feat: implement basic split command

Author: claytonrcarter

git-branchless-lib/src/git/mod.rs

@@ -34,4 +34,6 @@ pub use test::{
     make_test_command_slug, SerializedNonZeroOid, SerializedTestResult, TestCommand,
     TEST_ABORT_EXIT_CODE, TEST_INDETERMINATE_EXIT_CODE, TEST_SUCCESS_EXIT_CODE,
 };
-pub use tree::{dehydrate_tree, get_changed_paths_between_trees, hydrate_tree, Tree};
+pub use tree::{
+    dehydrate_tree, get_changed_paths_between_trees, hydrate_tree, make_empty_tree, Tree,
+};

git-branchless-lib/src/git/status.rs

@@ -88,6 +88,20 @@ impl From<git2::FileMode> for FileMode {
     }
 }
 
+impl From<FileMode> for git2::FileMode {
+    fn from(file_mode: FileMode) -> Self {
+        match file_mode {
+            FileMode::Blob => git2::FileMode::Blob,
+            FileMode::BlobExecutable => git2::FileMode::BlobExecutable,
+            FileMode::BlobGroupWritable => git2::FileMode::BlobGroupWritable,
+            FileMode::Commit => git2::FileMode::Commit,
+            FileMode::Link => git2::FileMode::Link,
+            FileMode::Tree => git2::FileMode::Tree,
+            FileMode::Unreadable => git2::FileMode::Unreadable,
+        }
+    }
+}
+
 impl From<i32> for FileMode {
     fn from(file_mode: i32) -> Self {
         if file_mode == i32::from(git2::FileMode::Blob) {

git-branchless-lib/src/git/tree.rs

@@ -3,6 +3,7 @@ use std::fmt::Debug;
 use std::path::{Path, PathBuf};
 
 use bstr::ByteVec;
+use git2::build::TreeUpdateBuilder;
 use itertools::Itertools;
 use thiserror::Error;
 use tracing::{instrument, warn};
@@ -116,6 +117,31 @@ impl Tree<'_> {
             .map(|maybe_entry| maybe_entry.map(|entry| entry.inner.id().into()))
     }
 
+    /// Remove the given path from the Tree, creating a new Tree in the given repo.
+    pub fn remove(&self, repo: &Repo, path: &Path) -> Result<NonZeroOid> {
+        let mut builder = TreeUpdateBuilder::new();
+        let tree_oid = builder
+            .remove(path)
+            .create_updated(&repo.inner, &self.inner)
+            .map_err(Error::BuildTree)?;
+        Ok(make_non_zero_oid(tree_oid))
+    }
+
+    /// Add or replace the given path/entry from the Tree, creating a new Tree in the given repo.
+    pub fn add_or_replace(
+        &self,
+        repo: &Repo,
+        path: &Path,
+        entry: &TreeEntry,
+    ) -> Result<NonZeroOid> {
+        let mut builder = TreeUpdateBuilder::new();
+        let tree_oid = builder
+            .upsert(path, entry.get_oid().into(), entry.get_filemode().into())
+            .create_updated(&repo.inner, &self.inner)
+            .map_err(Error::BuildTree)?;
+        Ok(make_non_zero_oid(tree_oid))
+    }
+
     /// Get the (top-level) list of paths in this tree, for testing.
     pub fn get_entry_paths_for_testing(&self) -> impl Debug {
         self.inner
@@ -456,6 +482,7 @@ pub fn hydrate_tree(
     Ok(make_non_zero_oid(tree_oid))
 }
 
+/// Create a new, empty tree.
 pub fn make_empty_tree(repo: &Repo) -> Result<Tree> {
     let tree_oid = hydrate_tree(repo, None, Default::default())?;
     repo.find_tree_or_fail(tree_oid)

git-branchless-lib/src/testing.rs

@@ -81,6 +81,9 @@ pub struct GitRunOptions {
 
     /// Additional environment variables to start the process with.
     pub env: HashMap<String, String>,
+
+    /// Subdirectory of repo to use as working directory.
+    pub subdir: Option<PathBuf>,
 }
 
 impl Git {
@@ -217,8 +220,14 @@ impl Git {
             expected_exit_code,
             input,
             env,
+            subdir,
         } = options;
 
+        let current_dir = subdir.as_ref().map_or(self.repo_path.clone(), |subdir| {
+            let mut p = self.repo_path.clone();
+            p.push(subdir);
+            p
+        });
         let env: BTreeMap<_, _> = self
             .get_base_env(*time)
             .into_iter()
@@ -229,7 +238,7 @@ impl Git {
             .collect();
         let mut command = Command::new(&self.path_to_git);
         command
-            .current_dir(&self.repo_path)
+            .current_dir(&current_dir)
             .args(args)
             .env_clear()
             .envs(&env);

git-branchless-opts/src/lib.rs

@@ -652,6 +652,25 @@ pub enum Command {
         subcommand: SnapshotSubcommand,
     },
 
+    /// Split commits.
+    Split {
+        /// Commit to split. If a revset is given, it must resolve to a single commit.
+        #[clap(value_parser)]
+        revset: Revset,
+
+        /// Files to extract from the commit.
+        #[clap(value_parser, required = true)]
+        files: Vec<String>,
+
+        /// 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.
     Submit(SubmitArgs),
 

git-branchless/Cargo.toml

@@ -111,6 +111,9 @@ name = "test_reword"
 [[test]]
 name = "test_snapshot"
 
+[[test]]
+name = "test_split"
+
 [[test]]
 name = "test_sync"
 

git-branchless/src/commands/mod.rs

@@ -6,6 +6,7 @@ mod hide;
 mod repair;
 mod restack;
 mod snapshot;
+mod split;
 mod sync;
 mod wrap;
 
@@ -179,6 +180,20 @@ fn command_main(ctx: CommandContext, opts: Opts) -> EyreExitOr<()> {
             }
         },
 
+        Command::Split {
+            files,
+            resolve_revset_options,
+            revset,
+            move_options,
+        } => split::split(
+            &effects,
+            revset,
+            &resolve_revset_options,
+            files,
+            &move_options,
+            &git_run_info,
+        )?,
+
         Command::Submit(args) => git_branchless_submit::command_main(ctx, args)?,
 
         Command::Sync {