copy-tracking: implement copy tracking for external tools

CHANGELOG.md

@@ -15,7 +15,8 @@ to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 ### New features
 
 * The following diff formats now include information about copies and moves:
-  `--color-words`, `--git`, `--stat`, `--summary`, `--types`
+  `--color-words`, `--git`, `--stat`, `--summary`, `--types`, and external diff
+  tools in file-by-file mode.
 
 * A tilde (`~`) at the start of the path will now be expanded to the user's home
   directory when configuring a `signing.key` for SSH commit signing.

cli/src/diff_util.rs

@@ -324,15 +324,15 @@ impl<'a> DiffRenderer<'a> {
                 DiffFormat::Tool(tool) => {
                     match tool.diff_invocation_mode {
                         DiffToolMode::FileByFile => {
-                            let no_copy_tracking = Default::default();
-                            let tree_diff =
-                                from_tree.diff_stream(to_tree, matcher, &no_copy_tracking);
+                            let tree_diff = from_tree.diff_stream(to_tree, matcher, copy_records);
                             show_file_by_file_diff(
                                 ui,
                                 formatter,
                                 store,
                                 tree_diff,
                                 path_converter,
+                                matcher,
+                                copy_records,
                                 tool,
                             )
                         }
@@ -753,12 +753,15 @@ pub fn show_color_words_diff(
     .block_on()
 }
 
+#[allow(clippy::too_many_arguments)]
 pub fn show_file_by_file_diff(
     ui: &Ui,
     formatter: &mut dyn Formatter,
     store: &Store,
     tree_diff: TreeDiffStream,
     path_converter: &RepoPathUiConverter,
+    matcher: &dyn Matcher,
+    copy_records: &CopyRecords,
     tool: &ExternalMergeTool,
 ) -> Result<(), DiffRenderError> {
     fn create_file(
@@ -772,35 +775,48 @@ pub fn show_file_by_file_diff(
         std::fs::write(&fs_path, content.contents)?;
         Ok(fs_path)
     }
+    let copied_sources = collect_copied_sources(copy_records, matcher);
 
     let temp_dir = new_utf8_temp_dir("jj-diff-")?;
     let left_wc_dir = temp_dir.path().join("left");
     let right_wc_dir = temp_dir.path().join("right");
     let mut diff_stream = materialized_diff_stream(store, tree_diff);
     async {
         while let Some(MaterializedTreeDiffEntry {
-            source: _, // TODO handle copy tracking
-            target: path,
+            source: left_path,
+            target: right_path,
             value: diff,
         }) = diff_stream.next().await
         {
-            let ui_path = path_converter.format_file_path(&path);
             let (left_value, right_value) = diff?;
+            if right_value.is_absent() && copied_sources.contains(left_path.as_ref()) {
+                continue;
+            }
+
+            let left_ui_path = path_converter.format_file_path(&left_path);
+            let right_ui_path = path_converter.format_file_path(&right_path);
 
             match (&left_value, &right_value) {
-                (_, MaterializedTreeValue::AccessDenied(source))
-                | (MaterializedTreeValue::AccessDenied(source), _) => {
+                (_, MaterializedTreeValue::AccessDenied(source)) => {
+                    write!(
+                        formatter.labeled("access-denied"),
+                        "Access denied to {right_ui_path}:"
+                    )?;
+                    writeln!(formatter, " {source}")?;
+                    continue;
+                }
+                (MaterializedTreeValue::AccessDenied(source), _) => {
                     write!(
                         formatter.labeled("access-denied"),
-                        "Access denied to {ui_path}:"
+                        "Access denied to {left_ui_path}:"
                     )?;
                     writeln!(formatter, " {source}")?;
                     continue;
                 }
                 _ => {}
             }
-            let left_path = create_file(&path, &left_wc_dir, left_value)?;
-            let right_path = create_file(&path, &right_wc_dir, right_value)?;
+            let left_path = create_file(&left_path, &left_wc_dir, left_value)?;
+            let right_path = create_file(&right_path, &right_wc_dir, right_value)?;
 
             invoke_external_diff(
                 ui,

cli/tests/test_diff_command.rs

@@ -1253,6 +1253,7 @@ fn test_diff_external_file_by_file_tool() {
     std::fs::remove_file(repo_path.join("file1")).unwrap();
     std::fs::write(repo_path.join("file2"), "file2\nfile2\n").unwrap();
     std::fs::write(repo_path.join("file3"), "file3\n").unwrap();
+    std::fs::write(repo_path.join("file4"), "file1\n").unwrap();
 
     let edit_script = test_env.set_up_fake_diff_editor();
     std::fs::write(
@@ -1269,17 +1270,17 @@ fn test_diff_external_file_by_file_tool() {
     insta::assert_snapshot!(
         test_env.jj_cmd_success(&repo_path, &["diff", config]), @r###"
     ==
-    file1
-    --
-    file1
-    ==
     file2
     --
     file2
     ==
     file3
     --
     file3
+    ==
+    file1
+    --
+    file4
     "###);
 
     // diff with file patterns
@@ -1293,20 +1294,20 @@ fn test_diff_external_file_by_file_tool() {
 
     insta::assert_snapshot!(
         test_env.jj_cmd_success(&repo_path, &["log", "-p", config]), @r###"
-    @  rlvkpnrz [email protected] 2001-02-03 08:05:09 f12f62fb
+    @  rlvkpnrz [email protected] 2001-02-03 08:05:09 7b01704a
     │  (no description set)
     │  ==
-    │  file1
-    │  --
-    │  file1
-    │  ==
     │  file2
     │  --
     │  file2
     │  ==
     │  file3
     │  --
     │  file3
+    │  ==
+    │  file1
+    │  --
+    │  file4
     ○  qpvuntsm [email protected] 2001-02-03 08:05:08 6e485984
     │  (no description set)
     │  ==
@@ -1322,17 +1323,13 @@ fn test_diff_external_file_by_file_tool() {
 
     insta::assert_snapshot!(
         test_env.jj_cmd_success(&repo_path, &["show", config]), @r###"
-    Commit ID: f12f62fb1d73629c1b44abd4d5bbb500d7f8b86c
+    Commit ID: 7b01704a670bc77d11ed117d362855cff1d4513b
     Change ID: rlvkpnrzqnoowoytxnquwvuryrwnrmlp
     Author: Test User <[email protected]> (2001-02-03 08:05:09)
     Committer: Test User <[email protected]> (2001-02-03 08:05:09)
 
         (no description set)
 
-    ==
-    file1
-    --
-    file1
     ==
     file2
     --
@@ -1341,6 +1338,10 @@ fn test_diff_external_file_by_file_tool() {
     file3
     --
     file3
+    ==
+    file1
+    --
+    file4
     "###);
 }