cli: status: when current change has conflicts, display instructions …

…to resolve them

cli/src/cli_util.rs

@@ -1254,38 +1254,60 @@ See https://github.com/martinvonz/jj/blob/main/docs/working-copy.md#stale-workin
                 .iter()
                 .commits(new_repo.store())
                 .try_collect()?;
-            if !root_conflict_commits.is_empty() {
-                fmt.push_label("hint")?;
-                if added_conflict_commits.len() == 1 {
-                    writeln!(fmt, "To resolve the conflicts, start by updating to it:",)?;
-                } else if root_conflict_commits.len() == 1 {
-                    writeln!(
-                        fmt,
-                        "To resolve the conflicts, start by updating to the first one:",
-                    )?;
-                } else {
-                    writeln!(
-                        fmt,
-                        "To resolve the conflicts, start by updating to one of the first ones:",
-                    )?;
-                }
-                for commit in root_conflict_commits {
-                    writeln!(fmt, "  jj new {}", short_change_hash(commit.change_id()))?;
-                }
-                writeln!(
-                    fmt,
-                    r#"Then use `jj resolve`, or edit the conflict markers in the file directly.
-Once the conflicts are resolved, you may want inspect the result with `jj diff`.
-Then run `jj squash` to move the resolution into the conflicted commit."#,
-                )?;
-                fmt.pop_label()?;
-            }
+
+            let hint_start = if added_conflict_commits.len() == 1 {
+                "To resolve the conflicts, start by updating to it:"
+            } else if root_conflict_commits.len() == 1 {
+                "To resolve the conflicts, start by updating to the first one:"
+            } else {
+                "To resolve the conflicts, start by updating to one of the first ones:"
+            };
+            print_conflict_resolution_hint(fmt.as_mut(), hint_start, &root_conflict_commits)?;
         }
 
         Ok(())
     }
 }
 
+/// Prints conflict resolution hints when apprioriate.
+///
+/// `hint_start` is used to adapt the hint to the situation (for example, adapt
+/// the hint to conflicts introduced after a rebase or to being in the middle of
+/// a rebase where the focus will be the current change).
+pub(crate) fn print_conflict_resolution_hint<C>(
+    fmt: &mut (dyn Formatter + '_),
+    hint_start: &str,
+    conflict_commits: &[C],
+) -> Result<(), CommandError>
+where
+    C: AsRef<Commit>,
+{
+    if conflict_commits.is_empty() {
+        return Ok(());
+    }
+
+    fmt.push_label("hint")?;
+    writeln!(fmt, "{hint_start}")?;
+
+    for commit in conflict_commits {
+        writeln!(
+            fmt,
+            "  jj new {}",
+            short_change_hash(commit.as_ref().change_id())
+        )?;
+    }
+
+    writeln!(
+        fmt,
+        r#"Then use `jj resolve`, or edit the conflict markers in the file directly.
+Once the conflicts are resolved, you may want inspect the result with `jj diff`.
+Then run `jj squash` to move the resolution into the conflicted commit."#,
+    )?;
+
+    fmt.pop_label()?;
+    Ok(())
+}
+
 #[must_use]
 pub struct WorkspaceCommandTransaction<'a> {
     helper: &'a mut WorkspaceCommandHelper,

cli/src/commands/status.rs

@@ -72,7 +72,13 @@ pub(crate) fn cmd_status(
                 formatter.labeled("conflict"),
                 "There are unresolved conflicts at these paths:"
             )?;
-            resolve::print_conflicted_paths(&conflicts, formatter, &workspace_command)?
+            resolve::print_conflicted_paths(&conflicts, formatter, &workspace_command)?;
+
+            crate::cli_util::print_conflict_resolution_hint(
+                formatter,
+                "To resolve the conflicts, start by updating the current change:",
+                &[wc_commit],
+            )?;
         }
 
         formatter.write_str("Working copy : ")?;

cli/tests/test_status_command.rs

@@ -62,3 +62,54 @@ fn test_status_ignored_gitignore() {
     Parent commit: zzzzzzzz 00000000 (empty) (no description set)
     "###);
 }
+
+// See <https://github.com/martinvonz/jj/issues/3108>
+#[test]
+fn test_status_display_rebase_instructions() {
+    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");
+    let conflicted_path = repo_path.join("conflicted.txt");
+
+    // PARENT: Write the initial file
+    std::fs::write(&conflicted_path, "initial contents").unwrap();
+    test_env.jj_cmd_ok(&repo_path, &["describe", "--message", "Initial contents"]);
+
+    // CHILD1: New commit on top of <PARENT>
+    test_env.jj_cmd_ok(
+        &repo_path,
+        &["new", "--message", "First part of conflicting change"],
+    );
+    std::fs::write(&conflicted_path, "Child 1").unwrap();
+
+    // CHILD2: New commit also on top of <PARENT>
+    test_env.jj_cmd_ok(
+        &repo_path,
+        &[
+            "new",
+            "--message",
+            "Second part of conflicting change",
+            "@-",
+        ],
+    );
+    std::fs::write(&conflicted_path, "Child 2").unwrap();
+
+    // CONFLICT: New commit that is conflicted by merging <CHILD1> and <CHILD2>
+    test_env.jj_cmd_ok(&repo_path, &["new", "--message", "boom", "all:(@-)+"]);
+    let stdout = test_env.jj_cmd_success(&repo_path, &["status"]);
+
+    insta::assert_snapshot!(stdout, @r###"
+    The working copy is clean
+    There are unresolved conflicts at these paths:
+    conflicted.txt    2-sided conflict
+    To resolve the conflicts, start by updating the current change:
+      jj new mzvwutvlkqwt
+    Then use `jj resolve`, or edit the conflict markers in the file directly.
+    Once the conflicts are resolved, you may want inspect the result with `jj diff`.
+    Then run `jj squash` to move the resolution into the conflicted commit.
+    Working copy : mzvwutvl 5c0db5c6 (conflict) (empty) boom
+    Parent commit: zsuskuln ba5f8773 Second part of conflicting change
+    Parent commit: kkmpptxz 55ce6709 First part of conflicting change
+    "###);
+}

lib/src/commit.rs

@@ -64,6 +64,12 @@ impl Hash for Commit {
     }
 }
 
+impl AsRef<Self> for Commit {
+    fn as_ref(&self) -> &Self {
+        self
+    }
+}
+
 impl Commit {
     pub fn new(store: Arc<Store>, id: CommitId, data: Arc<backend::Commit>) -> Self {
         Commit { store, id, data }