cli: add a jj debug tree command for printing the tree

I'm about to make conflicts also get materialized in executable
files. We'll lose some of the test coverage in `test_chmod_command.rs`
then, because the those tests rely on the materialized content to
describe the executable bits. So this commit adds a debug command for
printing tree values and uses that in the tests.

cli/src/commands/debug.rs

@@ -23,7 +23,7 @@ use jj_lib::local_working_copy::{LocalWorkingCopy, LockedLocalWorkingCopy};
 use jj_lib::revset;
 use jj_lib::working_copy::WorkingCopy;
 
-use crate::cli_util::{resolve_op_for_load, user_error, CommandError, CommandHelper};
+use crate::cli_util::{resolve_op_for_load, user_error, CommandError, CommandHelper, RevisionArg};
 use crate::template_parser;
 use crate::ui::Ui;
 
@@ -40,6 +40,7 @@ pub enum DebugCommands {
     ReIndex(DebugReIndexArgs),
     #[command(visible_alias = "view")]
     Operation(DebugOperationArgs),
+    Tree(DebugTreeArgs),
     #[command(subcommand)]
     Watchman(DebugWatchmanSubcommand),
 }
@@ -89,6 +90,15 @@ pub enum DebugOperationDisplay {
     All,
 }
 
+/// List the recursive entries of a tree.
+#[derive(clap::Args, Clone, Debug)]
+pub struct DebugTreeArgs {
+    #[arg(long, short = 'r', default_value = "@")]
+    revision: RevisionArg,
+    paths: Vec<String>,
+    // TODO: Add an option to include trees that are ancestors of the matched paths
+}
+
 #[derive(Subcommand, Clone, Debug)]
 pub enum DebugWatchmanSubcommand {
     QueryClock,
@@ -198,6 +208,7 @@ pub fn cmd_debug(
                 writeln!(ui.stdout(), "{:#?}", op.view()?.store_view())?;
             }
         }
+        DebugCommands::Tree(sub_args) => cmd_debug_tree(ui, command, sub_args)?,
         DebugCommands::Watchman(watchman_subcommand) => {
             cmd_debug_watchman(ui, command, watchman_subcommand)?;
         }
@@ -242,6 +253,23 @@ fn cmd_debug_revset(
     Ok(())
 }
 
+fn cmd_debug_tree(
+    ui: &mut Ui,
+    command: &CommandHelper,
+    args: &DebugTreeArgs,
+) -> Result<(), CommandError> {
+    let workspace_command = command.workspace_helper(ui)?;
+    let commit = workspace_command.resolve_single_rev(&args.revision, ui)?;
+    let tree = commit.tree()?;
+    let matcher = workspace_command.matcher_from_values(&args.paths)?;
+    for (path, value) in tree.entries_matching(matcher.as_ref()) {
+        let ui_path = workspace_command.format_file_path(&path);
+        writeln!(ui.stdout(), "{ui_path}: {value:?}")?;
+    }
+
+    Ok(())
+}
+
 #[cfg(feature = "watchman")]
 fn cmd_debug_watchman(
     ui: &mut Ui,

cli/tests/test_chmod_command.rs

@@ -65,6 +65,11 @@ fn test_chmod_regular_conflict() {
     ◉  base
     ◉
     "###);
+    let stdout = test_env.jj_cmd_success(&repo_path, &["debug", "tree"]);
+    insta::assert_snapshot!(stdout, 
+    @r###"
+    file: Conflicted { removes: [Some(File { id: FileId("df967b96a579e45a18b8251732d16804b2e56a55"), executable: false })], adds: [Some(File { id: FileId("587be6b4c3f93f93c489c0111bba5596147a26cb"), executable: true }), Some(File { id: FileId("8ba3a16384aacc37d01564b28401755ce8053f51"), executable: false })] }
+    "###);
     let stdout = test_env.jj_cmd_success(&repo_path, &["cat", "file"]);
     insta::assert_snapshot!(stdout, 
     @r###"
@@ -76,6 +81,11 @@ fn test_chmod_regular_conflict() {
 
