improve: show whole-diff totals alongside file stats

tests/repository.rs

@@ -275,6 +275,93 @@ fn comparison_revisions_freeze_commits_and_address_working_contents() {
     }
 }
 
+#[test]
+fn unopened_catalog_counts_frozen_text_but_not_binary_modes_or_exact_renames() {
+    let fixture = Fixture::new();
+    let root = fixture.dir("stats");
+    init_git(&root);
+    for (path, bytes) in [
+        ("first", &b"old\nkeep\n"[..]),
+        ("second", b"remove\nkeep\n"),
+        ("removed", b"gone\n"),
+        ("rename-old", b"move\n"),
+        ("binary", b"\0old"),
+        ("mode", b"script\n"),
+        ("crlf", b"a\r\n"),
+        ("eof", b"same\n"),
+    ] {
+        fs::write(root.join(path), bytes).unwrap();
+    }
+    git(&root, &["add", "."]);
+    git(&root, &["commit", "-m", "before"]);
+    let before = revision(&git(&root, &["rev-parse", "HEAD"]), RepoKind::Git);
+    for (path, bytes) in [
+        ("first", &b"new\nextra\nkeep\n"[..]),
+        ("second", b"keep\n"),
+        ("added", b"one\nlast"),
+        ("binary", b"\0new"),
+        ("crlf", b"b\r\n"),
+        ("eof", b"same"),
+    ] {
+        fs::write(root.join(path), bytes).unwrap();
+    }
+    fs::remove_file(root.join("removed")).unwrap();
+    fs::rename(root.join("rename-old"), root.join("-renamed\t\n")).unwrap();
+    fs::set_permissions(root.join("mode"), fs::Permissions::from_mode(0o755)).unwrap();
+    let mut repository = open(&root);
+    let catalog = repository
+        .compare(
+            1,
+            &before,
+            &working(RepoKind::Git),
+            ComparisonMode::Snapshots,
+            &[],
+        )
+        .unwrap();
+    assert!(catalog.files.iter().all(|file| !file.loaded
+        && file.before.is_empty()
+        && file.after.is_empty()
+        && file.hunks.is_empty()));
+    for (path, counts) in [
+        ("first", (2, 1)),
+        ("second", (0, 1)),
+        ("added", (2, 0)),
+        ("removed", (0, 1)),
+        ("-renamed\t\n", (0, 0)),
+        ("binary", (0, 0)),
+        ("mode", (0, 0)),
+        ("crlf", (1, 1)),
+        ("eof", (1, 1)),
+    ] {
+        assert_eq!(
+            changed(&catalog, Path::new(path)).stats,
+            Some(counts),
+            "{path}"
+        );
+    }
+    assert_eq!(
+        changed(&catalog, Path::new("-renamed\t\n")).status,
+        FileStatus::Renamed
+    );
+    fs::write(root.join("second"), "changed after freezing\n").unwrap();
+    for (index, file) in catalog.files.iter().enumerate() {
+        let loaded = repository.load_file(1, index).unwrap();
+        let counts = loaded.hunks.iter().fold((0, 0), |(added, removed), hunk| {
+            (added + hunk.after_len, removed + hunk.before_len)
+        });
+        assert_eq!(file.stats, Some(counts), "{}", file.path.display());
+    }
+    git(&root, &["add", "-A"]);
+    git(&root, &["commit", "-m", "advance checkout"]);
+    let refreshed = repository
+        .refresh_checkout(1, 2, true, &[])
+        .unwrap()
+        .map(checkout_comparison)
+        .unwrap();
+    assert_eq!(changed(&refreshed, Path::new("first")).stats, Some((2, 1)));
+    assert_eq!(changed(&refreshed, Path::new("second")).stats, Some((1, 2)));
+}
+
 #[test]
 fn git_working_reads_disk_and_handles_ranges_ignored_files_binary_links_and_odd_paths() {
     let fixture = Fixture::new();
@@ -1710,6 +1797,8 @@ fn jj_conflicted_revisions_show_cli_projection_and_keep_ordinary_files_navigable
             &[],
         )
         .unwrap();
+    assert_eq!(changed(&branch, Path::new("conflict")).stats, None);
+    assert_eq!(changed(&branch, Path::new("ordinary")).stats, Some((1, 1)));
     let index = branch
         .files
         .iter()
@@ -2003,6 +2092,8 @@ fn comparison_size_and_line_ceilings_are_lazy_and_explicit() {
         .unwrap();
     assert_eq!(catalog.files.len(), 3);
     assert!(catalog.files.iter().all(|file| !file.loaded));
+    assert_eq!(changed(&catalog, Path::new("too-many-bytes")).stats, None);
+    assert_eq!(changed(&catalog, Path::new("selected")).stats, Some((1, 0)));
     for (index, entry) in catalog.files.iter().enumerate() {
         match entry.path.to_str().unwrap() {
             "selected" => assert_eq!(