ZIm/crates/git_ui/src/project_diff.rs

use crate::{
    conflict_view::ConflictAddon,
    git_panel::{GitPanel, GitPanelAddon, GitStatusEntry},
    git_panel_settings::GitPanelSettings,
    remote_button::{render_publish_button, render_push_button},
};
use anyhow::Result;
use buffer_diff::{BufferDiff, DiffHunkSecondaryStatus};
use collections::HashSet;
use editor::{
    Editor, EditorEvent, SelectionEffects,
    actions::{GoToHunk, GoToPreviousHunk},
    scroll::Autoscroll,
};
use futures::StreamExt;
use git::{
    Commit, StageAll, StageAndNext, ToggleStaged, UnstageAll, UnstageAndNext,
    repository::{Branch, Upstream, UpstreamTracking, UpstreamTrackingStatus},
    status::FileStatus,
};
use gpui::{
    Action, AnyElement, AnyView, App, AppContext as _, AsyncWindowContext, Entity, EventEmitter,
    FocusHandle, Focusable, Render, Subscription, Task, WeakEntity, actions,
};
use language::{Anchor, Buffer, Capability, OffsetRangeExt};
use multi_buffer::{MultiBuffer, PathKey};
use project::{
    Project, ProjectPath,
    git_store::{GitStore, GitStoreEvent, RepositoryEvent},
};
use settings::{Settings, SettingsStore};
use std::any::{Any, TypeId};
use std::ops::Range;
use theme::ActiveTheme;
use ui::{KeyBinding, Tooltip, prelude::*, vertical_divider};
use util::ResultExt as _;
use workspace::{
    CloseActiveItem, ItemNavHistory, SerializableItem, ToolbarItemEvent, ToolbarItemLocation,
    ToolbarItemView, Workspace,
    item::{BreadcrumbText, Item, ItemEvent, ItemHandle, SaveOptions, TabContentParams},
    searchable::SearchableItemHandle,
};

actions!(
    git,
    [
        /// Shows the diff between the working directory and the index.
        Diff,
        /// Adds files to the git staging area.
        Add
    ]
);

pub struct ProjectDiff {
    project: Entity<Project>,
    multibuffer: Entity<MultiBuffer>,
    editor: Entity<Editor>,
    git_store: Entity<GitStore>,
    workspace: WeakEntity<Workspace>,
    focus_handle: FocusHandle,
    update_needed: postage::watch::Sender<()>,
    pending_scroll: Option<PathKey>,
    _task: Task<Result<()>>,
    _subscription: Subscription,
}

#[derive(Debug)]
struct DiffBuffer {
    path_key: PathKey,
    buffer: Entity<Buffer>,
    diff: Entity<BufferDiff>,
    file_status: FileStatus,
}

const CONFLICT_NAMESPACE: u32 = 1;
const TRACKED_NAMESPACE: u32 = 2;
const NEW_NAMESPACE: u32 = 3;

impl ProjectDiff {
    pub(crate) fn register(workspace: &mut Workspace, cx: &mut Context<Workspace>) {
        workspace.register_action(Self::deploy);
        workspace.register_action(|workspace, _: &Add, window, cx| {
            Self::deploy(workspace, &Diff, window, cx);
        });
        workspace::register_serializable_item::<ProjectDiff>(cx);
    }

    fn deploy(
        workspace: &mut Workspace,
        _: &Diff,
        window: &mut Window,
        cx: &mut Context<Workspace>,
    ) {
        Self::deploy_at(workspace, None, window, cx)
    }

    pub fn deploy_at(
        workspace: &mut Workspace,
        entry: Option<GitStatusEntry>,
        window: &mut Window,
        cx: &mut Context<Workspace>,
    ) {
        telemetry::event!(
            "Git Diff Opened",
            source = if entry.is_some() {
                "Git Panel"
            } else {
                "Action"
            }
        );
        let project_diff = if let Some(existing) = workspace.item_of_type::<Self>(cx) {
            workspace.activate_item(&existing, true, true, window, cx);
            existing
        } else {
            let workspace_handle = cx.entity();
            let project_diff =
                cx.new(|cx| Self::new(workspace.project().clone(), workspace_handle, window, cx));
            workspace.add_item_to_active_pane(
                Box::new(project_diff.clone()),
                None,
                true,
                window,
                cx,
            );
            project_diff
        };
        if let Some(entry) = entry {
            project_diff.update(cx, |project_diff, cx| {
                project_diff.move_to_entry(entry, window, cx);
            })
        }
    }

    pub fn autoscroll(&self, cx: &mut Context<Self>) {
        self.editor.update(cx, |editor, cx| {
            editor.request_autoscroll(Autoscroll::fit(), cx);
        })
    }

    fn new(
        project: Entity<Project>,
        workspace: Entity<Workspace>,
        window: &mut Window,
        cx: &mut Context<Self>,
    ) -> Self {
        let focus_handle = cx.focus_handle();
        let multibuffer = cx.new(|_| MultiBuffer::new(Capability::ReadWrite));

        let editor = cx.new(|cx| {
            let mut diff_display_editor =
                Editor::for_multibuffer(multibuffer.clone(), Some(project.clone()), window, cx);
            diff_display_editor.disable_diagnostics(cx);
            diff_display_editor.set_expand_all_diff_hunks(cx);
            diff_display_editor.register_addon(GitPanelAddon {
                workspace: workspace.downgrade(),
            });
            diff_display_editor
        });
        window.defer(cx, {
            let workspace = workspace.clone();
            let editor = editor.clone();
            move |window, cx| {
                workspace.update(cx, |workspace, cx| {
                    editor.update(cx, |editor, cx| {
                        editor.added_to_workspace(workspace, window, cx);
                    })
                });
            }
        });
        cx.subscribe_in(&editor, window, Self::handle_editor_event)
            .detach();

        let git_store = project.read(cx).git_store().clone();
        let git_store_subscription = cx.subscribe_in(
            &git_store,
            window,
            move |this, _git_store, event, _window, _cx| match event {
                GitStoreEvent::ActiveRepositoryChanged(_)
                | GitStoreEvent::RepositoryUpdated(_, RepositoryEvent::Updated { .. }, true)
                | GitStoreEvent::ConflictsUpdated => {
                    *this.update_needed.borrow_mut() = ();
                }
                _ => {}
            },
        );

        let mut was_sort_by_path = GitPanelSettings::get_global(cx).sort_by_path;
        let mut was_collapse_untracked_diff =
            GitPanelSettings::get_global(cx).collapse_untracked_diff;
        cx.observe_global::<SettingsStore>(move |this, cx| {
            let is_sort_by_path = GitPanelSettings::get_global(cx).sort_by_path;
            let is_collapse_untracked_diff =
                GitPanelSettings::get_global(cx).collapse_untracked_diff;
            if is_sort_by_path != was_sort_by_path
                || is_collapse_untracked_diff != was_collapse_untracked_diff
            {
                *this.update_needed.borrow_mut() = ();
            }
            was_sort_by_path = is_sort_by_path;
            was_collapse_untracked_diff = is_collapse_untracked_diff;
        })
        .detach();

        let (mut send, recv) = postage::watch::channel::<()>();
        let worker = window.spawn(cx, {
            let this = cx.weak_entity();
            async |cx| Self::handle_status_updates(this, recv, cx).await
        });
        // Kick off a refresh immediately
        *send.borrow_mut() = ();

