Fixes issue of duplicate tags

- Now it checks if the tag exists and reports a warning

Author: coordt

README.md

@@ -46,7 +46,7 @@ commits and tags:
 - https://github.com/c4urself/bump2version/issues/246 Release inconsistency
 - https://github.com/c4urself/bump2version/issues/233 How are relative configured file paths resolved?
 - https://github.com/c4urself/bump2version/issues/225 Properly resolve configuration file through parent directories when in a git or mercurial repo
-- https://github.com/c4urself/bump2version/issues/224 Verify tag doesn't exist
+- Fixed: https://github.com/c4urself/bump2version/issues/224 Verify tag doesn't exist
 
 **Documentation opportunities**
 

bumpversion/scm.py

@@ -32,6 +32,7 @@ class SourceCodeManager:
 
     _TEST_USABLE_COMMAND: List[str] = []
     _COMMIT_COMMAND: List[str] = []
+    _ALL_TAGS_COMMAND: List[str] = []
 
     @classmethod
     def commit(cls, message: str, current_version: str, new_version: str, extra_args: Optional[list] = None) -> None:
@@ -84,6 +85,15 @@ def tag(cls, name: str, sign: bool = False, message: Optional[str] = None) -> No
         """Create a tag of the new_version in VCS."""
         raise NotImplementedError
 
+    @classmethod
+    def get_all_tags(cls) -> List[str]:
+        """Return all tags in VCS."""
+        try:
+            result = subprocess.run(cls._ALL_TAGS_COMMAND, text=True, check=True, capture_output=True)
+            return result.stdout.splitlines()
+        except (FileNotFoundError, PermissionError, NotADirectoryError, subprocess.CalledProcessError):
+            return []
+
     @classmethod
     def commit_to_scm(
         cls,
@@ -135,7 +145,13 @@ def tag_in_scm(cls, config: "Config", context: MutableMapping, dry_run: bool = F
         sign_tags = config.sign_tags
         tag_name = config.tag_name.format(**context)
         tag_message = config.tag_message.format(**context)
+        existing_tags = cls.get_all_tags()
         do_tag = config.tag and not dry_run
+
+        if tag_name in existing_tags and config.tag:
+            logger.warning("Tag '%s' already exists. Will not tag.", tag_name)
+            return
+
         logger.info(
             "%s '%s' %s in %s and %s",
             "Tagging" if do_tag else "Would tag",
@@ -153,6 +169,7 @@ class Git(SourceCodeManager):
 
     _TEST_USABLE_COMMAND = ["git", "rev-parse", "--git-dir"]
     _COMMIT_COMMAND = ["git", "commit", "-F"]
+    _ALL_TAGS_COMMAND = ["git", "tag", "--list"]
 
     @classmethod
     def assert_nondirty(cls) -> None:
@@ -241,6 +258,7 @@ class Mercurial(SourceCodeManager):
 
     _TEST_USABLE_COMMAND = ["hg", "root"]
     _COMMIT_COMMAND = ["hg", "commit", "--logfile"]
+    _ALL_TAGS_COMMAND = ["hg", "log", '--rev="tag()"', '--template="{tags}\n"']
 
     @classmethod
     def latest_tag_info(cls, tag_pattern: str) -> SCMInfo:

tests/test_scm.py

@@ -3,10 +3,11 @@
 from pathlib import Path
 
 import pytest
-from pytest import param
+from pytest import param, LogCaptureFixture
 
 from bumpversion import scm
 from bumpversion.exceptions import DirtyWorkingDirectoryError
+from bumpversion.logging import setup_logging
 from tests.conftest import get_config_data, inside_dir
 
 
@@ -42,7 +43,7 @@ def test_git_latest_tag_info(git_repo: Path) -> None:
     """Should return information about the latest tag."""
     readme = git_repo.joinpath("readme.md")
     readme.touch()
-    # with pytest.raises(DirtyWorkingDirectoryError):
+
     with inside_dir(git_repo):
         assert scm.Git.latest_tag_info("v*") == scm.SCMInfo(tool=scm.Git)
 
@@ -65,6 +66,33 @@ def test_git_latest_tag_info(git_repo: Path) -> None:
         assert tag_info.dirty is True
 
 
+def test_git_detects_existing_tag(git_repo: Path, caplog: LogCaptureFixture) -> None:
+    """Attempting to tag when a tag exists will do nothing."""
+    # Arrange
+    git_repo.joinpath("readme.md").touch()
+    git_repo.joinpath("something.md").touch()
+    overrides = {"current_version": "0.1.0", "commit": True, "tag": True}
+    context = {
+        "current_version": "0.1.0",
+        "new_version": "0.2.0",
+    }
+    setup_logging(2)
+    with inside_dir(git_repo):
+        conf, version_config, current_version = get_config_data(overrides)
+        subprocess.run(["git", "add", "readme.md"])
+        subprocess.run(["git", "commit", "-m", "first"])
+        subprocess.run(["git", "tag", "v0.1.0"])
+        subprocess.run(["git", "add", "something.md"])
+        subprocess.run(["git", "commit", "-m", "second"])
+        subprocess.run(["git", "tag", "v0.2.0"])
+
+        # Act
+        scm.Git.tag_in_scm(config=conf, context=context)
+
+    # Assert
+    assert "Will not tag" in caplog.text
+
+
 def test_hg_is_not_usable(tmp_path: Path) -> None:
     """Should return false if it is not a mercurial repo."""
     with inside_dir(tmp_path):