copy-tracking: add support for copies tracking to diff --stat

CHANGELOG.md

@@ -15,7 +15,7 @@ to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 ### New features
 
 * `jj diff` the following subcommands now include information about copies and
-  moves if supported by the backend: `jj diff --summary`
+  moves if supported by the backend: `jj diff --summary`, `jj diff --stat`
 
 ### Fixed bugs
 

cli/Cargo.toml

@@ -93,6 +93,7 @@ toml_edit = { workspace = true }
 tracing = { workspace = true }
 tracing-chrome = { workspace = true }
 tracing-subscriber = { workspace = true }
+unicode-segmentation = "1.11.0"
 unicode-width = { workspace = true }
 
 [target.'cfg(unix)'.dependencies]

cli/src/diff_util.rs

@@ -13,7 +13,7 @@
 // limitations under the License.
 
 use std::cmp::max;
-use std::collections::{HashMap, VecDeque};
+use std::collections::{HashMap, HashSet, VecDeque};
 use std::ops::Range;
 use std::path::{Path, PathBuf};
 use std::{io, mem};
@@ -284,8 +284,7 @@ impl<'a> DiffRenderer<'a> {
                     show_diff_summary(formatter, tree_diff, path_converter)?;
                 }
                 DiffFormat::Stat => {
-                    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_diff_stat(formatter, store, tree_diff, path_converter, width)?;
                 }
                 DiffFormat::Types => {
@@ -1226,6 +1225,7 @@ struct DiffStat {
     path: String,
     added: usize,
     removed: usize,
+    is_deletion: bool,
 }
 
 fn get_diff_stat(
@@ -1253,6 +1253,7 @@ fn get_diff_stat(
         path,
         added,
         removed,
+        is_deletion: right_content.contents.is_empty(),
     }
 }
 
@@ -1264,21 +1265,28 @@ pub fn show_diff_stat(
     display_width: usize,
 ) -> Result<(), DiffRenderError> {
     let mut stats: Vec<DiffStat> = vec![];
+    let mut unresolved_renames = HashSet::<String>::new();
     let mut max_path_width = 0;
     let mut max_diffs = 0;
 
     let mut diff_stream = materialized_diff_stream(store, tree_diff);
     async {
         while let Some(MaterializedTreeDiffEntry {
-            source: _,
-            target: repo_path,
+            source: left_path,
+            target: right_path,
             value: diff,
         }) = diff_stream.next().await
         {
             let (left, right) = diff?;
-            let path = path_converter.format_file_path(&repo_path);
-            let left_content = diff_content(&repo_path, left)?;
-            let right_content = diff_content(&repo_path, right)?;
+            let left_content = diff_content(&left_path, left)?;
+            let right_content = diff_content(&right_path, right)?;
+
+            let left_ui_path = path_converter.format_file_path(&left_path);
+            let right_ui_path = path_converter.format_file_path(&right_path);
+            if left_ui_path != right_ui_path {
+                unresolved_renames.insert(left_ui_path.clone());
+            }
+            let path = text_util::render_copied_path(&left_ui_path, &right_ui_path);
             max_path_width = max(max_path_width, path.width());
             let stat = get_diff_stat(path, &left_content, &right_content);
             max_diffs = max(max_diffs, stat.added + stat.removed);
@@ -1303,10 +1311,15 @@ pub fn show_diff_stat(
 
     let mut total_added = 0;
     let mut total_removed = 0;
-    let total_files = stats.len();
+    let mut total_files = 0;
     for stat in &stats {
+        if stat.is_deletion && unresolved_renames.contains(&stat.path) {
+            continue;
+        }
+
         total_added += stat.added;
         total_removed += stat.removed;
+        total_files += 1;
         let bar_added = (stat.added as f64 * factor).ceil() as usize;
         let bar_removed = (stat.removed as f64 * factor).ceil() as usize;
         // replace start of path with ellipsis if the path is too long

cli/src/text_util.rs

@@ -15,6 +15,9 @@
 use std::borrow::Cow;
 use std::{cmp, io};
 
+use itertools::Itertools;
+
+use unicode_segmentation::UnicodeSegmentation;
 use unicode_width::UnicodeWidthChar as _;
 
 use crate::formatter::{FormatRecorder, Formatter};
@@ -35,6 +38,33 @@ pub fn split_email(email: &str) -> (&str, Option<&str>) {
     }
 }
 
+pub fn render_copied_path(source: &str, target: &str) -> String {
+    if source == target {
+        return target.into();
+    }
+    let prefix = UnicodeSegmentation::split_word_bound_indices(source)
+        .zip(UnicodeSegmentation::split_word_bound_indices(target))
+        .take_while_inclusive(|((_, s), (_, t))| s == t)
+        .last()
+        .map(|((s, _), (t, _))| (s, t))
+        .unwrap_or((0, 0));
+    let suffix = UnicodeSegmentation::split_word_bound_indices(source)
+        .rev()
+        .zip(UnicodeSegmentation::split_word_bound_indices(target).rev())
+        .take_while(|((_, s), (_, t))| s == t)
+        .last()
+        .map(|((s, _), (t, _))| (s, t))
+        .unwrap_or((source.len(), target.len()));
+
+    format!(
+        "{}{{{} => {}}}{}",
+        &source[0..prefix.0],
+        &source[prefix.0..suffix.0.max(prefix.0)],
+        &target[prefix.1..suffix.1.max(prefix.1)],
+        &source[suffix.0..]
+    )
+}
+
 /// Shortens `text` to `max_width` by removing leading characters. `ellipsis` is
 /// added if the `text` gets truncated.
 ///
@@ -629,4 +659,30 @@ mod tests {
             "foo\n",
         );
     }
+
+    #[test]
+    fn test_render_copied_path() {
+        assert_eq!(
+            render_copied_path("one/two/three", "one/two/three"),
+            "one/two/three"
+        );
+        assert_eq!(
+            render_copied_path("two/three", "four/three"),
+            "{two => four}/three"
+        );
+        assert_eq!(
+            render_copied_path("one/two/three", "one/four/three"),
+            "one/{two => four}/three"
+        );
+        assert_eq!(
+            render_copied_path("one/two/three", "one/three"),
+            "one/{two => }/three"
+        );
+        assert_eq!(
+            render_copied_path("one/two", "one/four"),
+            "one/{two => four}"
+        );
+        assert_eq!(render_copied_path("two", "four"), "{two => four}");
+        assert_eq!(render_copied_path("file1", "file2"), "{file1 => file2}");
+    }
 }

cli/tests/test_diff_command.rs

@@ -189,10 +189,9 @@ fn test_diff_basic() {
 
     let stdout = test_env.jj_cmd_success(&repo_path, &["diff", "--stat"]);
     insta::assert_snapshot!(stdout, @r###"
-    file1 | 1 -
-    file2 | 3 ++-
-    file3 | 1 +
-    3 files changed, 3 insertions(+), 2 deletions(-)
+    file2            | 3 ++-
+    {file1 => file3} | 0
+    2 files changed, 2 insertions(+), 1 deletion(-)
     "###);
 
     // Filter by glob pattern