feat: Add ability to rename a tag (#213)

Add 'rename tag' subcommand to rename a tag across all repos:

  gitopolis rename tag old_name new_name

If some repos already have the new tag, use --merge to combine:

  gitopolis rename tag old_name new_name --merge

Without --merge, conflicting repos cause an error. Output lists
affected repos for easy verification.

Prompts:
- now this one [Add ability to rename a tag · Issue #213 · timabell/gitopolis](#213)

Fixes #213

bump: minor

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Author: timabell

src/gitopolis.rs

@@ -72,6 +72,17 @@ impl Gitopolis {
 		repos.remove_tag(tag_name, normalize_folders(repo_folders))?;
 		self.save(repos)
 	}
+	pub fn rename_tag(
+		&mut self,
+		old_name: &str,
+		new_name: &str,
+		merge: bool,
+	) -> Result<Vec<String>, GitopolisError> {
+		let mut repos = self.load()?;
+		let affected = repos.rename_tag(old_name, new_name, merge)?;
+		self.save(repos)?;
+		Ok(affected)
+	}
 	pub fn remove_tag_from_all(&mut self, tag_name: &str) -> Result<Vec<String>, GitopolisError> {
 		let mut repos = self.load()?;
 		let affected = repos.remove_tag_from_all(tag_name);

src/main.rs

@@ -110,6 +110,11 @@ enum Commands {
 		#[clap(subcommand)]
 		entity: MoveEntity,
 	},
+	/// Rename a tag or other entity
+	Rename {
+		#[clap(subcommand)]
+		entity: RenameEntity,
+	},
 }
 
 #[derive(Subcommand)]
@@ -123,6 +128,20 @@ enum MoveEntity {
 	},
 }
 
+#[derive(Subcommand)]
+enum RenameEntity {
+	/// Rename a tag across all repos. Use --merge if some repos already have the new tag.
+	Tag {
+		/// Current tag name
+		old_name: String,
+		/// New tag name
+		new_name: String,
+		/// Allow renaming even if some repos already have the new tag
+		#[clap(long)]
+		merge: bool,
+	},
+}
+
 fn main() {
 	env_logger::builder()
 		.format(|buf, record| writeln!(buf, "{}", record.args())) // turn off log decorations https://docs.rs/env_logger/0.9.0/env_logger/#using-a-custom-format
@@ -252,6 +271,28 @@ fn main() {
 				}
 			}
 		},
+		Some(Commands::Rename { entity }) => match entity {
+			RenameEntity::Tag {
+				old_name,
+				new_name,
+				merge,
+			} => match init_gitopolis().rename_tag(old_name, new_name, *merge) {
+				Ok(affected) => {
+					if affected.is_empty() {
+						println!("Tag '{}' not found on any repos", old_name);
+					} else {
+						println!("Renamed tag '{}' to '{}' on:", old_name, new_name);
+						for repo in &affected {
+							println!("{}", repo);
+						}
+					}
+				}
+				Err(error) => {
+					eprintln!("Error: {}", error.message());
+					std::process::exit(1);
+				}
+			},
+		},
 		None => {
 			panic!("no command") // this doesn't happen because help shows instead
 		}

