RFD: Soften deprecation of jj checkout/merge

CHANGELOG.md

@@ -122,9 +122,6 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
   `jj checkout` and `jj merge` will no longer be shown as part of `jj help`, but
   will still function for now, emitting a warning about their deprecation.
 
-  **Deadline**: `jj checkout` and `jj merge` will be deleted and are expected
-  become a **hard error later in 2024**.
-
 * `jj init --git` and `jj init --git-repo` are now deprecated and will be removed
   in the near future.
 

cli/src/commands/checkout.rs

@@ -24,7 +24,6 @@ use crate::ui::Ui;
 /// For more information, see
 /// https://github.com/martinvonz/jj/blob/main/docs/working-copy.md.
 #[derive(clap::Args, Clone, Debug)]
-#[command(visible_aliases = &["co"])]
 pub(crate) struct CheckoutArgs {
     /// The revision to update to
     revision: RevisionArg,
@@ -47,8 +46,8 @@ pub(crate) fn cmd_checkout(
         "warning: `jj checkout` is deprecated; use `jj new` instead, which is equivalent"
     )?;
     writeln!(
-        ui.warning(),
-        "warning: `jj checkout` will be removed in a future version, and this will be a hard error"
+        ui.hint(),
+        r#"Run e.g. `jj config set --user aliases.co '["new"]'` to disable this message."#
     )?;
     let mut workspace_command = command.workspace_helper(ui)?;
     let target = workspace_command.resolve_single_rev(&args.revision)?;

cli/src/commands/merge.rs

@@ -29,10 +29,6 @@ pub(crate) fn cmd_merge(
         ui.warning(),
         "warning: `jj merge` is deprecated; use `jj new` instead, which is equivalent"
     )?;
-    writeln!(
-        ui.warning(),
-        "warning: `jj merge` will be removed in a future version, and this will be a hard error"
-    )?;
     if args.revisions.len() < 2 {
         return Err(CommandError::CliError(String::from(
             "Merge requires at least two revisions",

cli/src/config/misc.toml

@@ -1,5 +1,7 @@
+# The code assumes that this table exists, so don't delete it even if you remove
+# all aliases from here.
 [aliases]
-# Placeholder: added by user
+co = ["checkout"]
 
 [format]
 tree-level-conflicts = true

cli/tests/test_checkout.rs

@@ -30,7 +30,7 @@ fn test_checkout() {
     insta::assert_snapshot!(stdout, @"");
     insta::assert_snapshot!(stderr, @r###"
     warning: `jj checkout` is deprecated; use `jj new` instead, which is equivalent
-    warning: `jj checkout` will be removed in a future version, and this will be a hard error
+    Run e.g. `jj config set --user aliases.co '["new"]'` to disable this message.
     Working copy now at: zsuskuln 05ce7118 (empty) (no description set)
     Parent commit      : rlvkpnrz 5c52832c (empty) second
     "###);
@@ -67,7 +67,7 @@ fn test_checkout_not_single_rev() {
     let stderr = test_env.jj_cmd_failure(&repo_path, &["checkout", "root()..@"]);
     insta::assert_snapshot!(stderr, @r###"
     warning: `jj checkout` is deprecated; use `jj new` instead, which is equivalent
-    warning: `jj checkout` will be removed in a future version, and this will be a hard error
+    Run e.g. `jj config set --user aliases.co '["new"]'` to disable this message.
     Error: Revset "root()..@" resolved to more than one revision
     Hint: The revset "root()..@" resolved to these revisions:
     royxmykx 2f859371 (empty) (no description set)
@@ -81,7 +81,7 @@ fn test_checkout_not_single_rev() {
     let stderr = test_env.jj_cmd_failure(&repo_path, &["checkout", "root()..@-"]);
     insta::assert_snapshot!(stderr, @r###"
     warning: `jj checkout` is deprecated; use `jj new` instead, which is equivalent
-    warning: `jj checkout` will be removed in a future version, and this will be a hard error
+    Run e.g. `jj config set --user aliases.co '["new"]'` to disable this message.
     Error: Revset "root()..@-" resolved to more than one revision
     Hint: The revset "root()..@-" resolved to these revisions:
     mzvwutvl 5c1afd8b (empty) fifth
@@ -94,7 +94,7 @@ fn test_checkout_not_single_rev() {
     let stderr = test_env.jj_cmd_failure(&repo_path, &["checkout", "@-|@--"]);
     insta::assert_snapshot!(stderr, @r###"
     warning: `jj checkout` is deprecated; use `jj new` instead, which is equivalent
-    warning: `jj checkout` will be removed in a future version, and this will be a hard error
+    Run e.g. `jj config set --user aliases.co '["new"]'` to disable this message.
     Error: Revset "@-|@--" resolved to more than one revision
     Hint: The revset "@-|@--" resolved to these revisions:
     mzvwutvl 5c1afd8b (empty) fifth
@@ -104,7 +104,7 @@ fn test_checkout_not_single_rev() {
     let stderr = test_env.jj_cmd_failure(&repo_path, &["checkout", "none()"]);
     insta::assert_snapshot!(stderr, @r###"
     warning: `jj checkout` is deprecated; use `jj new` instead, which is equivalent
-    warning: `jj checkout` will be removed in a future version, and this will be a hard error
+    Run e.g. `jj config set --user aliases.co '["new"]'` to disable this message.
     Error: Revset "none()" didn't resolve to any revisions
     "###);
 }

