cli: op log: add --reversed option

Closes #4190.

CHANGELOG.md

@@ -55,7 +55,7 @@ to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
 ### New features
 
-* `jj evolog` now accepts `--reversed`.
+* `jj evolog` and `jj op log` now accept `--reversed`.
 
 * `jj restore` now supports `-i`/`--interactive` selection.
 

cli/src/commands/operation/log.rs

@@ -17,7 +17,9 @@ use std::slice;
 use itertools::Itertools as _;
 use jj_lib::config::ConfigGetError;
 use jj_lib::config::ConfigGetResultExt as _;
+use jj_lib::graph::reverse_graph;
 use jj_lib::graph::GraphEdge;
+use jj_lib::op_store::OpStoreError;
 use jj_lib::op_walk;
 use jj_lib::operation::Operation;
 use jj_lib::repo::RepoLoader;
@@ -47,8 +49,13 @@ use crate::ui::Ui;
 #[derive(clap::Args, Clone, Debug)]
 pub struct OperationLogArgs {
     /// Limit number of operations to show
+    ///
+    /// Applied after operations are reordered.
     #[arg(long, short = 'n')]
     limit: Option<usize>,
+    /// Show operations in the opposite order (older operations first)
+    #[arg(long)]
+    reversed: bool,
     /// Don't show the graph, show a flat list of operations
     #[arg(long)]
     no_graph: bool,
@@ -190,16 +197,27 @@ fn do_op_log(
     let mut formatter = ui.stdout_formatter();
     let formatter = formatter.as_mut();
     let limit = args.limit.unwrap_or(usize::MAX);
-    let iter = op_walk::walk_ancestors(slice::from_ref(current_op)).take(limit);
+    let iter = op_walk::walk_ancestors(slice::from_ref(current_op));
+
     if !args.no_graph {
         let mut raw_output = formatter.raw()?;
         let mut graph = get_graphlog(graph_style, raw_output.as_mut());
-        for op in iter {
+        let iter = iter.map(|op| -> Result<_, OpStoreError> {
             let op = op?;
-            let mut edges = vec![];
-            for id in op.parent_ids() {
-                edges.push(GraphEdge::direct(id.clone()));
-            }
+            let edges = op.parents().map_ok(GraphEdge::direct).try_collect()?;
+            Ok((op, edges))
+        });
+        let iter_nodes: Box<dyn Iterator<Item = _>> = if args.reversed {
+            Box::new(reverse_graph(iter)?.into_iter().map(Ok))
+        } else {
+            Box::new(iter)
+        };
+        for node in iter_nodes.take(limit) {
+            let (op, edges) = node?;
+            let edges = edges
+                .into_iter()
+                .map(|e| e.map(|e| e.id().clone()))
+                .collect_vec();
             let mut buffer = vec![];
             let within_graph = with_content_format.sub_width(graph.width(op.id(), &edges));
             within_graph.write(ui.new_formatter(&mut buffer).as_mut(), |formatter| {
@@ -221,7 +239,12 @@ fn do_op_log(
             )?;
         }
     } else {
-        for op in iter {
+        let iter: Box<dyn Iterator<Item = _>> = if args.reversed {
+            Box::new(iter.collect_vec().into_iter().rev())
+        } else {
+            Box::new(iter)
+        };
+        for op in iter.take(limit) {
             let op = op?;
             with_content_format.write(formatter, |formatter| template.format(&op, formatter))?;
             if let Some(show) = &maybe_show_op_diff {

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

@@ -1544,6 +1544,9 @@ Like other commands, `jj op log` snapshots the current working-copy changes and
 ###### **Options:**
 
 * `-n`, `--limit <LIMIT>` — Limit number of operations to show
+
+   Applied after operations are reordered.
+* `--reversed` — Show operations in the opposite order (older operations first)
 * `--no-graph` — Don't show the graph, show a flat list of operations
 * `-T`, `--template <TEMPLATE>` — Render each operation using the given template
 

