cli: support filtering by paths in status

CHANGELOG.md

@@ -65,6 +65,9 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 * new function `working_copies()` for revsets to show the working copy commits of all workspaces.
 
+* `jj status` now supports filtering by paths. For example, `jj status .` will
+  only list changed files that are descendants of the current directory.
+
 ### Fixed bugs
 
 ## [0.15.1] - 2024-03-06

cli/src/commands/status.rs

@@ -13,7 +13,6 @@
 // limitations under the License.
 
 use itertools::Itertools;
-use jj_lib::matchers::EverythingMatcher;
 use jj_lib::repo::Repo;
 use jj_lib::rewrite::merge_commit_trees;
 use tracing::instrument;
@@ -34,20 +33,25 @@ use crate::ui::Ui;
 ///  * Conflicted branches (see https://github.com/martinvonz/jj/blob/main/docs/branches.md)
 #[derive(clap::Args, Clone, Debug)]
 #[command(visible_alias = "st")]
-pub(crate) struct StatusArgs {}
+pub(crate) struct StatusArgs {
+    /// Restrict the status display to these paths
+    #[arg(value_hint = clap::ValueHint::AnyPath)]
+    paths: Vec<String>,
+}
 
 #[instrument(skip_all)]
 pub(crate) fn cmd_status(
     ui: &mut Ui,
     command: &CommandHelper,
-    _args: &StatusArgs,
+    args: &StatusArgs,
 ) -> Result<(), CommandError> {
     let workspace_command = command.workspace_helper(ui)?;
     let repo = workspace_command.repo();
     let maybe_wc_commit = workspace_command
         .get_wc_commit_id()
         .map(|id| repo.store().get_commit(id))
         .transpose()?;
+    let matcher = workspace_command.matcher_from_values(&args.paths)?;
     ui.request_pager();
     let mut formatter = ui.stdout_formatter();
     let formatter = formatter.as_mut();
@@ -62,10 +66,12 @@ pub(crate) fn cmd_status(
             diff_util::show_diff_summary(
                 formatter,
                 &workspace_command,
-                parent_tree.diff_stream(&tree, &EverythingMatcher),
+                parent_tree.diff_stream(&tree, matcher.as_ref()),
             )?;
         }
 
+        // TODO: Conflicts should also be filtered by the `matcher`. See the related TODO on
+        // `MergedTree::conflicts()`.
         let conflicts = wc_commit.tree()?.conflicts().collect_vec();
         if !conflicts.is_empty() {
             writeln!(

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

@@ -1741,7 +1741,11 @@ This includes:
 
 * Conflicted branches (see https://github.com/martinvonz/jj/blob/main/docs/branches.md)
 
-**Usage:** `jj status`
+**Usage:** `jj status [PATHS]...`
+
+###### **Arguments:**
+
+* `<PATHS>` — Restrict the status display to these paths
 
 
 

cli/tests/test_status_command.rs

@@ -62,3 +62,22 @@ fn test_status_ignored_gitignore() {
     Parent commit: zzzzzzzz 00000000 (empty) (no description set)
     "###);
 }
+
+#[test]
+fn test_status_filtered() {
+    let test_env = TestEnvironment::default();
+    test_env.jj_cmd_ok(test_env.env_root(), &["init", "repo", "--git"]);
+    let repo_path = test_env.env_root().join("repo");
+
+    std::fs::write(repo_path.join("file_1"), "file_1").unwrap();
+    std::fs::write(repo_path.join("file_2"), "file_2").unwrap();
+
+    // The output filtered to file_1 should not list the addition of file_2.
+    let stdout = test_env.jj_cmd_success(&repo_path, &["status", "file_1"]);
+    insta::assert_snapshot!(stdout, @r###"
+    Working copy changes:
+    A file_1
+    Working copy : qpvuntsm abcaaacd (no description set)
+    Parent commit: zzzzzzzz 00000000 (empty) (no description set)
+    "###);
+}