     // Test chmodding a conflict
     test_env.jj_cmd_ok(&repo_path, &["chmod", "x", "file"]);
+    let stdout = test_env.jj_cmd_success(&repo_path, &["debug", "tree"]);
+    insta::assert_snapshot!(stdout, 
+    @r###"
+    file: Conflicted { removes: [Some(File { id: FileId("df967b96a579e45a18b8251732d16804b2e56a55"), executable: true })], adds: [Some(File { id: FileId("587be6b4c3f93f93c489c0111bba5596147a26cb"), executable: true }), Some(File { id: FileId("8ba3a16384aacc37d01564b28401755ce8053f51"), executable: true })] }
+    "###);
     let stdout = test_env.jj_cmd_success(&repo_path, &["cat", "file"]);
     insta::assert_snapshot!(stdout, 
     @r###"
@@ -85,6 +95,11 @@ fn test_chmod_regular_conflict() {
       Adding executable file with id 8ba3a16384aacc37d01564b28401755ce8053f51
     "###);
     test_env.jj_cmd_ok(&repo_path, &["chmod", "n", "file"]);
+    let stdout = test_env.jj_cmd_success(&repo_path, &["debug", "tree"]);
+    insta::assert_snapshot!(stdout, 
+    @r###"
+    file: Conflicted { removes: [Some(File { id: FileId("df967b96a579e45a18b8251732d16804b2e56a55"), executable: false })], adds: [Some(File { id: FileId("587be6b4c3f93f93c489c0111bba5596147a26cb"), executable: false }), Some(File { id: FileId("8ba3a16384aacc37d01564b28401755ce8053f51"), executable: false })] }
+    "###);
     let stdout = test_env.jj_cmd_success(&repo_path, &["cat", "file"]);
     insta::assert_snapshot!(stdout, 
     @r###"
@@ -103,6 +118,11 @@ fn test_chmod_regular_conflict() {
     insta::assert_snapshot!(stderr, @r###"
     Error: No such path at 'nonexistent'.
     "###);
+    let stdout = test_env.jj_cmd_success(&repo_path, &["debug", "tree"]);
+    insta::assert_snapshot!(stdout, 
+    @r###"
+    file: Conflicted { removes: [Some(File { id: FileId("df967b96a579e45a18b8251732d16804b2e56a55"), executable: false })], adds: [Some(File { id: FileId("587be6b4c3f93f93c489c0111bba5596147a26cb"), executable: false }), Some(File { id: FileId("8ba3a16384aacc37d01564b28401755ce8053f51"), executable: false })] }
+    "###);
     let stdout = test_env.jj_cmd_success(&repo_path, &["cat", "file"]);
     insta::assert_snapshot!(stdout, 
     @r###"
@@ -161,6 +181,11 @@ fn test_chmod_file_dir_deletion_conflicts() {
     "###);
 
     // The file-dir conflict cannot be chmod-ed
+    let stdout = test_env.jj_cmd_success(&repo_path, &["debug", "tree", "-r=file_dir"]);
+    insta::assert_snapshot!(stdout,
+    @r###"
+    file: Conflicted { removes: [Some(File { id: FileId("df967b96a579e45a18b8251732d16804b2e56a55"), executable: false })], adds: [Some(File { id: FileId("78981922613b2afb6025042ff6bd878ac1994e85"), executable: false }), Some(Tree(TreeId("133bb38fc4e4bf6b551f1f04db7e48f04cac2877")))] }
+    "###);
     let stdout = test_env.jj_cmd_success(&repo_path, &["cat", "-r=file_dir", "file"]);
     insta::assert_snapshot!(stdout,
     @r###"
@@ -175,6 +200,11 @@ fn test_chmod_file_dir_deletion_conflicts() {
     "###);
 
     // The file_deletion conflict can be chmod-ed
+    let stdout = test_env.jj_cmd_success(&repo_path, &["debug", "tree", "-r=file_deletion"]);
+    insta::assert_snapshot!(stdout,
+    @r###"
+    file: Conflicted { removes: [Some(File { id: FileId("df967b96a579e45a18b8251732d16804b2e56a55"), executable: false })], adds: [Some(File { id: FileId("78981922613b2afb6025042ff6bd878ac1994e85"), executable: false }), None] }
+    "###);
     let stdout = test_env.jj_cmd_success(&repo_path, &["cat", "-r=file_deletion", "file"]);
     insta::assert_snapshot!(stdout,
     @r###"
@@ -189,11 +219,16 @@ fn test_chmod_file_dir_deletion_conflicts() {
         test_env.jj_cmd_ok(&repo_path, &["chmod", "x", "file", "-r=file_deletion"]);
     insta::assert_snapshot!(stdout, @"");
     insta::assert_snapshot!(stderr, @r###"
-    Working copy now at: kmkuslsw 8b70a1d2 file_deletion | (conflict) file_deletion
+    Working copy now at: kmkuslsw 4cc432b5 file_deletion | (conflict) file_deletion
     Parent commit      : zsuskuln c51c9c55 file | file
     Parent commit      : royxmykx 6b18b3c1 deletion | deletion
     Added 0 files, modified 1 files, removed 0 files
     "###);
+    let stdout = test_env.jj_cmd_success(&repo_path, &["debug", "tree", "-r=file_deletion"]);
+    insta::assert_snapshot!(stdout,
+    @r###"
+    file: Conflicted { removes: [Some(File { id: FileId("df967b96a579e45a18b8251732d16804b2e56a55"), executable: true })], adds: [Some(File { id: FileId("78981922613b2afb6025042ff6bd878ac1994e85"), executable: true }), None] }
+    "###);
     let stdout = test_env.jj_cmd_success(&repo_path, &["cat", "-r=file_deletion", "file"]);
     insta::assert_snapshot!(stdout,
     @r###"