git clone: Add depth argument

CHANGELOG.md

@@ -136,6 +136,9 @@ to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 * Initial support for shallow git repositories has been implemented. However
   deepening the history of a shallow repository is not yet supported.
 
+* `jj git clone` now accepts a `--depth <DEPTH>` option, which
+  allows to clone the repository with a given depth.
+
 ### Fixed bugs
 
 * Update working copy before reporting changes. This prevents errors during reporting

cli/src/commands/git/clone.rs

@@ -15,6 +15,7 @@
 use std::fs;
 use std::io;
 use std::io::Write;
+use std::num::NonZeroU32;
 use std::path::Path;
 use std::path::PathBuf;
 
@@ -60,6 +61,9 @@ pub struct GitCloneArgs {
     /// Whether or not to colocate the Jujutsu repo with the git repo
     #[arg(long)]
     colocate: bool,
+    /// Create a shallow clone of the given depth
+    #[arg(long)]
+    depth: Option<NonZeroU32>,
 }
 
 fn absolute_git_source(cwd: &Path, source: &str) -> String {
@@ -132,6 +136,7 @@ pub fn cmd_git_clone(
         ui,
         command,
         args.colocate,
+        args.depth,
         remote_name,
         &source,
         &canonical_wc_path,
@@ -195,6 +200,7 @@ fn do_git_clone(
     ui: &mut Ui,
     command: &CommandHelper,
     colocate: bool,
+    depth: Option<NonZeroU32>,
     remote_name: &str,
     source: &str,
     wc_path: &Path,
@@ -223,6 +229,7 @@ fn do_git_clone(
             &[StringPattern::everything()],
             cb,
             &command.settings().git_settings(),
+            depth,
         )
     })
     .map_err(|err| match err {

cli/src/commands/git/fetch.rs

@@ -78,6 +78,7 @@ pub fn cmd_git_fetch(
                 &args.branch,
                 cb,
                 &command.settings().git_settings(),
+                None,
             )
         })
         .map_err(|err| match err {

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

@@ -984,6 +984,7 @@ The Git repo will be a bare git repo stored inside the `.jj/` directory.
 
   Default value: `origin`
 * `--colocate` — Whether or not to colocate the Jujutsu repo with the git repo
+* `--depth <DEPTH>` — Create a shallow clone of the given depth
 
 
 

cli/tests/test_git_clone.rs

@@ -557,6 +557,26 @@ fn test_git_clone_trunk_deleted() {
     "#);
 }
 
+#[test]
+fn test_git_clone_with_depth() {
+    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_non_empty_git_repo(&git_repo);
+
+    // local transport does not support shallow clones so we just test that the
+    // depth arg is passed on here
+    let stderr = test_env.jj_cmd_failure(
+        test_env.env_root(),
+        &["git", "clone", "--depth", "1", "source", "clone"],
+    );
+    insta::assert_snapshot!(stderr, @r#"
+    Fetching into new repo in "$TEST_ENV/clone"
+    Error: shallow fetch is not supported by the local transport; class=Net (12)
+    "#);
+}
+
 fn get_bookmark_output(test_env: &TestEnvironment, repo_path: &Path) -> String {
     test_env.jj_cmd_success(repo_path, &["bookmark", "list", "--all-remotes"])
 }

lib/src/git.rs

@@ -21,6 +21,7 @@ use std::collections::HashSet;
 use std::default::Default;
 use std::fmt;
 use std::io::Read;
+use std::num::NonZeroU32;
 use std::path::PathBuf;
 use std::str;
 
@@ -1244,6 +1245,7 @@ pub fn fetch(
     branch_names: &[StringPattern],
     callbacks: RemoteCallbacks<'_>,
     git_settings: &GitSettings,
+    depth: Option<NonZeroU32>,
 ) -> Result<GitFetchStats, GitFetchError> {
     // Perform a `git fetch` on the local git repo, updating the remote-tracking
     // branches in the git repo.
@@ -1260,6 +1262,9 @@ pub fn fetch(
     fetch_options.proxy_options(proxy_options);
     let callbacks = callbacks.into_git();
     fetch_options.remote_callbacks(callbacks);
+    if let Some(depth) = depth {
+        fetch_options.depth(depth.get().try_into().unwrap_or(i32::MAX));
+    }
     // At this point, we are only updating Git's remote tracking branches, not the
     // local branches.
     let refspecs: Vec<_> = branch_names

lib/tests/test_git.rs

@@ -2270,6 +2270,7 @@ fn test_fetch_empty_repo() {
         &[StringPattern::everything()],
         git::RemoteCallbacks::default(),
         &git_settings,
+        None,
     )
     .unwrap();
     // No default bookmark and no refs
@@ -2296,6 +2297,7 @@ fn test_fetch_initial_commit() {
         &[StringPattern::everything()],
         git::RemoteCallbacks::default(),
         &git_settings,
+        None,
     )
     .unwrap();
     // No default bookmark because the origin repo's HEAD wasn't set
@@ -2346,6 +2348,7 @@ fn test_fetch_success() {
         &[StringPattern::everything()],
         git::RemoteCallbacks::default(),
         &git_settings,
+        None,
     )
     .unwrap();
     test_data.repo = tx.commit("test");
@@ -2369,6 +2372,7 @@ fn test_fetch_success() {
         &[StringPattern::everything()],
         git::RemoteCallbacks::default(),
         &git_settings,
+        None,
     )
     .unwrap();
     // The default bookmark is "main"
@@ -2426,6 +2430,7 @@ fn test_fetch_prune_deleted_ref() {
         &[StringPattern::everything()],
         git::RemoteCallbacks::default(),
         &git_settings,
+        None,
     )
     .unwrap();
     // Test the setup
@@ -2449,6 +2454,7 @@ fn test_fetch_prune_deleted_ref() {
         &[StringPattern::everything()],
         git::RemoteCallbacks::default(),
         &git_settings,
+        None,
     )
     .unwrap();
     assert_eq!(stats.import_stats.abandoned_commits, vec![jj_id(&commit)]);
@@ -2476,6 +2482,7 @@ fn test_fetch_no_default_branch() {
         &[StringPattern::everything()],
         git::RemoteCallbacks::default(),
         &git_settings,
+        None,
     )
     .unwrap();
 
@@ -2499,6 +2506,7 @@ fn test_fetch_no_default_branch() {
         &[StringPattern::everything()],
         git::RemoteCallbacks::default(),
         &git_settings,
+        None,
     )
     .unwrap();
     // There is no default bookmark
@@ -2520,6 +2528,7 @@ fn test_fetch_empty_refspecs() {
         &[],
         git::RemoteCallbacks::default(),
         &git_settings,
+        None,
     )
     .unwrap();
     assert!(tx
@@ -2546,6 +2555,7 @@ fn test_fetch_no_such_remote() {
         &[StringPattern::everything()],
         git::RemoteCallbacks::default(),
         &git_settings,
+        None,
     );
     assert!(matches!(result, Err(GitFetchError::NoSuchRemote(_))));
 }