josix

commitizen/commands/bump.py

@@ -310,8 +310,9 @@ def __call__(self) -> None:
         changelog_file_name = None
         dry_run = self.arguments["dry_run"]
         if self.changelog_flag:
-            # "changelog_incremental" defaults to None in settings, so we can't
-            # rely on .get(key, True); default to True for bump only when unset.
+            # DEFAULT_SETTINGS provides changelog_incremental=None, so .get("changelog_incremental", True)
+            # would never fall through to the True default. None means "not configured" vs False meaning
+            # "explicitly disabled". During bump, we default to True (incremental) when not configured.
             incremental_setting = self.config.settings.get("changelog_incremental")
             changelog_args = {
                 "unreleased_version": new_tag_version,

commitizen/defaults.py

@@ -100,6 +100,10 @@ class Settings(TypedDict, total=False):
     ],
     "changelog_file": "CHANGELOG.md",
     "changelog_format": None,  # default guessed from changelog_file
+    # None serves as a sentinel for "not configured by user" (distinct from False = explicitly disabled).
+    # During `cz bump`, when unset (None), defaults to True (incremental changelog).
+    # TODO: consider introducing sentinel value for "not configured by user" instead of overloading None,
+    # to avoid confusion with False.
     "changelog_incremental": None,
     "changelog_start_rev": None,
     "changelog_merge_prerelease": False,

tests/commands/test_bump_command.py

@@ -1502,3 +1502,89 @@ def test_bump_deprecate_files_only(util: UtilFixture):
         pytest.raises(ExpectedExit),
     ):
         util.run_cli("bump", "--yes", "--files-only")
+
+
+@pytest.mark.usefixtures("tmp_commitizen_project")
+def test_bump_changelog_incremental_default_not_set(
+    util: UtilFixture, changelog_path: Path, config_path: Path
+):
+    with config_path.open("a", encoding="utf-8") as fp:
+        fp.write("update_changelog_on_bump = true\n")
+
+    util.create_file_and_commit("feat(user): new user")
+    util.run_cli("bump", "--yes")
+    assert git.tag_exist("0.2.0") is True
+
+    with changelog_path.open(encoding="utf-8") as f:
+        content = f.read()
+    with changelog_path.open("w", encoding="utf-8") as f:
+        f.write(content.replace("- **user**: new user", "- **user**: new user\n\nMANUAL NOTE"))
+    util.create_file_and_commit("docs: add manual note to changelog")
+
+    util.create_file_and_commit("feat(admin): new admin")
+    util.run_cli("bump", "--yes")
+    assert git.tag_exist("0.3.0") is True
+
+    with changelog_path.open(encoding="utf-8") as f:
+        out = f.read()
+    assert "0.3.0" in out
+    assert "0.2.0" in out
+    assert "MANUAL NOTE" in out
+
+
+@pytest.mark.usefixtures("tmp_commitizen_project")
+def test_bump_changelog_incremental_set_true(
+    util: UtilFixture, changelog_path: Path, config_path: Path
+):
+    with config_path.open("a", encoding="utf-8") as fp:
+        fp.write("update_changelog_on_bump = true\n")
+        fp.write("changelog_incremental = true\n")
+
+    util.create_file_and_commit("feat(user): new user")
+    util.run_cli("bump", "--yes")
+    assert git.tag_exist("0.2.0") is True
+
+    with changelog_path.open(encoding="utf-8") as f:
+        content = f.read()
+    with changelog_path.open("w", encoding="utf-8") as f:
+        f.write(content.replace("- **user**: new user", "- **user**: new user\n\nMANUAL NOTE"))
+    util.create_file_and_commit("docs: add manual note to changelog")
+
+    util.create_file_and_commit("feat(admin): new admin")
+    util.run_cli("bump", "--yes")
+    assert git.tag_exist("0.3.0") is True
+
+    with changelog_path.open(encoding="utf-8") as f:
+        out = f.read()
+    assert "0.3.0" in out
+    assert "0.2.0" in out
+    assert "MANUAL NOTE" in out
+
+
+@pytest.mark.usefixtures("tmp_commitizen_project")
+def test_bump_changelog_incremental_set_false(
+    util: UtilFixture, changelog_path: Path, config_path: Path
+):
+    with config_path.open("a", encoding="utf-8") as fp:
+        fp.write("update_changelog_on_bump = true\n")
+        fp.write("changelog_incremental = false\n")
+
+    util.create_file_and_commit("feat(user): new user")
+    util.run_cli("bump", "--yes")
+    assert git.tag_exist("0.2.0") is True
+
+    with changelog_path.open(encoding="utf-8") as f:
+        content = f.read()
+    with changelog_path.open("w", encoding="utf-8") as f:
+        f.write(content.replace("- **user**: new user", "- **user**: new user\n\nMANUAL NOTE"))
+    util.create_file_and_commit("docs: add manual note to changelog")
+
+    util.create_file_and_commit("feat(admin): new admin")
+    util.run_cli("bump", "--yes")
+    assert git.tag_exist("0.3.0") is True
+
+    with changelog_path.open(encoding="utf-8") as f:
+        out = f.read()
+    assert "0.3.0" in out
+    assert "0.2.0" in out
+    assert "MANUAL NOTE" not in out