src/repos.rs

@@ -126,6 +126,42 @@ impl Repos {
 	) -> Result<(), GitopolisError> {
 		self.tag(tag_name, repo_folders, true)
 	}
+	pub fn rename_tag(
+		&mut self,
+		old_name: &str,
+		new_name: &str,
+		merge: bool,
+	) -> Result<Vec<String>, GitopolisError> {
+		// Check for conflicts if not merging
+		if !merge {
+			for repo in &self.repos {
+				if repo.tags.iter().any(|t| t == old_name)
+					&& repo.tags.iter().any(|t| t == new_name)
+				{
+					return Err(GitopolisError::StateError {
+						message: format!(
+							"Repo '{}' already has tag '{}'. Use --merge to combine.",
+							repo.path, new_name
+						),
+					});
+				}
+			}
+		}
+
+		let mut affected = Vec::new();
+		for repo in &mut self.repos {
+			if let Some(ix) = repo.tags.iter().position(|t| t == old_name) {
+				repo.tags.remove(ix);
+				if !repo.tags.iter().any(|t| t == new_name) {
+					repo.tags.push(new_name.to_string());
+					repo.tags.sort_by_key(|a| a.to_lowercase());
+				}
+				affected.push(repo.path.clone());
+			}
+		}
+		Ok(affected)
+	}
+
 	pub fn remove_tag_from_all(&mut self, tag_name: &str) -> Vec<String> {
 		let mut affected = Vec::new();
 		for repo in &mut self.repos {

tests/end_to_end_tests.rs

@@ -721,6 +721,82 @@ fn tag_remove_from_all_repos_not_found() {
 		.stdout("Tags nonexistent not found on any repos\n");
 }
 
+#[test]
+fn rename_tag() {
+	let temp = temp_folder();
+	add_a_repo_with_tags(&temp, "repo1", "git://example.org/url1", vec!["old_name"]);
+	add_a_repo_with_tags(
+		&temp,
+		"repo2",
+		"git://example.org/url2",
+		vec!["old_name", "other"],
+	);
+
+	gitopolis_executable()
+		.current_dir(&temp)
+		.args(vec!["rename", "tag", "old_name", "new_name"])
+		.assert()
+		.success()
+		.stdout("Renamed tag 'old_name' to 'new_name' on:\nrepo1\nrepo2\n");
+
+	let actual_toml = read_gitopolis_state_toml(&temp);
+	assert!(actual_toml.contains("\"new_name\""));
+	assert!(!actual_toml.contains("\"old_name\""));
+}
+
+#[test]
+fn rename_tag_merge() {
+	let temp = temp_folder();
+	add_a_repo_with_tags(&temp, "repo1", "git://example.org/url1", vec!["old_name"]);
+	add_a_repo_with_tags(
+		&temp,
+		"repo2",
+		"git://example.org/url2",
+		vec!["new_name", "old_name"],
+	);
+
+	gitopolis_executable()
+		.current_dir(&temp)
+		.args(vec!["rename", "tag", "old_name", "new_name", "--merge"])
+		.assert()
+		.success()
+		.stdout("Renamed tag 'old_name' to 'new_name' on:\nrepo1\nrepo2\n");
+
+	let actual_toml = read_gitopolis_state_toml(&temp);
+	assert!(!actual_toml.contains("\"old_name\""));
+}
+
+#[test]
+fn rename_tag_conflict_without_merge() {
+	let temp = temp_folder();
+	add_a_repo_with_tags(
+		&temp,
+		"repo1",
+		"git://example.org/url1",
+		vec!["old_name", "new_name"],
+	);
+
+	gitopolis_executable()
+		.current_dir(&temp)
+		.args(vec!["rename", "tag", "old_name", "new_name"])
+		.assert()
+		.failure()
+		.stderr(predicates::str::contains("Use --merge to combine"));
+}
+
+#[test]
+fn rename_tag_not_found() {
+	let temp = temp_folder();
+	add_a_repo_with_tags(&temp, "repo1", "git://example.org/url1", vec!["other"]);
+
+	gitopolis_executable()
+		.current_dir(&temp)
+		.args(vec!["rename", "tag", "nonexistent", "new_name"])
+		.assert()
+		.success()
+		.stdout("Tag 'nonexistent' not found on any repos\n");
+}
+
 #[test]
 fn tags() {
 	let temp = temp_folder();

tests/gitopolis_tests.rs

@@ -489,6 +489,146 @@ url = \"git://example.org/repo3\"
 	assert_eq!(vec!["repo1", "repo2"], affected);
 }
 