cli/tests/test_operations.rs

@@ -192,6 +192,72 @@ fn test_op_log_no_graph() {
     "#);
 }
 
+#[test]
+fn test_op_log_reversed() {
+    let test_env = TestEnvironment::default();
+    test_env.jj_cmd_ok(test_env.env_root(), &["git", "init", "repo"]);
+    let repo_path = test_env.env_root().join("repo");
+    test_env.jj_cmd_ok(&repo_path, &["describe", "-m", "description 0"]);
+
+    let stdout = test_env.jj_cmd_success(&repo_path, &["op", "log", "--reversed"]);
+    insta::assert_snapshot!(&stdout, @r#"
+    ○  000000000000 root()
+    ○  eac759b9ab75 [email protected] 2001-02-03 04:05:07.000 +07:00 - 2001-02-03 04:05:07.000 +07:00
+    │  add workspace 'default'
+    @  d009cfc04993 [email protected] 2001-02-03 04:05:08.000 +07:00 - 2001-02-03 04:05:08.000 +07:00
+       describe commit 230dd059e1b059aefc0da06a2e5a7dbf22362f22
+       args: jj describe -m 'description 0'
+    "#);
+
+    test_env.jj_cmd_ok(
+        &repo_path,
+        &["describe", "-m", "description 1", "--at-op", "@-"],
+    );
+
+    // Should be able to display log with fork and branch points
+    let (stdout, stderr) = test_env.jj_cmd_ok(&repo_path, &["op", "log", "--reversed"]);
+    insta::assert_snapshot!(&stderr, @"Concurrent modification detected, resolving automatically.");
+    insta::assert_snapshot!(&stdout, @r#"
+    ○  000000000000 root()
+    ○    eac759b9ab75 [email protected] 2001-02-03 04:05:07.000 +07:00 - 2001-02-03 04:05:07.000 +07:00
+    ├─╮  add workspace 'default'
+    │ ○  8e3e726be123 [email protected] 2001-02-03 04:05:10.000 +07:00 - 2001-02-03 04:05:10.000 +07:00
+    │ │  describe commit 230dd059e1b059aefc0da06a2e5a7dbf22362f22
+    │ │  args: jj describe -m 'description 1' --at-op @-
+    ○ │  d009cfc04993 [email protected] 2001-02-03 04:05:08.000 +07:00 - 2001-02-03 04:05:08.000 +07:00
+    ├─╯  describe commit 230dd059e1b059aefc0da06a2e5a7dbf22362f22
+    │    args: jj describe -m 'description 0'
+    @  e4538ffdc13d [email protected] 2001-02-03 04:05:11.000 +07:00 - 2001-02-03 04:05:11.000 +07:00
+       reconcile divergent operations
+       args: jj op log --reversed
+    "#);
+
+    // Should work correctly with `--no-graph`
+    let stdout = test_env.jj_cmd_success(&repo_path, &["op", "log", "--reversed", "--no-graph"]);
+    insta::assert_snapshot!(&stdout, @r#"
+    000000000000 root()
+    eac759b9ab75 [email protected] 2001-02-03 04:05:07.000 +07:00 - 2001-02-03 04:05:07.000 +07:00
+    add workspace 'default'
+    8e3e726be123 [email protected] 2001-02-03 04:05:10.000 +07:00 - 2001-02-03 04:05:10.000 +07:00
+    describe commit 230dd059e1b059aefc0da06a2e5a7dbf22362f22
+    args: jj describe -m 'description 1' --at-op @-
+    d009cfc04993 [email protected] 2001-02-03 04:05:08.000 +07:00 - 2001-02-03 04:05:08.000 +07:00
+    describe commit 230dd059e1b059aefc0da06a2e5a7dbf22362f22
+    args: jj describe -m 'description 0'
+    e4538ffdc13d [email protected] 2001-02-03 04:05:11.000 +07:00 - 2001-02-03 04:05:11.000 +07:00
+    reconcile divergent operations
+    args: jj op log --reversed
+    "#);
+
+    // Should work correctly with `--limit`
+    let stdout = test_env.jj_cmd_success(&repo_path, &["op", "log", "--reversed", "--limit=2"]);
+    insta::assert_snapshot!(stdout, @r#"
+    ○  000000000000 root()
+    ○    eac759b9ab75 [email protected] 2001-02-03 04:05:07.000 +07:00 - 2001-02-03 04:05:07.000 +07:00
+    ├─╮  add workspace 'default'
+    "#);
+}
+
 #[test]
 fn test_op_log_no_graph_null_terminated() {
     let test_env = TestEnvironment::default();