cli: support multiple --revision arguments to workspace add

CHANGELOG.md

@@ -11,6 +11,10 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ### New features
 
+* `jj workspace add` can now take _multiple_ `--revision` arguments, which will
+  create a new workspace with its working-copy commit on top of all the parents,
+  as if you had run `jj new r1 r2 r3 ...`.
+
 ### Fixed bugs
 
 

cli/src/cli_util.rs

@@ -1907,6 +1907,23 @@ fn resolve_single_op(
     Ok(operation)
 }
 
+/// Resolves revsets into revisions for use; useful for rebases or operations
+/// that take multiple parents.
+pub fn resolve_all_revs(
+    workspace_command: &WorkspaceCommandHelper,
+    ui: &mut Ui,
+    revisions: &[RevisionArg],
+) -> Result<IndexSet<Commit>, CommandError> {
+    let commits =
+        resolve_multiple_nonempty_revsets_default_single(workspace_command, ui, revisions)?;
+    let root_commit_id = workspace_command.repo().store().root_commit_id();
+    if commits.len() >= 2 && commits.iter().any(|c| c.id() == root_commit_id) {
+        Err(user_error("Cannot merge with root revision"))
+    } else {
+        Ok(commits)
+    }
+}
+
 fn find_all_operations(
     op_store: &Arc<dyn OpStore>,
     op_heads_store: &Arc<dyn OpHeadsStore>,

cli/src/commands/new.rs

@@ -25,7 +25,6 @@ use tracing::instrument;
 use crate::cli_util::{
     self, short_commit_hash, user_error, CommandError, CommandHelper, RevisionArg,
 };
-use crate::commands::rebase::resolve_destination_revs;
 use crate::ui::Ui;
 
 /// Create a new, empty change and edit it in the working copy
@@ -76,7 +75,7 @@ Please use `jj new 'all:x|y'` instead of `jj new --allow-large-revsets x y`.",
         !args.revisions.is_empty(),
         "expected a non-empty list from clap"
     );
-    let target_commits = resolve_destination_revs(&workspace_command, ui, &args.revisions)?
+    let target_commits = cli_util::resolve_all_revs(&workspace_command, ui, &args.revisions)?
         .into_iter()
         .collect_vec();
     let target_ids = target_commits.iter().map(|c| c.id().clone()).collect_vec();

cli/src/commands/rebase.rs

@@ -27,8 +27,8 @@ use jj_lib::settings::UserSettings;
 use tracing::instrument;
 
 use crate::cli_util::{
-    resolve_multiple_nonempty_revsets_default_single, short_commit_hash, user_error, CommandError,
-    CommandHelper, RevisionArg, WorkspaceCommandHelper,
+    self, resolve_multiple_nonempty_revsets_default_single, short_commit_hash, user_error,
+    CommandError, CommandHelper, RevisionArg, WorkspaceCommandHelper,
 };
 use crate::ui::Ui;
 
@@ -161,7 +161,7 @@ Please use `jj rebase -d 'all:x|y'` instead of `jj rebase --allow-large-revsets
         ));
     }
     let mut workspace_command = command.workspace_helper(ui)?;
-    let new_parents = resolve_destination_revs(&workspace_command, ui, &args.destination)?
+    let new_parents = cli_util::resolve_all_revs(&workspace_command, ui, &args.destination)?
         .into_iter()
         .collect_vec();
     if let Some(rev_str) = &args.revision {
@@ -390,20 +390,3 @@ fn check_rebase_destinations(
     }
     Ok(())
 }
-
-/// Resolves revsets into revisions to rebase onto. These revisions don't have
-/// to be rewriteable.
-pub(crate) fn resolve_destination_revs(
-    workspace_command: &WorkspaceCommandHelper,
-    ui: &mut Ui,
-    revisions: &[RevisionArg],
-) -> Result<IndexSet<Commit>, CommandError> {
-    let commits =
-        resolve_multiple_nonempty_revsets_default_single(workspace_command, ui, revisions)?;
-    let root_commit_id = workspace_command.repo().store().root_commit_id();
-    if commits.len() >= 2 && commits.iter().any(|c| c.id() == root_commit_id) {
-        Err(user_error("Cannot merge with root revision"))
-    } else {
-        Ok(commits)
-    }
-}

cli/src/commands/workspace.rs

@@ -27,7 +27,7 @@ use jj_lib::workspace::{default_working_copy_initializer, Workspace};
 use tracing::instrument;
 
 use crate::cli_util::{
-    check_stale_working_copy, print_checkout_stats, user_error, CommandError, CommandHelper,
+    self, check_stale_working_copy, print_checkout_stats, user_error, CommandError, CommandHelper,
     RevisionArg, WorkspaceCommandHelper,
 };
 use crate::ui::Ui;
@@ -61,10 +61,20 @@ pub(crate) struct WorkspaceAddArgs {
     /// directory.
     #[arg(long)]
     name: Option<String>,
-    /// The revision that the workspace should be created at; a new working copy
-    /// commit will be created on top of it.
+    /// A list of parent revisions for the working-copy commit of the newly
+    /// created workspace. You may specify nothing, or any number of parents.
+    ///
+    /// If no revisions are specified, the new workspace will be created, and
+    /// its working-copy commit will exist on top of the parent(s) of the
+    /// working-copy commit in the current workspace, i.e. they will share the
+    /// same parent(s).
+    ///
+    /// If any revisions are specified, the new workspace will be created, and
+    /// the new working-copy commit will be created with all these revisions as
+    /// parents, i.e. the working-copy commit will exist as if you had run `jj
+    /// new r1 r2 r3 ...`.
     #[arg(long, short)]
-    revision: Option<RevisionArg>,
+    revision: Vec<RevisionArg>,
 }
 