+#[test]
+fn rename_tag() {
+	let starting_state = "[[repos]]
+path = \"repo1\"
+tags = [\"old_tag\"]
+
+[repos.remotes.origin]
+name = \"origin\"
+url = \"git://example.org/repo1\"
+
+[[repos]]
+path = \"repo2\"
+tags = [\"old_tag\", \"other\"]
+
+[repos.remotes.origin]
+name = \"origin\"
+url = \"git://example.org/repo2\"
+
+[[repos]]
+path = \"repo3\"
+tags = [\"other\"]
+
+[repos.remotes.origin]
+name = \"origin\"
+url = \"git://example.org/repo3\"\
+";
+
+	let expected_toml = "[[repos]]
+path = \"repo1\"
+tags = [\"new_tag\"]
+
+[repos.remotes.origin]
+name = \"origin\"
+url = \"git://example.org/repo1\"
+
+[[repos]]
+path = \"repo2\"
+tags = [\"new_tag\", \"other\"]
+
+[repos.remotes.origin]
+name = \"origin\"
+url = \"git://example.org/repo2\"
+
+[[repos]]
+path = \"repo3\"
+tags = [\"other\"]
+
+[repos.remotes.origin]
+name = \"origin\"
+url = \"git://example.org/repo3\"
+";
+
+	let storage = FakeStorage::new()
+		.with_contents(starting_state.to_string())
+		.with_file_saved_callback(|state| assert_eq!(expected_toml.to_owned(), state))
+		.boxed();
+
+	let git = FakeGit::new().boxed();
+	let mut gitopolis = Gitopolis::new(storage, git);
+
+	let affected = gitopolis
+		.rename_tag("old_tag", "new_tag", false)
+		.expect("Failed to rename tag");
+
+	assert_eq!(vec!["repo1", "repo2"], affected);
+}
+
+#[test]
+fn rename_tag_merge() {
+	let starting_state = "[[repos]]
+path = \"repo1\"
+tags = [\"old_tag\"]
+
+[repos.remotes.origin]
+name = \"origin\"
+url = \"git://example.org/repo1\"
+
+[[repos]]
+path = \"repo2\"
+tags = [\"new_tag\", \"old_tag\"]
+
+[repos.remotes.origin]
+name = \"origin\"
+url = \"git://example.org/repo2\"\
+";
+
+	let expected_toml = "[[repos]]
+path = \"repo1\"
+tags = [\"new_tag\"]
+
+[repos.remotes.origin]
+name = \"origin\"
+url = \"git://example.org/repo1\"
+
+[[repos]]
+path = \"repo2\"
+tags = [\"new_tag\"]
+
+[repos.remotes.origin]
+name = \"origin\"
+url = \"git://example.org/repo2\"
+";
+
+	let storage = FakeStorage::new()
+		.with_contents(starting_state.to_string())
+		.with_file_saved_callback(|state| assert_eq!(expected_toml.to_owned(), state))
+		.boxed();
+
+	let git = FakeGit::new().boxed();
+	let mut gitopolis = Gitopolis::new(storage, git);
+
+	let affected = gitopolis
+		.rename_tag("old_tag", "new_tag", true)
+		.expect("Failed to rename tag with merge");
+
+	assert_eq!(vec!["repo1", "repo2"], affected);
+}
+
+#[test]
+fn rename_tag_conflict_without_merge() {
+	let starting_state = "[[repos]]
+path = \"repo1\"
+tags = [\"new_tag\", \"old_tag\"]
+
+[repos.remotes.origin]
+name = \"origin\"
+url = \"git://example.org/repo1\"\
+";
+
+	let storage = FakeStorage::new()
+		.with_contents(starting_state.to_string())
+		.boxed();
+
+	let git = FakeGit::new().boxed();
+	let mut gitopolis = Gitopolis::new(storage, git);
+
+	let result = gitopolis.rename_tag("old_tag", "new_tag", false);
+	assert!(result.is_err());
+}
+
 struct FakeStorage {
 	exists: bool,
 	contents: String,