        Self {
            project,
            git_store: git_store.clone(),
            workspace: workspace.downgrade(),
            focus_handle,
            editor,
            multibuffer,
            pending_scroll: None,
            update_needed: send,
            _task: worker,
            _subscription: git_store_subscription,
        }
    }

    pub fn move_to_entry(
        &mut self,
        entry: GitStatusEntry,
        window: &mut Window,
        cx: &mut Context<Self>,
    ) {
        let Some(git_repo) = self.git_store.read(cx).active_repository() else {
            return;
        };
        let repo = git_repo.read(cx);

        let namespace = if repo.had_conflict_on_last_merge_head_change(&entry.repo_path) {
            CONFLICT_NAMESPACE
        } else if entry.status.is_created() {
            NEW_NAMESPACE
        } else {
            TRACKED_NAMESPACE
        };

        let path_key = PathKey::namespaced(namespace, entry.repo_path.0.clone());

        self.move_to_path(path_key, window, cx)
    }

    pub fn active_path(&self, cx: &App) -> Option<ProjectPath> {
        let editor = self.editor.read(cx);
        let position = editor.selections.newest_anchor().head();
        let multi_buffer = editor.buffer().read(cx);
        let (_, buffer, _) = multi_buffer.excerpt_containing(position, cx)?;

        let file = buffer.read(cx).file()?;
        Some(ProjectPath {
            worktree_id: file.worktree_id(cx),
            path: file.path().clone(),
        })
    }

    fn move_to_path(&mut self, path_key: PathKey, window: &mut Window, cx: &mut Context<Self>) {
        if let Some(position) = self.multibuffer.read(cx).location_for_path(&path_key, cx) {
            self.editor.update(cx, |editor, cx| {
                editor.change_selections(
                    SelectionEffects::scroll(Autoscroll::focused()),
                    window,
                    cx,
                    |s| {
                        s.select_ranges([position..position]);
                    },
                )
            });
        } else {
            self.pending_scroll = Some(path_key);
        }
    }

    fn button_states(&self, cx: &App) -> ButtonStates {
        let editor = self.editor.read(cx);
        let snapshot = self.multibuffer.read(cx).snapshot(cx);
        let prev_next = snapshot.diff_hunks().nth(1).is_some();
        let mut selection = true;

        let mut ranges = editor
            .selections
            .disjoint_anchor_ranges()
            .collect::<Vec<_>>();
        if !ranges.iter().any(|range| range.start != range.end) {
            selection = false;
            if let Some((excerpt_id, buffer, range)) = self.editor.read(cx).active_excerpt(cx) {
                ranges = vec![multi_buffer::Anchor::range_in_buffer(
                    excerpt_id,
                    buffer.read(cx).remote_id(),
                    range,
                )];
            } else {
                ranges = Vec::default();
            }
        }
        let mut has_staged_hunks = false;
        let mut has_unstaged_hunks = false;
        for hunk in editor.diff_hunks_in_ranges(&ranges, &snapshot) {
            match hunk.secondary_status {
                DiffHunkSecondaryStatus::HasSecondaryHunk
                | DiffHunkSecondaryStatus::SecondaryHunkAdditionPending => {
                    has_unstaged_hunks = true;
                }
                DiffHunkSecondaryStatus::OverlapsWithSecondaryHunk => {
                    has_staged_hunks = true;
                    has_unstaged_hunks = true;
                }
                DiffHunkSecondaryStatus::NoSecondaryHunk
                | DiffHunkSecondaryStatus::SecondaryHunkRemovalPending => {
                    has_staged_hunks = true;
                }
            }
        }
        let mut stage_all = false;
        let mut unstage_all = false;
        self.workspace
            .read_with(cx, |workspace, cx| {
                if let Some(git_panel) = workspace.panel::<GitPanel>(cx) {
                    let git_panel = git_panel.read(cx);
                    stage_all = git_panel.can_stage_all();
                    unstage_all = git_panel.can_unstage_all();
                }
            })
            .ok();

        ButtonStates {
            stage: has_unstaged_hunks,
            unstage: has_staged_hunks,
            prev_next,
            selection,
            stage_all,
            unstage_all,
        }
    }

    fn handle_editor_event(
        &mut self,
        editor: &Entity<Editor>,
        event: &EditorEvent,
        window: &mut Window,
        cx: &mut Context<Self>,
    ) {
        if let EditorEvent::SelectionsChanged { local: true } = event {
            let Some(project_path) = self.active_path(cx) else {
                return;
            };
            self.workspace
                .update(cx, |workspace, cx| {
                    if let Some(git_panel) = workspace.panel::<GitPanel>(cx) {
                        git_panel.update(cx, |git_panel, cx| {
                            git_panel.select_entry_by_path(project_path, window, cx)
                        })
                    }
                })
                .ok();
        }
        if editor.focus_handle(cx).contains_focused(window, cx)
            && self.multibuffer.read(cx).is_empty()
        {
            self.focus_handle.focus(window)
        }
    }

    fn load_buffers(&mut self, cx: &mut Context<Self>) -> Vec<Task<Result<DiffBuffer>>> {
        let Some(repo) = self.git_store.read(cx).active_repository() else {
            self.multibuffer.update(cx, |multibuffer, cx| {
                multibuffer.clear(cx);
            });
            return vec![];
        };

        let mut previous_paths = self.multibuffer.read(cx).paths().collect::<HashSet<_>>();

        let mut result = vec![];
        repo.update(cx, |repo, cx| {
            for entry in repo.cached_status() {
                if !entry.status.has_changes() {
                    continue;
                }
                let Some(project_path) = repo.repo_path_to_project_path(&entry.repo_path, cx)
                else {
                    continue;
                };
                let namespace = if GitPanelSettings::get_global(cx).sort_by_path {
                    TRACKED_NAMESPACE
                } else if repo.had_conflict_on_last_merge_head_change(&entry.repo_path) {
                    CONFLICT_NAMESPACE
                } else if entry.status.is_created() {
                    NEW_NAMESPACE
                } else {
                    TRACKED_NAMESPACE
                };
                let path_key = PathKey::namespaced(namespace, entry.repo_path.0.clone());

                previous_paths.remove(&path_key);
                let load_buffer = self
                    .project
                    .update(cx, |project, cx| project.open_buffer(project_path, cx));

                let project = self.project.clone();
                result.push(cx.spawn(async move |_, cx| {
                    let buffer = load_buffer.await?;
                    let changes = project
                        .update(cx, |project, cx| {
                            project.open_uncommitted_diff(buffer.clone(), cx)
                        })?
                        .await?;
                    Ok(DiffBuffer {
                        path_key,
                        buffer,
                        diff: changes,
                        file_status: entry.status,
                    })
                }));
            }
        });
        self.multibuffer.update(cx, |multibuffer, cx| {
            for path in previous_paths {
                multibuffer.remove_excerpts_for_path(path, cx);
            }
        });
        result
    }

