next/prev: Add config flag to control prev/next edit behaviour.

The flag is a tristate flag where:
  - Auto - Maintain current behaviour. This edits if
    the wc parent is not a head commit. Else, it will
    create a new commit on the parent of the wc in
    the direction of movement.
  - Always - Always edit
  - Never - Never edit, prefer the new+squash workflow.

Also add a `--no-edit` flag as the explicit inverse of `--edit` and
ensure both flags take precedence over the config.

Part of #3947

CHANGELOG.md

@@ -70,6 +70,10 @@ to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
 ### New features
 
+* Add new config knob, `ui.movement.edit` for controlling the behaviour of `prev/next`.
+  `auto` maintains existing behaviour while `always` and `never` turn `edit` mode
+  permanently `on` and `off` respectively.
+
 * Define `immutable_heads()` revset alias in terms of a new `builtin_immutable_heads()`.
   This enables users to redefine `immutable_heads()` as they wish, but still
   have `builtin_immutable_heads()` which should not be redefined.

cli/src/commands/next.rs

@@ -56,9 +56,15 @@ pub(crate) struct NextArgs {
     offset: u64,
     /// Instead of creating a new working-copy commit on top of the target
     /// commit (like `jj new`), edit the target commit directly (like `jj
-    /// edit`).
-    #[arg(long, short)]
+    /// edit`). Takes precedence over config in `ui.movement.edit`; i.e.
+    /// will negate `ui.movement.edit = "never"`
+    #[arg(long, short, conflicts_with = "no_edit")]
     edit: bool,
+    /// The inverse of `--edit`.
+    /// Takes precedence over config in `ui.movement.edit`; i.e.
+    /// will negate `ui.movement.edit = "always"`
+    #[arg(long, short, conflicts_with = "edit")]
+    no_edit: bool,
     /// Jump to the next conflicted descendant.
     #[arg(long, conflicts_with = "offset")]
     conflict: bool,
@@ -69,6 +75,7 @@ impl Into<MovementArgs> for &NextArgs {
         MovementArgs {
             offset: self.offset,
             edit: self.edit,
+            no_edit: self.no_edit,
             conflict: self.conflict,
         }
     }
@@ -80,5 +87,5 @@ pub(crate) fn cmd_next(
     args: &NextArgs,
 ) -> Result<(), CommandError> {
     let mut workspace_command = command.workspace_helper(ui)?;
-    move_to_commit(ui, &mut workspace_command, &Direction::Next, &args.into())
+    move_to_commit(ui, command, &Direction::Next, &args.into())
 }

cli/src/commands/prev.rs

@@ -53,8 +53,15 @@ pub(crate) struct PrevArgs {
     #[arg(default_value = "1")]
     offset: u64,
     /// Edit the parent directly, instead of moving the working-copy commit.
+    /// Takes precedence over config in `ui.movement.edit`; i.e.
+    /// will negate `ui.movement.edit = "never"`
     #[arg(long, short)]
     edit: bool,
+    /// The inverse of `--edit`.
+    /// Takes precedence over config in `ui.movement.edit`; i.e.
+    /// will negate `ui.movement.edit = "always"`
+    #[arg(long, short, conflicts_with = "edit")]
+    no_edit: bool,
     /// Jump to the previous conflicted ancestor.
     #[arg(long, conflicts_with = "offset")]
     conflict: bool,
@@ -65,6 +72,7 @@ impl Into<MovementArgs> for &PrevArgs {
         MovementArgs {
             offset: self.offset,
             edit: self.edit,
+            no_edit: self.no_edit,
             conflict: self.conflict,
         }
     }
@@ -75,6 +83,5 @@ pub(crate) fn cmd_prev(
     command: &CommandHelper,
     args: &PrevArgs,
 ) -> Result<(), CommandError> {
-    let mut workspace_command = command.workspace_helper(ui)?;
-    move_to_commit(ui, &mut workspace_command, &Direction::Prev, &args.into())
+    move_to_commit(ui, command, &Direction::Prev, &args.into())
 }

cli/src/config/misc.toml

@@ -18,5 +18,8 @@ pager = { command = ["less", "-FRX"], env = { LESSCHARSET = "utf-8" } }
 log-word-wrap = false
 log-synthetic-elided-nodes = true
 
+[ui.movement]
+edit = "auto"
+
 [snapshot]
 max-new-file-size = "1MiB"

cli/src/movement_util.rs

@@ -15,14 +15,15 @@
 use std::io::Write;
 use std::rc::Rc;
 