cli/tests/test_diffedit_command.rs

@@ -352,7 +352,7 @@ fn test_diffedit_merge() {
     test_env.jj_cmd_ok(&repo_path, &["branch", "create", "b"]);
     std::fs::write(repo_path.join("file1"), "b\n").unwrap();
     std::fs::write(repo_path.join("file2"), "b\n").unwrap();
-    test_env.jj_cmd_ok(&repo_path, &["co", "@-"]);
+    test_env.jj_cmd_ok(&repo_path, &["new", "@-"]);
     test_env.jj_cmd_ok(&repo_path, &["new"]);
     std::fs::write(repo_path.join("file1"), "c\n").unwrap();
     std::fs::write(repo_path.join("file2"), "c\n").unwrap();

cli/tests/test_git_colocated.rs

@@ -452,7 +452,7 @@ fn test_git_colocated_checkout_non_empty_working_copy() {
     std::fs::write(workspace_root.join("two"), "y").unwrap();
 
     test_env.jj_cmd_ok(&workspace_root, &["describe", "-m", "two"]);
-    test_env.jj_cmd_ok(&workspace_root, &["co", "@-"]);
+    test_env.jj_cmd_ok(&workspace_root, &["new", "@-"]);
     let (_, stderr) = test_env.jj_cmd_ok(&workspace_root, &["describe", "-m", "new"]);
     insta::assert_snapshot!(stderr, @r###"
     Working copy now at: kkmpptxz 4c049607 (empty) new

cli/tests/test_git_push.rs

@@ -75,7 +75,7 @@ fn test_git_push_current_branch() {
         &workspace_root,
         &["describe", "branch1", "-m", "modified branch1 commit"],
     );
-    test_env.jj_cmd_ok(&workspace_root, &["co", "branch2"]);
+    test_env.jj_cmd_ok(&workspace_root, &["new", "branch2"]);
     test_env.jj_cmd_ok(&workspace_root, &["branch", "set", "branch2"]);
     test_env.jj_cmd_ok(&workspace_root, &["branch", "create", "my-branch"]);
     test_env.jj_cmd_ok(&workspace_root, &["describe", "-m", "foo"]);
@@ -149,7 +149,7 @@ fn test_git_push_no_matching_branch() {
 #[test]
 fn test_git_push_matching_branch_unchanged() {
     let (test_env, workspace_root) = set_up();
-    test_env.jj_cmd_ok(&workspace_root, &["co", "branch1"]);
+    test_env.jj_cmd_ok(&workspace_root, &["new", "branch1"]);
     let (stdout, stderr) = test_env.jj_cmd_ok(&workspace_root, &["git", "push"]);
     insta::assert_snapshot!(stdout, @"");
     insta::assert_snapshot!(stderr, @r###"

cli/tests/test_new_command.rs

@@ -122,13 +122,11 @@ fn test_new_merge() {
     let stderr = test_env.jj_cmd_cli_error(&repo_path, &["merge"]);
     insta::assert_snapshot!(stderr, @r###"
     warning: `jj merge` is deprecated; use `jj new` instead, which is equivalent
-    warning: `jj merge` will be removed in a future version, and this will be a hard error
     Error: Merge requires at least two revisions
     "###);
     let stderr = test_env.jj_cmd_cli_error(&repo_path, &["merge", "main"]);
     insta::assert_snapshot!(stderr, @r###"
     warning: `jj merge` is deprecated; use `jj new` instead, which is equivalent
-    warning: `jj merge` will be removed in a future version, and this will be a hard error
     Error: Merge requires at least two revisions
     "###);
 

cli/tests/test_next_prev_commands.rs

@@ -121,7 +121,7 @@ fn test_next_fails_on_merge_commit() {
     let repo_path = test_env.env_root().join("repo");
     test_env.jj_cmd_ok(&repo_path, &["branch", "c", "left"]);
     test_env.jj_cmd_ok(&repo_path, &["commit", "-m", "first"]);
-    test_env.jj_cmd_ok(&repo_path, &["co", "@--"]);
+    test_env.jj_cmd_ok(&repo_path, &["new", "@--"]);
     test_env.jj_cmd_ok(&repo_path, &["branch", "c", "right"]);
     test_env.jj_cmd_ok(&repo_path, &["commit", "-m", "second"]);
     test_env.jj_cmd_ok(&repo_path, &["new", "left", "right"]);
@@ -139,9 +139,9 @@ fn test_next_fails_on_branching_children_no_stdin() {
     let repo_path = test_env.env_root().join("repo");
     test_env.jj_cmd_ok(&repo_path, &["commit", "-m", "first"]);
     test_env.jj_cmd_ok(&repo_path, &["commit", "-m", "second"]);
-    test_env.jj_cmd_ok(&repo_path, &["co", "@--"]);
+    test_env.jj_cmd_ok(&repo_path, &["new", "@--"]);
     test_env.jj_cmd_ok(&repo_path, &["commit", "-m", "third"]);
-    test_env.jj_cmd_ok(&repo_path, &["co", "@--"]);
+    test_env.jj_cmd_ok(&repo_path, &["new", "@--"]);
 