    fn register_buffer(
        &mut self,
        diff_buffer: DiffBuffer,
        window: &mut Window,
        cx: &mut Context<Self>,
    ) {
        let path_key = diff_buffer.path_key;
        let buffer = diff_buffer.buffer;
        let diff = diff_buffer.diff;

        let conflict_addon = self
            .editor
            .read(cx)
            .addon::<ConflictAddon>()
            .expect("project diff editor should have a conflict addon");

        let snapshot = buffer.read(cx).snapshot();
        let diff = diff.read(cx);
        let diff_hunk_ranges = diff
            .hunks_intersecting_range(Anchor::MIN..Anchor::MAX, &snapshot, cx)
            .map(|diff_hunk| diff_hunk.buffer_range.clone());
        let conflicts = conflict_addon
            .conflict_set(snapshot.remote_id())
            .map(|conflict_set| conflict_set.read(cx).snapshot().conflicts.clone())
            .unwrap_or_default();
        let conflicts = conflicts.iter().map(|conflict| conflict.range.clone());

        let excerpt_ranges = merge_anchor_ranges(diff_hunk_ranges, conflicts, &snapshot)
            .map(|range| range.to_point(&snapshot))
            .collect::<Vec<_>>();

        let (was_empty, is_excerpt_newly_added) = self.multibuffer.update(cx, |multibuffer, cx| {
            let was_empty = multibuffer.is_empty();
            let (_, is_newly_added) = multibuffer.set_excerpts_for_path(
                path_key.clone(),
                buffer,
                excerpt_ranges,
                editor::DEFAULT_MULTIBUFFER_CONTEXT,
                cx,
            );
            (was_empty, is_newly_added)
        });

        self.editor.update(cx, |editor, cx| {
            if was_empty {
                editor.change_selections(SelectionEffects::no_scroll(), window, cx, |selections| {
                    // TODO select the very beginning (possibly inside a deletion)
                    selections.select_ranges([0..0])
                });
            }
            if is_excerpt_newly_added
                && (diff_buffer.file_status.is_deleted()
                    || (diff_buffer.file_status.is_untracked()
                        && GitPanelSettings::get_global(cx).collapse_untracked_diff))
            {
                editor.fold_buffer(snapshot.text.remote_id(), cx)
            }
        });

        if self.multibuffer.read(cx).is_empty()
            && self
                .editor
                .read(cx)
                .focus_handle(cx)
                .contains_focused(window, cx)
        {
            self.focus_handle.focus(window);
        } else if self.focus_handle.is_focused(window) && !self.multibuffer.read(cx).is_empty() {
            self.editor.update(cx, |editor, cx| {
                editor.focus_handle(cx).focus(window);
            });
        }
        if self.pending_scroll.as_ref() == Some(&path_key) {
            self.move_to_path(path_key, window, cx);
        }
    }

    pub async fn handle_status_updates(
        this: WeakEntity<Self>,
        mut recv: postage::watch::Receiver<()>,
        cx: &mut AsyncWindowContext,
    ) -> Result<()> {
        while (recv.next().await).is_some() {
            let buffers_to_load = this.update(cx, |this, cx| this.load_buffers(cx))?;
            for buffer_to_load in buffers_to_load {
                if let Some(buffer) = buffer_to_load.await.log_err() {
                    cx.update(|window, cx| {
                        this.update(cx, |this, cx| this.register_buffer(buffer, window, cx))
                            .ok();
                    })?;
                }
            }
            this.update(cx, |this, cx| {
                this.pending_scroll.take();
                cx.notify();
            })?;
        }

        Ok(())
    }

    #[cfg(any(test, feature = "test-support"))]
    pub fn excerpt_paths(&self, cx: &App) -> Vec<String> {
        self.multibuffer
            .read(cx)
            .excerpt_paths()
            .map(|key| key.path().to_string_lossy().to_string())
            .collect()
    }
}

impl EventEmitter<EditorEvent> for ProjectDiff {}

impl Focusable for ProjectDiff {
    fn focus_handle(&self, cx: &App) -> FocusHandle {
        if self.multibuffer.read(cx).is_empty() {
            self.focus_handle.clone()
        } else {
            self.editor.focus_handle(cx)
        }
    }
}

impl Item for ProjectDiff {
    type Event = EditorEvent;

    fn tab_icon(&self, _window: &Window, _cx: &App) -> Option<Icon> {
        Some(Icon::new(IconName::GitBranch).color(Color::Muted))
    }

    fn to_item_events(event: &EditorEvent, f: impl FnMut(ItemEvent)) {
        Editor::to_item_events(event, f)
    }

    fn deactivated(&mut self, window: &mut Window, cx: &mut Context<Self>) {
        self.editor
            .update(cx, |editor, cx| editor.deactivated(window, cx));
    }

    fn navigate(
        &mut self,
        data: Box<dyn Any>,
        window: &mut Window,
        cx: &mut Context<Self>,
    ) -> bool {
        self.editor
            .update(cx, |editor, cx| editor.navigate(data, window, cx))
    }

    fn tab_tooltip_text(&self, _: &App) -> Option<SharedString> {
        Some("Project Diff".into())
    }

    fn tab_content(&self, params: TabContentParams, _window: &Window, _: &App) -> AnyElement {
        Label::new("Uncommitted Changes")
            .color(if params.selected {
                Color::Default
            } else {
                Color::Muted
            })
            .into_any_element()
    }

    fn tab_content_text(&self, _detail: usize, _: &App) -> SharedString {
        "Uncommitted Changes".into()
    }

    fn telemetry_event_text(&self) -> Option<&'static str> {
        Some("Project Diff Opened")
    }

    fn as_searchable(&self, _: &Entity<Self>) -> Option<Box<dyn SearchableItemHandle>> {
        Some(Box::new(self.editor.clone()))
    }

    fn for_each_project_item(
        &self,
        cx: &App,
        f: &mut dyn FnMut(gpui::EntityId, &dyn project::ProjectItem),
    ) {
        self.editor.for_each_project_item(cx, f)
    }

    fn is_singleton(&self, _: &App) -> bool {
        false
    }

    fn set_nav_history(
        &mut self,
        nav_history: ItemNavHistory,
        _: &mut Window,
        cx: &mut Context<Self>,
    ) {
        self.editor.update(cx, |editor, _| {
            editor.set_nav_history(Some(nav_history));
        });
    }

    fn clone_on_split(
        &self,
        _workspace_id: Option<workspace::WorkspaceId>,
        window: &mut Window,
        cx: &mut Context<Self>,
    ) -> Option<Entity<Self>>
    where
        Self: Sized,
    {
        let workspace = self.workspace.upgrade()?;
        Some(cx.new(|cx| ProjectDiff::new(self.project.clone(), workspace, window, cx)))
    }

    fn is_dirty(&self, cx: &App) -> bool {
        self.multibuffer.read(cx).is_dirty(cx)
    }

