error if new version == current version

tbump/cli.py

@@ -208,6 +208,14 @@ def run_bump(
     bump(bump_options, _construct_operations(arguments))
 
 
+class NotANewVersion(Error):
+    def __init__(self):
+        super().__init__()
+
+    def print_error(self) -> None:
+        ui.error("New version is the same as the previous one")
+
+
 def bump(options: BumpOptions, operations: List[str]) -> None:
     working_path = options.working_path
     new_version = options.new_version
@@ -220,6 +228,9 @@ def bump(options: BumpOptions, operations: List[str]) -> None:
     )
     config = config_file.get_config()
 
+    if config.current_version == new_version:
+        raise NotANewVersion()
+
     # fmt: off
     ui.info_1(
         "Bumping from", ui.bold, config.current_version,

tbump/test/test_cli.py

@@ -5,6 +5,7 @@
 import tomlkit
 
 from tbump.cli import run as run_tbump
+from tbump.cli import NotANewVersion
 from tbump.config import ConfigNotFound, InvalidConfig
 from tbump.error import Error
 from tbump.file_bumper import (
@@ -317,7 +318,7 @@ def test_abort_if_file_does_not_contain_current_version(test_repo: Path) -> None
 def test_no_tracked_branch_but_ref_exists(test_repo: Path) -> None:
     run_git(test_repo, "checkout", "-b", "devel")
 
-    with pytest.raises(RefAlreadyExists):
+    with pytest.raises(NotANewVersion):
         run_tbump(["-C", str(test_repo), "1.2.41-alpha-1"])