Add unittests for changes to fix #4147

* Rename existing test
* Add new tests
* Also update Changelog here

CHANGELOG.md

@@ -101,6 +101,10 @@ to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
 ### Fixed bugs
 
+* `jj status` will show different messages in a conflicted tree, depending
+  on the state of the working commit. In particular, if a child commit has
+  fixed the conflict, this will be reflected in the hint provided by `jj status`
+
 * `jj diff --git` no longer shows the contents of binary files.
 
 * Windows binaries no longer require `vcruntime140.dll` to be installed

cli/tests/test_status_command.rs

@@ -106,7 +106,7 @@ fn test_status_filtered() {
 
 // See <https://github.com/martinvonz/jj/issues/3108>
 #[test]
-fn test_status_display_rebase_instructions() {
+fn test_status_display_rebase_instructions_if_no_decendant_resolves_conflict() {
     let test_env = TestEnvironment::default();
     test_env.jj_cmd_ok(test_env.env_root(), &["git", "init", "repo"]);
 
@@ -177,6 +177,79 @@ fn test_status_display_rebase_instructions() {
     "###);
 }
 
+#[test]
+fn test_status_display_if_child_resolves_conflict() {
+    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:(@-)+"]);
+    // Adding more descendants to ensure we correctly find the root ancestors with
+    // conflicts, not just the parents.
+    test_env.jj_cmd_ok(&repo_path, &["new", "--message", "boom-cont"]);
+    test_env.jj_cmd_ok(&repo_path, &["new", "--message", "boom-cont-2"]);
+    std::fs::write(&conflicted_path, "resolved conflict").unwrap();
+
+    let stdout = test_env.jj_cmd_success(&repo_path, &["log", "-r", "::@"]);
+
+    insta::assert_snapshot!(stdout, @r###"
+    @  yqosqzyt [email protected] 2001-02-03 08:05:13 65143fef conflict
+    │  (empty) boom-cont-2
+    ×  royxmykx [email protected] 2001-02-03 08:05:12 a4e88714 conflict
+    │  (empty) boom-cont
+    ×    mzvwutvl [email protected] 2001-02-03 08:05:11 538415e7 conflict
+    ├─╮  (empty) boom
+    │ ○  kkmpptxz [email protected] 2001-02-03 08:05:10 1e8c2956
+    │ │  First part of conflicting change
+    ○ │  zsuskuln [email protected] 2001-02-03 08:05:11 2c8b19fd
+    ├─╯  Second part of conflicting change
+    ○  qpvuntsm [email protected] 2001-02-03 08:05:08 aade7195
+    │  Initial contents
+    ◆  zzzzzzzz root() 00000000
+    "###);
+
+    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
+    Working copy : yqosqzyt 65143fef (conflict) (empty) boom-cont-2
+    Parent commit: royxmykx a4e88714 (conflict) (empty) boom-cont
+    To resolve the conflicts, start by updating to the first one:
+      jj new mzvwutvlkqwt
+    Then use `jj resolve`, or edit the conflict markers in the file directly.
+    Once the conflicts are resolved, you may want to inspect the result with `jj diff`.
+    Then run `jj squash` to move the resolution into the conflicted commit.
+    "###);
+}
+
 #[test]
 fn test_status_simplify_conflict_sides() {
     let test_env = TestEnvironment::default();