    fn has_conflict(&self, cx: &App) -> bool {
        self.multibuffer.read(cx).has_conflict(cx)
    }

    fn can_save(&self, _: &App) -> bool {
        true
    }

    fn save(
        &mut self,
        options: SaveOptions,
        project: Entity<Project>,
        window: &mut Window,
        cx: &mut Context<Self>,
    ) -> Task<Result<()>> {
        self.editor.save(options, project, window, cx)
    }

    fn save_as(
        &mut self,
        _: Entity<Project>,
        _: ProjectPath,
        _window: &mut Window,
        _: &mut Context<Self>,
    ) -> Task<Result<()>> {
        unreachable!()
    }

    fn reload(
        &mut self,
        project: Entity<Project>,
        window: &mut Window,
        cx: &mut Context<Self>,
    ) -> Task<Result<()>> {
        self.editor.reload(project, window, cx)
    }

    fn act_as_type<'a>(
        &'a self,
        type_id: TypeId,
        self_handle: &'a Entity<Self>,
        _: &'a App,
    ) -> Option<AnyView> {
        if type_id == TypeId::of::<Self>() {
            Some(self_handle.to_any())
        } else if type_id == TypeId::of::<Editor>() {
            Some(self.editor.to_any())
        } else {
            None
        }
    }

    fn breadcrumb_location(&self, _: &App) -> ToolbarItemLocation {
        ToolbarItemLocation::PrimaryLeft
    }

    fn breadcrumbs(&self, theme: &theme::Theme, cx: &App) -> Option<Vec<BreadcrumbText>> {
        self.editor.breadcrumbs(theme, cx)
    }

    fn added_to_workspace(
        &mut self,
        workspace: &mut Workspace,
        window: &mut Window,
        cx: &mut Context<Self>,
    ) {
        self.editor.update(cx, |editor, cx| {
            editor.added_to_workspace(workspace, window, cx)
        });
    }
}

impl Render for ProjectDiff {
    fn render(&mut self, window: &mut Window, cx: &mut Context<Self>) -> impl IntoElement {
        let is_empty = self.multibuffer.read(cx).is_empty();

        div()
            .track_focus(&self.focus_handle)
            .key_context(if is_empty { "EmptyPane" } else { "GitDiff" })
            .bg(cx.theme().colors().editor_background)
            .flex()
            .items_center()
            .justify_center()
            .size_full()
            .when(is_empty, |el| {
                let remote_button = if let Some(panel) = self
                    .workspace
                    .upgrade()
                    .and_then(|workspace| workspace.read(cx).panel::<GitPanel>(cx))
                {
                    panel.update(cx, |panel, cx| panel.render_remote_button(cx))
                } else {
                    None
                };
                let keybinding_focus_handle = self.focus_handle(cx).clone();
                el.child(
                    v_flex()
                        .gap_1()
                        .child(
                            h_flex()
                                .justify_around()
                                .child(Label::new("No uncommitted changes")),
                        )
                        .map(|el| match remote_button {
                            Some(button) => el.child(h_flex().justify_around().child(button)),
                            None => el.child(
                                h_flex()
                                    .justify_around()
                                    .child(Label::new("Remote up to date")),
                            ),
                        })
                        .child(
                            h_flex().justify_around().mt_1().child(
                                Button::new("project-diff-close-button", "Close")
                                    // .style(ButtonStyle::Transparent)
                                    .key_binding(KeyBinding::for_action_in(
                                        &CloseActiveItem::default(),
                                        &keybinding_focus_handle,
                                        window,
                                        cx,
                                    ))
                                    .on_click(move |_, window, cx| {
                                        window.focus(&keybinding_focus_handle);
                                        window.dispatch_action(
                                            Box::new(CloseActiveItem::default()),
                                            cx,
                                        );
                                    }),
                            ),
                        ),
                )
            })
            .when(!is_empty, |el| el.child(self.editor.clone()))
    }
}

impl SerializableItem for ProjectDiff {
    fn serialized_item_kind() -> &'static str {
        "ProjectDiff"
    }

    fn cleanup(
        _: workspace::WorkspaceId,
        _: Vec<workspace::ItemId>,
        _: &mut Window,
        _: &mut App,
    ) -> Task<Result<()>> {
        Task::ready(Ok(()))
    }

    fn deserialize(
        _project: Entity<Project>,
        workspace: WeakEntity<Workspace>,
        _workspace_id: workspace::WorkspaceId,
        _item_id: workspace::ItemId,
        window: &mut Window,
        cx: &mut App,
    ) -> Task<Result<Entity<Self>>> {
        window.spawn(cx, async move |cx| {
            workspace.update_in(cx, |workspace, window, cx| {
                let workspace_handle = cx.entity();
                cx.new(|cx| Self::new(workspace.project().clone(), workspace_handle, window, cx))
            })
        })
    }

    fn serialize(
        &mut self,
        _workspace: &mut Workspace,
        _item_id: workspace::ItemId,
        _closing: bool,
        _window: &mut Window,
        _cx: &mut Context<Self>,
    ) -> Option<Task<Result<()>>> {
        None
    }

    fn should_serialize(&self, _: &Self::Event) -> bool {
        false
    }
}

pub struct ProjectDiffToolbar {
    project_diff: Option<WeakEntity<ProjectDiff>>,
    workspace: WeakEntity<Workspace>,
}

impl ProjectDiffToolbar {
    pub fn new(workspace: &Workspace, _: &mut Context<Self>) -> Self {
        Self {
            project_diff: None,
            workspace: workspace.weak_handle(),
        }
    }

    fn project_diff(&self, _: &App) -> Option<Entity<ProjectDiff>> {
        self.project_diff.as_ref()?.upgrade()
    }

    fn dispatch_action(&self, action: &dyn Action, window: &mut Window, cx: &mut Context<Self>) {
        if let Some(project_diff) = self.project_diff(cx) {
            project_diff.focus_handle(cx).focus(window);
        }
        let action = action.boxed_clone();
        cx.defer(move |cx| {
            cx.dispatch_action(action.as_ref());
        })
    }

    fn stage_all(&mut self, window: &mut Window, cx: &mut Context<Self>) {
        self.workspace
            .update(cx, |workspace, cx| {
                if let Some(panel) = workspace.panel::<GitPanel>(cx) {
                    panel.update(cx, |panel, cx| {
                        panel.stage_all(&Default::default(), window, cx);
                    });
                }
            })
            .ok();
    }

    fn unstage_all(&mut self, window: &mut Window, cx: &mut Context<Self>) {
        self.workspace
            .update(cx, |workspace, cx| {
                let Some(panel) = workspace.panel::<GitPanel>(cx) else {
                    return;
                };
                panel.update(cx, |panel, cx| {
                    panel.unstage_all(&Default::default(), window, cx);
                });
            })
            .ok();
    }
}