     // Try to advance the working copy commit.
     let assert = test_env.jj_cmd(&repo_path, &["next"]).assert().code(1);
@@ -158,9 +158,9 @@ fn test_next_fails_on_branching_children_quit_prompt() {
     let repo_path = test_env.env_root().join("repo");
     test_env.jj_cmd_ok(&repo_path, &["commit", "-m", "first"]);
     test_env.jj_cmd_ok(&repo_path, &["commit", "-m", "second"]);
-    test_env.jj_cmd_ok(&repo_path, &["co", "@--"]);
+    test_env.jj_cmd_ok(&repo_path, &["new", "@--"]);
     test_env.jj_cmd_ok(&repo_path, &["commit", "-m", "third"]);
-    test_env.jj_cmd_ok(&repo_path, &["co", "@--"]);
+    test_env.jj_cmd_ok(&repo_path, &["new", "@--"]);
 
     // Try to advance the working copy commit.
     let assert = test_env
@@ -188,9 +188,9 @@ fn test_next_choose_branching_child() {
     let repo_path = test_env.env_root().join("repo");
     test_env.jj_cmd_ok(&repo_path, &["commit", "-m", "first"]);
     test_env.jj_cmd_ok(&repo_path, &["commit", "-m", "second"]);
-    test_env.jj_cmd_ok(&repo_path, &["co", "@--"]);
+    test_env.jj_cmd_ok(&repo_path, &["new", "@--"]);
     test_env.jj_cmd_ok(&repo_path, &["commit", "-m", "third"]);
-    test_env.jj_cmd_ok(&repo_path, &["co", "@--"]);
+    test_env.jj_cmd_ok(&repo_path, &["new", "@--"]);
     // Advance the working copy commit.
     let (stdout, stderr) = test_env.jj_cmd_stdin_ok(&repo_path, &["next"], "1\n");
     insta::assert_snapshot!(stdout,@r###"
@@ -213,7 +213,7 @@ fn test_prev_fails_on_merge_commit() {
     let repo_path = test_env.env_root().join("repo");
     test_env.jj_cmd_ok(&repo_path, &["branch", "c", "left"]);
     test_env.jj_cmd_ok(&repo_path, &["commit", "-m", "first"]);
-    test_env.jj_cmd_ok(&repo_path, &["co", "@--"]);
+    test_env.jj_cmd_ok(&repo_path, &["new", "@--"]);
     test_env.jj_cmd_ok(&repo_path, &["branch", "c", "right"]);
     test_env.jj_cmd_ok(&repo_path, &["commit", "-m", "second"]);
     test_env.jj_cmd_ok(&repo_path, &["new", "left", "right"]);
@@ -231,7 +231,7 @@ fn test_prev_fails_on_multiple_parents() {
     let repo_path = test_env.env_root().join("repo");
     test_env.jj_cmd_ok(&repo_path, &["branch", "c", "left"]);
     test_env.jj_cmd_ok(&repo_path, &["commit", "-m", "first"]);
-    test_env.jj_cmd_ok(&repo_path, &["co", "@--"]);
+    test_env.jj_cmd_ok(&repo_path, &["new", "@--"]);
     test_env.jj_cmd_ok(&repo_path, &["branch", "c", "right"]);
     test_env.jj_cmd_ok(&repo_path, &["commit", "-m", "second"]);
     // Create a merge commit, which has two parents.

cli/tests/test_squash_command.rs

@@ -104,7 +104,7 @@ fn test_squash() {
     "###);
 
     // Can squash into a merge commit
-    test_env.jj_cmd_ok(&repo_path, &["co", "e"]);
+    test_env.jj_cmd_ok(&repo_path, &["new", "e"]);
     std::fs::write(repo_path.join("file1"), "e\n").unwrap();
     let (stdout, stderr) = test_env.jj_cmd_ok(&repo_path, &["squash"]);
     insta::assert_snapshot!(stdout, @"");

cli/tests/test_unsquash_command.rs

@@ -103,7 +103,7 @@ fn test_unsquash() {
     "###);
 
     // Can unsquash from a merge commit
-    test_env.jj_cmd_ok(&repo_path, &["co", "e"]);
+    test_env.jj_cmd_ok(&repo_path, &["new", "e"]);
     std::fs::write(repo_path.join("file1"), "e\n").unwrap();
     let (stdout, stderr) = test_env.jj_cmd_ok(&repo_path, &["unsquash"]);
     insta::assert_snapshot!(stdout, @"");