 /// Stop tracking a workspace's working-copy commit in the repo
@@ -167,9 +177,9 @@ fn cmd_workspace_add(
         &name
     ));
 
-    let parents = if let Some(specific_rev) = &args.revision {
-        vec![old_workspace_command.resolve_single_rev(specific_rev, ui)?]
-    } else {
+    // If no parent revisions are specified, create a working-copy commit based
+    // on the parent of the current working-copy commit.
+    let parents = if args.revision.is_empty() {
         // Check out parents of the current workspace's working-copy commit, or the
         // root if there is no working-copy commit in the current workspace.
         if let Some(old_wc_commit_id) = tx
@@ -181,6 +191,10 @@ fn cmd_workspace_add(
         } else {
             vec![tx.repo().store().root_commit()]
         }
+    } else {
+        cli_util::resolve_all_revs(&old_workspace_command, ui, &args.revision)?
+            .into_iter()
+            .collect_vec()
     };
 
     let tree = merge_commit_trees(tx.repo(), &parents)?;

cli/tests/test_workspaces.rs

@@ -164,6 +164,72 @@ fn test_workspaces_add_workspace_at_revision() {
     "###);
 }
 
+/// Test multiple `-r` flags to `workspace add` to create a workspace
+/// working-copy commit with multiple parents.
+#[test]
+fn test_workspaces_add_workspace_multiple_revisions() {
+    let test_env = TestEnvironment::default();
+    test_env.jj_cmd_ok(test_env.env_root(), &["init", "--git", "main"]);
+    let main_path = test_env.env_root().join("main");
+
+    std::fs::write(main_path.join("file-1"), "contents").unwrap();
+    test_env.jj_cmd_ok(&main_path, &["commit", "-m", "first"]);
+    test_env.jj_cmd_ok(&main_path, &["new", "-r", "root()"]);
+
+    std::fs::write(main_path.join("file-2"), "contents").unwrap();
+    test_env.jj_cmd_ok(&main_path, &["commit", "-m", "second"]);
+    test_env.jj_cmd_ok(&main_path, &["new", "-r", "root()"]);
+
+    std::fs::write(main_path.join("file-3"), "contents").unwrap();
+    test_env.jj_cmd_ok(&main_path, &["commit", "-m", "third"]);
+    test_env.jj_cmd_ok(&main_path, &["new", "-r", "root()"]);
+
+    insta::assert_snapshot!(get_log_output(&test_env, &main_path), @r###"
+    @  5b36783cd11c4607a329c5e8c2fd9097c9ce2add
+    │ ◉  23881f07b53ce1ea936ca8842e344dea9c3356e5
+    ├─╯
+    │ ◉  1f6a15f0af2a985703864347f5fdf27a82fc3d73
+    ├─╯
+    │ ◉  e7d7dbb91c5a543ea680711093e689916d5f31df
+    ├─╯
+    ◉  0000000000000000000000000000000000000000
+    "###);
+
+    let (_, stderr) = test_env.jj_cmd_ok(
+        &main_path,
+        &[
+            "workspace",
+            "add",
+            "--name=merge",
+            "../merged",
+            "-r=238",
+            "-r=1f6",
+            "-r=e7d",
+        ],
+    );
+    insta::assert_snapshot!(stderr.replace('\\', "/"), @r###"
+    Created workspace in "../merged"
+    Working copy now at: wmwvqwsz fa8fdc28 (empty) (no description set)
+    Parent commit      : mzvwutvl 23881f07 third
+    Parent commit      : kkmpptxz 1f6a15f0 second
+    Parent commit      : qpvuntsm e7d7dbb9 first
+    Added 3 files, modified 0 files, removed 0 files
+    "###);
+
+    insta::assert_snapshot!(get_log_output(&test_env, &main_path), @r###"
+    ◉      fa8fdc28af12d3c96b1e0ed062f5a8f9a99818f0 merge@
+    ├─┬─╮
+    │ │ ◉  e7d7dbb91c5a543ea680711093e689916d5f31df
+    │ ◉ │  1f6a15f0af2a985703864347f5fdf27a82fc3d73
+    │ ├─╯
+    ◉ │  23881f07b53ce1ea936ca8842e344dea9c3356e5
+    ├─╯
+    │ @  5b36783cd11c4607a329c5e8c2fd9097c9ce2add default@
+    ├─╯
+    ◉  0000000000000000000000000000000000000000
+    "###);
+}
+
 /// Test making changes to the working copy in a workspace as it gets rewritten
 /// from another workspace
 #[test]