impl EventEmitter<ToolbarItemEvent> for ProjectDiffToolbar {}

impl ToolbarItemView for ProjectDiffToolbar {
    fn set_active_pane_item(
        &mut self,
        active_pane_item: Option<&dyn ItemHandle>,
        _: &mut Window,
        cx: &mut Context<Self>,
    ) -> ToolbarItemLocation {
        self.project_diff = active_pane_item
            .and_then(|item| item.act_as::<ProjectDiff>(cx))
            .map(|entity| entity.downgrade());
        if self.project_diff.is_some() {
            ToolbarItemLocation::PrimaryRight
        } else {
            ToolbarItemLocation::Hidden
        }
    }

    fn pane_focus_update(
        &mut self,
        _pane_focused: bool,
        _window: &mut Window,
        _cx: &mut Context<Self>,
    ) {
    }
}

struct ButtonStates {
    stage: bool,
    unstage: bool,
    prev_next: bool,
    selection: bool,
    stage_all: bool,
    unstage_all: bool,
}

impl Render for ProjectDiffToolbar {
    fn render(&mut self, _: &mut Window, cx: &mut Context<Self>) -> impl IntoElement {
        let Some(project_diff) = self.project_diff(cx) else {
            return div();
        };
        let focus_handle = project_diff.focus_handle(cx);
        let button_states = project_diff.read(cx).button_states(cx);

        h_group_xl()
            .my_neg_1()
            .py_1()
            .items_center()
            .flex_wrap()
            .justify_between()
            .child(
                h_group_sm()
                    .when(button_states.selection, |el| {
                        el.child(
                            Button::new("stage", "Toggle Staged")
                                .tooltip(Tooltip::for_action_title_in(
                                    "Toggle Staged",
                                    &ToggleStaged,
                                    &focus_handle,
                                ))
                                .disabled(!button_states.stage && !button_states.unstage)
                                .on_click(cx.listener(|this, _, window, cx| {
                                    this.dispatch_action(&ToggleStaged, window, cx)
                                })),
                        )
                    })
                    .when(!button_states.selection, |el| {
                        el.child(
                            Button::new("stage", "Stage")
                                .tooltip(Tooltip::for_action_title_in(
                                    "Stage and go to next hunk",
                                    &StageAndNext,
                                    &focus_handle,
                                ))
                                .on_click(cx.listener(|this, _, window, cx| {
                                    this.dispatch_action(&StageAndNext, window, cx)
                                })),
                        )
                        .child(
                            Button::new("unstage", "Unstage")
                                .tooltip(Tooltip::for_action_title_in(
                                    "Unstage and go to next hunk",
                                    &UnstageAndNext,
                                    &focus_handle,
                                ))
                                .on_click(cx.listener(|this, _, window, cx| {
                                    this.dispatch_action(&UnstageAndNext, window, cx)
                                })),
                        )
                    }),
            )
            // n.b. the only reason these arrows are here is because we don't
            // support "undo" for staging so we need a way to go back.
            .child(
                h_group_sm()
                    .child(
                        IconButton::new("up", IconName::ArrowUp)
                            .shape(ui::IconButtonShape::Square)
                            .tooltip(Tooltip::for_action_title_in(
                                "Go to previous hunk",
                                &GoToPreviousHunk,
                                &focus_handle,
                            ))
                            .disabled(!button_states.prev_next)
                            .on_click(cx.listener(|this, _, window, cx| {
                                this.dispatch_action(&GoToPreviousHunk, window, cx)
                            })),
                    )
                    .child(
                        IconButton::new("down", IconName::ArrowDown)
                            .shape(ui::IconButtonShape::Square)
                            .tooltip(Tooltip::for_action_title_in(
                                "Go to next hunk",
                                &GoToHunk,
                                &focus_handle,
                            ))
                            .disabled(!button_states.prev_next)
                            .on_click(cx.listener(|this, _, window, cx| {
                                this.dispatch_action(&GoToHunk, window, cx)
                            })),
                    ),
            )
            .child(vertical_divider())
            .child(
                h_group_sm()
                    .when(
                        button_states.unstage_all && !button_states.stage_all,
                        |el| {
                            el.child(
                                Button::new("unstage-all", "Unstage All")
                                    .tooltip(Tooltip::for_action_title_in(
                                        "Unstage all changes",
                                        &UnstageAll,
                                        &focus_handle,
                                    ))
                                    .on_click(cx.listener(|this, _, window, cx| {
                                        this.unstage_all(window, cx)
                                    })),
                            )
                        },
                    )
                    .when(
                        !button_states.unstage_all || button_states.stage_all,
                        |el| {
                            el.child(
                                // todo make it so that changing to say "Unstaged"
                                // doesn't change the position.
                                div().child(
                                    Button::new("stage-all", "Stage All")
                                        .disabled(!button_states.stage_all)
                                        .tooltip(Tooltip::for_action_title_in(
                                            "Stage all changes",
                                            &StageAll,
                                            &focus_handle,
                                        ))
                                        .on_click(cx.listener(|this, _, window, cx| {
                                            this.stage_all(window, cx)
                                        })),
                                ),
                            )
                        },
                    )
                    .child(
                        Button::new("commit", "Commit")
                            .tooltip(Tooltip::for_action_title_in(
                                "Commit",
                                &Commit,
                                &focus_handle,
                            ))
                            .on_click(cx.listener(|this, _, window, cx| {
                                this.dispatch_action(&Commit, window, cx);
                            })),
                    ),
            )
    }
}

#[derive(IntoElement, RegisterComponent)]
pub struct ProjectDiffEmptyState {
    pub no_repo: bool,
    pub can_push_and_pull: bool,
    pub focus_handle: Option<FocusHandle>,
    pub current_branch: Option<Branch>,
    // has_pending_commits: bool,
    // ahead_of_remote: bool,
    // no_git_repository: bool,
}

impl RenderOnce for ProjectDiffEmptyState {
    fn render(self, _window: &mut Window, cx: &mut App) -> impl IntoElement {
        let status_against_remote = |ahead_by: usize, behind_by: usize| -> bool {
            match self.current_branch {
                Some(Branch {
                    upstream:
                        Some(Upstream {
                            tracking:
                                UpstreamTracking::Tracked(UpstreamTrackingStatus {
                                    ahead, behind, ..
                                }),
                            ..
                        }),
                    ..
                }) if (ahead > 0) == (ahead_by > 0) && (behind > 0) == (behind_by > 0) => true,
                _ => false,
            }
        };

        let change_count = |current_branch: &Branch| -> (usize, usize) {
            match current_branch {
                Branch {
                    upstream:
                        Some(Upstream {
                            tracking:
                                UpstreamTracking::Tracked(UpstreamTrackingStatus {
                                    ahead, behind, ..
                                }),
                            ..
                        }),
                    ..
                } => (*ahead as usize, *behind as usize),
                _ => (0, 0),
            }
        };

        let not_ahead_or_behind = status_against_remote(0, 0);
        let ahead_of_remote = status_against_remote(1, 0);
        let branch_not_on_remote = if let Some(branch) = self.current_branch.as_ref() {
            branch.upstream.is_none()
        } else {
            false
        };