+use config::Config;
 use itertools::Itertools;
 use jj_lib::backend::CommitId;
 use jj_lib::commit::Commit;
 use jj_lib::repo::Repo;
 use jj_lib::revset::{RevsetExpression, RevsetFilterPredicate, RevsetIteratorExt};
 
-use crate::cli_util::{short_commit_hash, WorkspaceCommandHelper};
-use crate::command_error::{user_error, CommandError};
+use crate::cli_util::{short_commit_hash, WorkspaceCommandHelper, CommandHelper};
+use crate::command_error::{config_error_with_message, user_error, CommandError};
 use crate::ui::Ui;
 
 #[derive(Clone, Copy, Debug, Eq, PartialEq)]
@@ -162,25 +163,35 @@ fn choose_commit<'a>(
 
 pub(crate) fn move_to_commit(
     ui: &mut Ui,
-    workspace_command: &mut WorkspaceCommandHelper,
+    command: &CommandHelper,
+    config: &config::Config,
     direction: &Direction,
     args: &MovementArgs,
 ) -> Result<(), CommandError> {
+    let mut workspace_command = command.workspace_helper(ui)?;
+
     let current_wc_id = workspace_command
         .get_wc_commit_id()
         .ok_or_else(|| user_error("This command requires a working copy"))?;
     let edit = args.edit
-        || !&workspace_command
+         || !&workspace_command
+    let config_edit_flag = match MovementSettings::try_from(command.settings().config())?.edit_mode() {
+        MovementEditMode::Always => true,
+        MovementEditMode::Never => false,
+        MovementEditMode::Auto => !&workspace_command
             .repo()
             .view()
             .heads()
-            .contains(current_wc_id);
+            .contains(current_wc_id),
+    };
+
+    let edit = edit || (!no_edit && config_edit_flag);
+
     let target = get_target_commit(ui, workspace_command, direction, current_wc_id, args)?;
 
     let current_short = short_commit_hash(current_wc_id);
     let target_short = short_commit_hash(target.id());
     let cmd = direction.cmd();
-
     // We're editing, just move to the target commit.
     if edit {
         // We're editing, the target must be rewritable.
@@ -199,3 +210,34 @@ pub(crate) fn move_to_commit(
     tx.finish(ui, format!("{cmd}: {current_short} -> {target_short}"))?;
     Ok(())
 }
+
+#[derive(Clone, Copy, Debug, Default, Eq, PartialEq, serde::Deserialize)]
+#[serde(rename_all(deserialize = "kebab-case"))]
+pub enum MovementEditMode {
+    #[default]
+    Auto,
+    Always,
+    Never,
+}
+
+#[derive(Clone, Copy, Debug, Default, Eq, PartialEq, serde::Deserialize)]
+#[serde(rename_all(deserialize = "kebab-case"))]
+pub struct MovementSettings {
+    edit: MovementEditMode,
+}
+
+impl MovementSettings {
+    fn edit_mode(&self) -> MovementEditMode {
+        self.edit
+    }
+}
+
+impl TryFrom<&Config> for MovementSettings {
+    type Error = CommandError;
+
+    fn try_from(config: &Config) -> Result<Self, CommandError> {
+        config
+            .get::<Self>("ui.movement")
+            .map_err(|err| config_error_with_message("Invalid `ui.movement`", err))
+    }
+}

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

@@ -1225,7 +1225,8 @@ implied.
 
 ###### **Options:**
 
-* `-e`, `--edit` — Instead of creating a new working-copy commit on top of the target commit (like `jj new`), edit the target commit directly (like `jj edit`)
+* `-e`, `--edit` — Instead of creating a new working-copy commit on top of the target commit (like `jj new`), edit the target commit directly (like `jj edit`). Takes precedence over config in `ui.movement.edit`; i.e. will negate `ui.movement.edit = "never"`
+* `-n`, `--no-edit` — The inverse of `--edit`. Takes precedence over config in `ui.movement.edit`; i.e. will negate `ui.movement.edit = "always"`
 * `--conflict` — Jump to the next conflicted descendant
 
 
@@ -1529,7 +1530,8 @@ implied.
 
 ###### **Options:**
 
-* `-e`, `--edit` — Edit the parent directly, instead of moving the working-copy commit
+* `-e`, `--edit` — Edit the parent directly, instead of moving the working-copy commit. Takes precedence over config in `ui.movement.edit`; i.e. will negate `ui.movement.edit = "never"`
+* `-n`, `--no-edit` — The inverse of `--edit`. Takes precedence over config in `ui.movement.edit`; i.e. will negate `ui.movement.edit = "always"`
 * `--conflict` — Jump to the previous conflicted ancestor