feat(split): add --detach flag

Author: claytonrcarter

git-branchless-opts/src/lib.rs

@@ -660,9 +660,17 @@ pub enum Command {
         #[clap(value_parser, required = true)]
         files: Vec<String>,
 
+        /// Restack any descendents onto the split commit, not the extracted commit.
+        #[clap(action, short = 'd', long = "detach")]
+        detach: bool,
+
         /// Options for resolving revset expressions.
         #[clap(flatten)]
         resolve_revset_options: ResolveRevsetOptions,
+
+        /// Options for moving commits.
+        #[clap(flatten)]
+        move_options: MoveOptions,
     },
 
     /// Push commits to a remote.

git-branchless/src/commands/mod.rs

@@ -181,14 +181,18 @@ fn command_main(ctx: CommandContext, opts: Opts) -> EyreExitOr<()> {
         },
 
         Command::Split {
+            detach,
             files,
             resolve_revset_options,
             revset,
+            move_options,
         } => split::split(
             &effects,
             revset,
             &resolve_revset_options,
             files,
+            detach,
+            &move_options,
             &git_run_info,
         )?,
 

git-branchless/src/commands/split.rs

@@ -8,7 +8,7 @@ use std::{
     time::{SystemTime, UNIX_EPOCH},
 };
 
-use git_branchless_opts::{ResolveRevsetOptions, Revset};
+use git_branchless_opts::{MoveOptions, ResolveRevsetOptions, Revset};
 use git_branchless_revset::resolve_commits;
 use lib::{
     core::{
@@ -41,6 +41,8 @@ pub fn split(
     revset: Revset,
     resolve_revset_options: &ResolveRevsetOptions,
     files_to_extract: Vec<String>,
+    detach: bool,
+    move_options: &MoveOptions,
     git_run_info: &GitRunInfo,
 ) -> EyreExitOr<()> {
     let repo = Repo::from_current_dir()?;
@@ -61,6 +63,16 @@ pub fn split(
     let pool = ThreadPoolBuilder::new().build()?;
     let repo_pool = RepoResource::new_pool(&repo)?;
 
+    let MoveOptions {
+        force_rewrite_public_commits,
+        force_in_memory,
+        force_on_disk,
+        detect_duplicate_commits_via_patch_id,
+        resolve_merge_conflicts,
+        dump_rebase_constraints,
+        dump_rebase_plan,
+    } = *move_options;
+
     let commit_to_split_oid: NonZeroOid = match resolve_commits(
         effects,
         &repo,
@@ -89,10 +101,10 @@ pub fn split(
     let permissions = match RebasePlanPermissions::verify_rewrite_set(
         &dag,
         BuildRebasePlanOptions {
-            force_rewrite_public_commits: false,
-            dump_rebase_constraints: false,
-            dump_rebase_plan: false,
-            detect_duplicate_commits_via_patch_id: false,
+            force_rewrite_public_commits,
+            dump_rebase_constraints,
+            dump_rebase_plan,
+            detect_duplicate_commits_via_patch_id,
         },
         &vec![commit_to_split_oid].into_iter().collect(),
     )? {
@@ -268,14 +280,24 @@ pub fn split(
         commit_oid: extracted_commit_oid,
     }])?;
 
+    // push the new commits into the dag for the rebase planner
+    dag.sync_from_oids(
+        effects,
+        &repo,
+        CommitSet::empty(),
+        vec![split_commit_oid, extracted_commit_oid]
+            .into_iter()
+            .collect(),
+    )?;
+
     let head_info = repo.get_head_info()?;
     let (checkout_target, rewritten_oids) = match head_info {
         // branch @ split commit checked out: extend branch to include extracted
         // commit; branch will stay checked out w/o any explicit checkout
         ResolvedReferenceInfo {
             oid: Some(oid),
             reference_name: Some(_),
-        } if oid == commit_to_split_oid => (
+        } if oid == commit_to_split_oid && !detach => (
             None,
             vec![(
                 commit_to_split_oid,
@@ -331,7 +353,11 @@ pub fn split(
     let mut builder = RebasePlanBuilder::new(&dag, permissions);
     let children = dag.query_children(CommitSet::from(commit_to_split_oid))?;
     for child in dag.commit_set_to_vec(&children)? {
-        builder.move_subtree(child, vec![extracted_commit_oid])?;
+        if detach {
+            builder.move_subtree(child, vec![split_commit_oid])?;
+        } else {
+            builder.move_subtree(child, vec![extracted_commit_oid])?;
+        }
     }
     let rebase_plan = builder.build(effects, &pool, &repo_pool)?;
 
@@ -345,9 +371,9 @@ pub fn split(
                 now,
                 event_tx_id,
                 preserve_timestamps: get_restack_preserve_timestamps(&repo)?,
-                force_in_memory: true,
-                force_on_disk: false,
-                resolve_merge_conflicts: false,
+                force_in_memory,
+                force_on_disk,
+                resolve_merge_conflicts,
                 check_out_commit_options: CheckOutCommitOptions {
                     additional_args: Default::default(),
                     force_detach: false,

git-branchless/tests/test_split.rs

@@ -439,6 +439,69 @@ fn test_split_restacks_descendents() -> eyre::Result<()> {
     Ok(())
 }
 
+#[test]
+fn test_split_detach() -> eyre::Result<()> {
+    let git = make_git()?;
+    git.init_repo()?;
+    git.detach_head()?;
+
+    git.write_file_txt("test1", "contents1")?;
+    git.write_file_txt("test2", "contents2")?;
+    git.write_file_txt("test3", "contents3")?;
+    git.run(&["add", "."])?;
+    git.run(&["commit", "-m", "first commit"])?;
+
+    git.commit_file("test3", 1)?;
+
+    {
+        let (stdout, _stderr) = git.branchless("smartlog", &[])?;
+        insta::assert_snapshot!(stdout, @r###"
+        O f777ecc (master) create initial.txt
+        |
+        o e48cdc5 first commit
+        |
+        @ 3d220e0 create test3.txt
+        "###);
+    }
+
+    {
+        let (stdout, _stderr) = git.branchless("split", &["HEAD~", "test2.txt", "--detach"])?;
+        insta::assert_snapshot!(&stdout, @r###"
+            Attempting rebase in-memory...
+            [1/1] Committed as: f88fbe5 create test3.txt
+            branchless: processing 1 rewritten commit
+            branchless: running command: <git-executable> checkout f88fbe5901493ffe1c669cdb8aa5f056dc0bb605
+            In-memory rebase succeeded.
+            O f777ecc (master) create initial.txt
+            |
+            o 2932db7 first commit
+            |\
+            | o 01523cc temp(split): test2.txt (+1)
+            |
+            @ f88fbe5 create test3.txt
+        "###);
+    }
+
+    {
+        let (stdout, _stderr) = git.run(&["show", "--pretty=format:", "--stat", "HEAD~"])?;
+        insta::assert_snapshot!(&stdout, @"
+            test1.txt | 1 +
+            test3.txt | 1 +
+            2 files changed, 2 insertions(+)
+        ");
+
+        let (split_commit, _stderr) = git.run(&["query", "--raw", "exactly(siblings(HEAD), 1)"])?;
+        let (stdout, _stderr) =
+            git.run(&["show", "--pretty=format:", "--stat", split_commit.trim()])?;
+        insta::assert_snapshot!(&stdout, @"
+            test2.txt | 1 +
+            1 file changed, 1 insertion(+)
+        ");
+    }
+
+    Ok(())
+}
+
 #[test]
 fn test_split_undo_works() -> eyre::Result<()> {
     let git = make_git()?;