        let has_branch_container = |branch: &Branch| {
            h_flex()
                .max_w(px(420.))
                .bg(cx.theme().colors().text.opacity(0.05))
                .border_1()
                .border_color(cx.theme().colors().border)
                .rounded_sm()
                .gap_8()
                .px_6()
                .py_4()
                .map(|this| {
                    if ahead_of_remote {
                        let ahead_count = change_count(branch).0;
                        let ahead_string = format!("{} Commits Ahead", ahead_count);
                        this.child(
                            v_flex()
                                .child(Headline::new(ahead_string).size(HeadlineSize::Small))
                                .child(
                                    Label::new(format!("Push your changes to {}", branch.name()))
                                        .color(Color::Muted),
                                ),
                        )
                        .child(div().child(render_push_button(
                            self.focus_handle,
                            "push".into(),
                            ahead_count as u32,
                        )))
                    } else if branch_not_on_remote {
                        this.child(
                            v_flex()
                                .child(Headline::new("Publish Branch").size(HeadlineSize::Small))
                                .child(
                                    Label::new(format!("Create {} on remote", branch.name()))
                                        .color(Color::Muted),
                                ),
                        )
                        .child(
                            div().child(render_publish_button(self.focus_handle, "publish".into())),
                        )
                    } else {
                        this.child(Label::new("Remote status unknown").color(Color::Muted))
                    }
                })
        };

        v_flex().size_full().items_center().justify_center().child(
            v_flex()
                .gap_1()
                .when(self.no_repo, |this| {
                    // TODO: add git init
                    this.text_center()
                        .child(Label::new("No Repository").color(Color::Muted))
                })
                .map(|this| {
                    if not_ahead_or_behind && self.current_branch.is_some() {
                        this.text_center()
                            .child(Label::new("No Changes").color(Color::Muted))
                    } else {
                        this.when_some(self.current_branch.as_ref(), |this, branch| {
                            this.child(has_branch_container(branch))
                        })
                    }
                }),
        )
    }
}

mod preview {
    use git::repository::{
        Branch, CommitSummary, Upstream, UpstreamTracking, UpstreamTrackingStatus,
    };
    use ui::prelude::*;

    use super::ProjectDiffEmptyState;

    // View this component preview using `workspace: open component-preview`
    impl Component for ProjectDiffEmptyState {
        fn scope() -> ComponentScope {
            ComponentScope::VersionControl
        }

        fn preview(_window: &mut Window, _cx: &mut App) -> Option<AnyElement> {
            let unknown_upstream: Option<UpstreamTracking> = None;
            let ahead_of_upstream: Option<UpstreamTracking> = Some(
                UpstreamTrackingStatus {
                    ahead: 2,
                    behind: 0,
                }
                .into(),
            );

            let not_ahead_or_behind_upstream: Option<UpstreamTracking> = Some(
                UpstreamTrackingStatus {
                    ahead: 0,
                    behind: 0,
                }
                .into(),
            );

            fn branch(upstream: Option<UpstreamTracking>) -> Branch {
                Branch {
                    is_head: true,
                    ref_name: "some-branch".into(),
                    upstream: upstream.map(|tracking| Upstream {
                        ref_name: "origin/some-branch".into(),
                        tracking,
                    }),
                    most_recent_commit: Some(CommitSummary {
                        sha: "abc123".into(),
                        subject: "Modify stuff".into(),
                        commit_timestamp: 1710932954,
                        has_parent: true,
                    }),
                }
            }

            let no_repo_state = ProjectDiffEmptyState {
                no_repo: true,
                can_push_and_pull: false,
                focus_handle: None,
                current_branch: None,
            };

            let no_changes_state = ProjectDiffEmptyState {
                no_repo: false,
                can_push_and_pull: true,
                focus_handle: None,
                current_branch: Some(branch(not_ahead_or_behind_upstream)),
            };

            let ahead_of_upstream_state = ProjectDiffEmptyState {
                no_repo: false,
                can_push_and_pull: true,
                focus_handle: None,
                current_branch: Some(branch(ahead_of_upstream)),
            };

            let unknown_upstream_state = ProjectDiffEmptyState {
                no_repo: false,
                can_push_and_pull: true,
                focus_handle: None,
                current_branch: Some(branch(unknown_upstream)),
            };

            let (width, height) = (px(480.), px(320.));

            Some(
                v_flex()
                    .gap_6()
                    .children(vec![
                        example_group(vec![
                            single_example(
                                "No Repo",
                                div()
                                    .w(width)
                                    .h(height)
                                    .child(no_repo_state)
                                    .into_any_element(),
                            ),
                            single_example(
                                "No Changes",
                                div()
                                    .w(width)
                                    .h(height)
                                    .child(no_changes_state)
                                    .into_any_element(),
                            ),
                            single_example(
                                "Unknown Upstream",
                                div()
                                    .w(width)
                                    .h(height)
                                    .child(unknown_upstream_state)
                                    .into_any_element(),
                            ),
                            single_example(
                                "Ahead of Remote",
                                div()
                                    .w(width)
                                    .h(height)
                                    .child(ahead_of_upstream_state)
                                    .into_any_element(),
                            ),
                        ])
                        .vertical(),
                    ])
                    .into_any_element(),
            )
        }
    }
}

fn merge_anchor_ranges<'a>(
    left: impl 'a + Iterator<Item = Range<Anchor>>,
    right: impl 'a + Iterator<Item = Range<Anchor>>,
    snapshot: &'a language::BufferSnapshot,
) -> impl 'a + Iterator<Item = Range<Anchor>> {
    let mut left = left.fuse().peekable();
    let mut right = right.fuse().peekable();

    std::iter::from_fn(move || {
        let Some(left_range) = left.peek() else {
            return right.next();
        };
        let Some(right_range) = right.peek() else {
            return left.next();
        };

        let mut next_range = if left_range.start.cmp(&right_range.start, snapshot).is_lt() {
            left.next().unwrap()
        } else {
            right.next().unwrap()
        };

        // Extend the basic range while there's overlap with a range from either stream.
        loop {
            if let Some(left_range) = left
                .peek()
                .filter(|range| range.start.cmp(&next_range.end, snapshot).is_le())
                .cloned()
            {
                left.next();
                next_range.end = left_range.end;
            } else if let Some(right_range) = right
                .peek()
                .filter(|range| range.start.cmp(&next_range.end, snapshot).is_le())
                .cloned()
            {
                right.next();
                next_range.end = right_range.end;
            } else {
                break;
            }
        }

        Some(next_range)
    })
}

#[cfg(not(target_os = "windows"))]
#[cfg(test)]
mod tests {
    use db::indoc;
    use editor::test::editor_test_context::{EditorTestContext, assert_state_with_diff};
    use git::status::{UnmergedStatus, UnmergedStatusCode};
    use gpui::TestAppContext;
    use project::FakeFs;
    use serde_json::json;
    use settings::SettingsStore;
    use std::path::Path;
    use unindent::Unindent as _;
    use util::path;

    use super::*;

