cli tag: create a tag forget command

CHANGELOG.md

@@ -58,6 +58,8 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 * `jj git fetch` now automatically prints new remote branches and tags by default.
 
+* New `jj tag forget` command.
+
 * `--verbose/-v` is now `--debug` (no short option since it's not intended to be used often)
 
 * `jj move --from/--to` can now be abbreviated to `jj move -f/-t`

cli/src/commands/tag.rs

@@ -12,16 +12,22 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
+use std::io::Write;
+
+use itertools::Itertools;
+use jj_lib::op_store::RefTarget;
 use jj_lib::str_util::StringPattern;
 
-use crate::cli_util::{parse_string_pattern, CommandError, CommandHelper};
+use crate::cli_util::{parse_string_pattern, user_error, CommandError, CommandHelper};
 use crate::ui::Ui;
 
 /// Manage tags.
 #[derive(clap::Subcommand, Clone, Debug)]
 pub enum TagCommand {
     #[command(visible_alias("l"))]
     List(TagListArgs),
+    #[command(visible_alias("f"))]
+    Forget(TagForgetArgs),
 }
 
 /// List tags.
@@ -36,13 +42,26 @@ pub struct TagListArgs {
     pub names: Vec<StringPattern>,
 }
 
+/// Forget tags. They may be recreated on `fetch`.
+#[derive(clap::Args, Clone, Debug)]
+pub struct TagForgetArgs {
+    /// Forget tags whose local name matches
+    ///
+    /// By default, the specified name matches exactly. Use `glob:` prefix to
+    /// select tags by wildcard pattern. For details, see
+    /// https://github.com/martinvonz/jj/blob/main/docs/revsets.md#string-patterns.
+    #[arg(required = true, value_parser = parse_string_pattern)]
+    pub names: Vec<StringPattern>,
+}
+
 pub fn cmd_tag(
     ui: &mut Ui,
     command: &CommandHelper,
     subcommand: &TagCommand,
 ) -> Result<(), CommandError> {
     match subcommand {
         TagCommand::List(sub_args) => cmd_tag_list(ui, command, sub_args),
+        TagCommand::Forget(sub_args) => cmd_tag_forget(ui, command, sub_args),
     }
 }
 
@@ -69,3 +88,43 @@ fn cmd_tag_list(
 
     Ok(())
 }
+
+fn cmd_tag_forget(
+    ui: &mut Ui,
+    command: &CommandHelper,
+    args: &TagForgetArgs,
+) -> Result<(), CommandError> {
+    let mut workspace_command = command.workspace_helper(ui)?;
+    let mut tx = workspace_command.start_transaction();
+    let view = tx.repo().base_repo().view();
+
+    let mut to_forget = vec![];
+    let mut unmatched_patterns = vec![];
+    for pattern in args.names.iter() {
+        let mut matched = false;
+        for tagname in view.tags().keys().filter(|name| pattern.matches(name)) {
+            matched = true;
+            to_forget.push(tagname.clone());
+        }
+        if !matched {
+            unmatched_patterns.push(pattern.to_string())
+        }
+    }
+    if !unmatched_patterns.is_empty() {
+        return Err(user_error(format!(
+            "No matching tags for patterns: {}",
+            unmatched_patterns.into_iter().join(", ")
+        )));
+    }
+    for tagname in to_forget.iter() {
+        // Forgetting a tag is the same as deleting it at the moment, as we never push
+        // tags.
+        tx.mut_repo().set_tag_target(tagname, RefTarget::absent());
+    }
+    tx.finish(ui, format!("forgot {} tags", to_forget.len()))?;
+
+    if to_forget.len() > 1 {
+        writeln!(ui.stderr(), "Forgot {} branches.", to_forget.len())?;
+    };
+    Ok(())
+}

cli/tests/cli-reference@.md.snap

@@ -76,6 +76,7 @@ This document contains the help content for the `jj` command-line program.
 * [`jj status`↴](#jj-status)
 * [`jj tag`↴](#jj-tag)
 * [`jj tag list`↴](#jj-tag-list)
+* [`jj tag forget`↴](#jj-tag-forget)
 * [`jj util`↴](#jj-util)
 * [`jj util completion`↴](#jj-util-completion)
 * [`jj util gc`↴](#jj-util-gc)
@@ -1703,6 +1704,7 @@ Manage tags
 ###### **Subcommands:**
 
 * `list` — List tags
+* `forget` — Forget tags. They may be recreated on `fetch`
 
 
 
@@ -1718,6 +1720,18 @@ List tags
 
 
 
+## `jj tag forget`
+
+Forget tags. They may be recreated on `fetch`
+
+**Usage:** `jj tag forget <NAMES>...`
+
+###### **Arguments:**
+
+* `<NAMES>` — Forget tags whose local name matches
+
+
+
 ## `jj util`
 
 Infrequently used commands such as for generating shell completions

cli/tests/test_tag_command.rs

@@ -12,6 +12,8 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
+use itertools::Itertools;
+
 use crate::common::TestEnvironment;
 
 fn set_up_tagged_git_repo(git_repo: &git2::Repository) {
@@ -77,3 +79,70 @@ fn test_tag_list() {
         test_tag2
          "###);
 }
+
+#[test]
+fn test_tag_forget() {
+    let test_env = TestEnvironment::default();
+    test_env.add_config("git.auto-local-branch = true");
+    let git_repo_path = test_env.env_root().join("source");
+    let git_repo = git2::Repository::init(git_repo_path).unwrap();
+
+    set_up_tagged_git_repo(&git_repo);
+
+    test_env.jj_cmd_ok(test_env.env_root(), &["git", "clone", "source", "tagged"]);
+
+    let local_path = test_env.env_root().join("tagged");
+    insta::assert_snapshot!(
+        test_env.jj_cmd_success(&local_path, &["tag", "list"]),
+        @r###"
+        test_tag
+        test_tag2
+         "###);
+
+    insta::assert_snapshot!(
+        test_env.jj_cmd_success(&local_path, &["tag", "forget", "test_tag2"]),
+        @"");
+    insta::assert_snapshot!(
+        test_env.jj_cmd_success(&local_path, &["tag", "list"]),
+        @r###"
+    test_tag
+    "###);
+
+    // Pushing does not delete the tag on the remote
+    let (_stdout, stderr) = test_env.jj_cmd_ok(&local_path, &["git", "push", "--all"]);
+    insta::assert_snapshot!(stderr,
+        @r###"
+    Nothing changed.
+    "###);
+    insta::assert_debug_snapshot!(
+        git_repo.tag_names(None).unwrap().into_iter().collect_vec(),
+        @r###"
+    [
+        Some(
+            "test_tag",
+        ),
+        Some(
+            "test_tag2",
+        ),
+    ]
+    "###);
+
+    // Fetching recreates the tag
+    let (_stdout, stderr) = test_env.jj_cmd_ok(&local_path, &["git", "fetch"]);
+    insta::assert_snapshot!(stderr,
+        @r###"
+    tag: test_tag2 [new] 
+    "###);
+    insta::assert_snapshot!(
+        test_env.jj_cmd_success(&local_path, &["tag", "list"]),
+        @r###"
+        test_tag
+        test_tag2
+         "###);
+
+    insta::assert_snapshot!(
+        test_env.jj_cmd_failure(&local_path, &["tag", "forget", "test_tag2", "thistagdoesnotexist"]),
+        @r###"
+    Error: No matching tags for patterns: thistagdoesnotexist
+    "###);
+}