    #[ctor::ctor]
    fn init_logger() {
        zlog::init_test();
    }

    fn init_test(cx: &mut TestAppContext) {
        cx.update(|cx| {
            let store = SettingsStore::test(cx);
            cx.set_global(store);
            theme::init(theme::LoadThemes::JustBase, cx);
            language::init(cx);
            Project::init_settings(cx);
            workspace::init_settings(cx);
            editor::init(cx);
            crate::init(cx);
        });
    }

    #[gpui::test]
    async fn test_save_after_restore(cx: &mut TestAppContext) {
        init_test(cx);

        let fs = FakeFs::new(cx.executor());
        fs.insert_tree(
            path!("/project"),
            json!({
                ".git": {},
                "foo.txt": "FOO\n",
            }),
        )
        .await;
        let project = Project::test(fs.clone(), [path!("/project").as_ref()], cx).await;
        let (workspace, cx) =
            cx.add_window_view(|window, cx| Workspace::test_new(project.clone(), window, cx));
        let diff = cx.new_window_entity(|window, cx| {
            ProjectDiff::new(project.clone(), workspace, window, cx)
        });
        cx.run_until_parked();

        fs.set_head_for_repo(
            path!("/project/.git").as_ref(),
            &[("foo.txt".into(), "foo\n".into())],
            "deadbeef",
        );
        fs.set_index_for_repo(
            path!("/project/.git").as_ref(),
            &[("foo.txt".into(), "foo\n".into())],
        );
        cx.run_until_parked();

        let editor = diff.read_with(cx, |diff, _| diff.editor.clone());
        assert_state_with_diff(
            &editor,
            cx,
            &"
                - foo
                + ˇFOO
            "
            .unindent(),
        );

        editor.update_in(cx, |editor, window, cx| {
            editor.git_restore(&Default::default(), window, cx);
        });
        cx.run_until_parked();

        assert_state_with_diff(&editor, cx, &"ˇ".unindent());

        let text = String::from_utf8(fs.read_file_sync("/project/foo.txt").unwrap()).unwrap();
        assert_eq!(text, "foo\n");
    }

    #[gpui::test]
    async fn test_scroll_to_beginning_with_deletion(cx: &mut TestAppContext) {
        init_test(cx);

        let fs = FakeFs::new(cx.executor());
        fs.insert_tree(
            path!("/project"),
            json!({
                ".git": {},
                "bar": "BAR\n",
                "foo": "FOO\n",
            }),
        )
        .await;
        let project = Project::test(fs.clone(), [path!("/project").as_ref()], cx).await;
        let (workspace, cx) =
            cx.add_window_view(|window, cx| Workspace::test_new(project.clone(), window, cx));
        let diff = cx.new_window_entity(|window, cx| {
            ProjectDiff::new(project.clone(), workspace, window, cx)
        });
        cx.run_until_parked();

        fs.set_head_and_index_for_repo(
            path!("/project/.git").as_ref(),
            &[
                ("bar".into(), "bar\n".into()),
                ("foo".into(), "foo\n".into()),
            ],
        );
        cx.run_until_parked();

        let editor = cx.update_window_entity(&diff, |diff, window, cx| {
            diff.move_to_path(
                PathKey::namespaced(TRACKED_NAMESPACE, Path::new("foo").into()),
                window,
                cx,
            );
            diff.editor.clone()
        });
        assert_state_with_diff(
            &editor,
            cx,
            &"
                - bar
                + BAR

                - ˇfoo
                + FOO
            "
            .unindent(),
        );

        let editor = cx.update_window_entity(&diff, |diff, window, cx| {
            diff.move_to_path(
                PathKey::namespaced(TRACKED_NAMESPACE, Path::new("bar").into()),
                window,
                cx,
            );
            diff.editor.clone()
        });
        assert_state_with_diff(
            &editor,
            cx,
            &"
                - ˇbar
                + BAR

                - foo
                + FOO
            "
            .unindent(),
        );
    }

    #[gpui::test]
    async fn test_hunks_after_restore_then_modify(cx: &mut TestAppContext) {
        init_test(cx);

        let fs = FakeFs::new(cx.executor());
        fs.insert_tree(
            path!("/project"),
            json!({
                ".git": {},
                "foo": "modified\n",
            }),
        )
        .await;
        let project = Project::test(fs.clone(), [path!("/project").as_ref()], cx).await;
        let (workspace, cx) =
            cx.add_window_view(|window, cx| Workspace::test_new(project.clone(), window, cx));
        let buffer = project
            .update(cx, |project, cx| {
                project.open_local_buffer(path!("/project/foo"), cx)
            })
            .await
            .unwrap();
        let buffer_editor = cx.new_window_entity(|window, cx| {
            Editor::for_buffer(buffer, Some(project.clone()), window, cx)
        });
        let diff = cx.new_window_entity(|window, cx| {
            ProjectDiff::new(project.clone(), workspace, window, cx)
        });
        cx.run_until_parked();

        fs.set_head_for_repo(
            path!("/project/.git").as_ref(),
            &[("foo".into(), "original\n".into())],
            "deadbeef",
        );
        cx.run_until_parked();

        let diff_editor = diff.read_with(cx, |diff, _| diff.editor.clone());

        assert_state_with_diff(
            &diff_editor,
            cx,
            &"
                - original
                + ˇmodified
            "
            .unindent(),
        );

        let prev_buffer_hunks =
            cx.update_window_entity(&buffer_editor, |buffer_editor, window, cx| {
                let snapshot = buffer_editor.snapshot(window, cx);
                let snapshot = &snapshot.buffer_snapshot;
                let prev_buffer_hunks = buffer_editor
                    .diff_hunks_in_ranges(&[editor::Anchor::min()..editor::Anchor::max()], snapshot)
                    .collect::<Vec<_>>();
                buffer_editor.git_restore(&Default::default(), window, cx);
                prev_buffer_hunks
            });
        assert_eq!(prev_buffer_hunks.len(), 1);
        cx.run_until_parked();

        let new_buffer_hunks =
            cx.update_window_entity(&buffer_editor, |buffer_editor, window, cx| {
                let snapshot = buffer_editor.snapshot(window, cx);
                let snapshot = &snapshot.buffer_snapshot;
                buffer_editor
                    .diff_hunks_in_ranges(&[editor::Anchor::min()..editor::Anchor::max()], snapshot)
                    .collect::<Vec<_>>()
            });
        assert_eq!(new_buffer_hunks.as_slice(), &[]);

        cx.update_window_entity(&buffer_editor, |buffer_editor, window, cx| {
            buffer_editor.set_text("different\n", window, cx);
            buffer_editor.save(
                SaveOptions {
                    format: false,
                    autosave: false,
                },
                project.clone(),
                window,
                cx,
            )
        })
        .await
        .unwrap();

        cx.run_until_parked();

        cx.update_window_entity(&buffer_editor, |buffer_editor, window, cx| {
            buffer_editor.expand_all_diff_hunks(&Default::default(), window, cx);
        });

        assert_state_with_diff(
            &buffer_editor,
            cx,
            &"
                - original
                + different
                  ˇ"
            .unindent(),
        );

        assert_state_with_diff(
            &diff_editor,
            cx,
            &"
                - original
                + different
                  ˇ"
            .unindent(),
        );
    }

    use crate::{
        conflict_view::resolve_conflict,
        project_diff::{self, ProjectDiff},
    };

    #[gpui::test]
    async fn test_go_to_prev_hunk_multibuffer(cx: &mut TestAppContext) {
        init_test(cx);

        let fs = FakeFs::new(cx.executor());
        fs.insert_tree(
            "/a",
            json!({
                ".git": {},
                "a.txt": "created\n",
                "b.txt": "really changed\n",
                "c.txt": "unchanged\n"
            }),
        )
        .await;

        fs.set_git_content_for_repo(
            Path::new("/a/.git"),
            &[
                ("b.txt".into(), "before\n".to_string(), None),
                ("c.txt".into(), "unchanged\n".to_string(), None),
                ("d.txt".into(), "deleted\n".to_string(), None),
            ],
        );

        let project = Project::test(fs, [Path::new("/a")], cx).await;
        let (workspace, cx) =
            cx.add_window_view(|window, cx| Workspace::test_new(project, window, cx));

        cx.run_until_parked();

        cx.focus(&workspace);
        cx.update(|window, cx| {
            window.dispatch_action(project_diff::Diff.boxed_clone(), cx);
        });

        cx.run_until_parked();

        let item = workspace.update(cx, |workspace, cx| {
            workspace.active_item_as::<ProjectDiff>(cx).unwrap()
        });
        cx.focus(&item);
        let editor = item.read_with(cx, |item, _| item.editor.clone());

        let mut cx = EditorTestContext::for_editor_in(editor, cx).await;

        cx.assert_excerpts_with_selections(indoc!(
            "
            [EXCERPT]
            before
            really changed
            [EXCERPT]
            [FOLDED]
            [EXCERPT]
            ˇcreated
        "
        ));

        cx.dispatch_action(editor::actions::GoToPreviousHunk);

        cx.assert_excerpts_with_selections(indoc!(
            "
            [EXCERPT]
            before
            really changed
            [EXCERPT]
            ˇ[FOLDED]
            [EXCERPT]
            created
        "
        ));

        cx.dispatch_action(editor::actions::GoToPreviousHunk);

        cx.assert_excerpts_with_selections(indoc!(
            "
            [EXCERPT]
            ˇbefore
            really changed
            [EXCERPT]
            [FOLDED]
            [EXCERPT]
            created
        "
        ));
    }

    #[gpui::test]
    async fn test_excerpts_splitting_after_restoring_the_middle_excerpt(cx: &mut TestAppContext) {
        init_test(cx);

        let git_contents = indoc! {r#"
            #[rustfmt::skip]
            fn main() {
                let x = 0.0; // this line will be removed
                // 1
                // 2
                // 3
                let y = 0.0; // this line will be removed
                // 1
                // 2
                // 3
                let arr = [
                    0.0, // this line will be removed
                    0.0, // this line will be removed
                    0.0, // this line will be removed
                    0.0, // this line will be removed
                ];
            }
        "#};
        let buffer_contents = indoc! {"
            #[rustfmt::skip]
            fn main() {
                // 1
                // 2
                // 3
                // 1
                // 2
                // 3
                let arr = [
                ];
            }
        "};

        let fs = FakeFs::new(cx.executor());
        fs.insert_tree(
            "/a",
            json!({
                ".git": {},
                "main.rs": buffer_contents,
            }),
        )
        .await;

        fs.set_git_content_for_repo(
            Path::new("/a/.git"),
            &[("main.rs".into(), git_contents.to_owned(), None)],
        );

        let project = Project::test(fs, [Path::new("/a")], cx).await;
        let (workspace, cx) =
            cx.add_window_view(|window, cx| Workspace::test_new(project, window, cx));

        cx.run_until_parked();

        cx.focus(&workspace);
        cx.update(|window, cx| {
            window.dispatch_action(project_diff::Diff.boxed_clone(), cx);
        });

        cx.run_until_parked();

        let item = workspace.update(cx, |workspace, cx| {
            workspace.active_item_as::<ProjectDiff>(cx).unwrap()
        });
        cx.focus(&item);
        let editor = item.read_with(cx, |item, _| item.editor.clone());

        let mut cx = EditorTestContext::for_editor_in(editor, cx).await;

        cx.assert_excerpts_with_selections(&format!("[EXCERPT]\nˇ{git_contents}"));

        cx.dispatch_action(editor::actions::GoToHunk);
        cx.dispatch_action(editor::actions::GoToHunk);
        cx.dispatch_action(git::Restore);
        cx.dispatch_action(editor::actions::MoveToBeginning);

        cx.assert_excerpts_with_selections(&format!("[EXCERPT]\nˇ{git_contents}"));
    }

    #[gpui::test]
    async fn test_saving_resolved_conflicts(cx: &mut TestAppContext) {
        init_test(cx);

        let fs = FakeFs::new(cx.executor());
        fs.insert_tree(
            path!("/project"),
            json!({
                ".git": {},
                "foo": "<<<<<<< x\nours\n=======\ntheirs\n>>>>>>> y\n",
            }),
        )
        .await;
        fs.set_status_for_repo(
            Path::new(path!("/project/.git")),
            &[(
                Path::new("foo"),
                UnmergedStatus {
                    first_head: UnmergedStatusCode::Updated,
                    second_head: UnmergedStatusCode::Updated,
                }
                .into(),
            )],
        );
        let project = Project::test(fs.clone(), [path!("/project").as_ref()], cx).await;
        let (workspace, cx) =
            cx.add_window_view(|window, cx| Workspace::test_new(project.clone(), window, cx));
        let diff = cx.new_window_entity(|window, cx| {
            ProjectDiff::new(project.clone(), workspace, window, cx)
        });
        cx.run_until_parked();

        cx.update(|window, cx| {
            let editor = diff.read(cx).editor.clone();
            let excerpt_ids = editor.read(cx).buffer().read(cx).excerpt_ids();
            assert_eq!(excerpt_ids.len(), 1);
            let excerpt_id = excerpt_ids[0];
            let buffer = editor
                .read(cx)
                .buffer()
                .read(cx)
                .all_buffers()
                .into_iter()
                .next()
                .unwrap();
            let buffer_id = buffer.read(cx).remote_id();
            let conflict_set = diff
                .read(cx)
                .editor
                .read(cx)
                .addon::<ConflictAddon>()
                .unwrap()
                .conflict_set(buffer_id)
                .unwrap();
            assert!(conflict_set.read(cx).has_conflict);
            let snapshot = conflict_set.read(cx).snapshot();
            assert_eq!(snapshot.conflicts.len(), 1);

            let ours_range = snapshot.conflicts[0].ours.clone();

            resolve_conflict(
                editor.downgrade(),
                excerpt_id,
                snapshot.conflicts[0].clone(),
                vec![ours_range],
                window,
                cx,
            )
        })
        .await;

        let contents = fs.read_file_sync(path!("/project/foo")).unwrap();
        let contents = String::from_utf8(contents).unwrap();
        assert_eq!(contents, "ours\n");
    }
}