Files · Explorer: a folder as a list, tiles or columns, with one path and one order

FileExplorer shows the folder at the end of a path three ways: the
directory listing, a grid of tiles, or a column per folder along the
path with the next folder lit. Its name, its count and a switch of views
sit above one path bar that climbs. A folder opens in place; a file goes
to the host, which lists each folder it goes to. A pick in an earlier
column closes the columns past it, and a new deepest column scrolls into
view. The directory listing takes its pick from its owner and reports
it, so the pick carries across views; its path bar and its first order
are shared. The gallery walks a small file system and shows the tree,
the context menu, renaming in place and a drop zone in use.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

src/files/tests/mod.rs

@@ -0,0 +1,188 @@
+use gpui::{
+    Context, Entity, IntoElement, KeyBinding, KeyUpEvent, Keystroke, Modifiers, ParentElement,
+    Render, SharedString, Styled, TestAppContext, VisualTestContext, Window, div, point, px,
+};
+use jiff::{Timestamp, ToSpan};
+
+use super::{FileGrid, item::detail};
+use crate::{lists::DirEntry, primitives::FocusNext, theme::Theme};
+
+mod explorer;
+
+pub(super) fn setup(cx: &mut TestAppContext) {
+    cx.update(|cx| {
+        Theme::init(cx);
+        Theme::update(cx, |theme| theme.reduced_motion = true);
+        cx.bind_keys([KeyBinding::new("tab", FocusNext, None)]);
+    });
+}
+
+pub(super) fn settle(cx: &mut VisualTestContext) {
+    for _ in 0..3 {
+        cx.run_until_parked();
+        cx.update(|window, _| window.refresh());
+    }
+    cx.run_until_parked();
+}
+
+pub(super) fn press(key: &str, cx: &mut VisualTestContext) {
+    cx.simulate_keystrokes(key);
+    settle(cx);
+    cx.simulate_event(KeyUpEvent {
+        keystroke: Keystroke::parse(key).expect("a key"),
+    });
+    settle(cx);
+}
+
+pub(super) fn then() -> Timestamp {
+    Timestamp::from_second(1_700_000_000).expect("a time")
+}
+
+#[test]
+fn a_row_says_a_files_size_and_a_folders_kind_with_when_each_changed() {
+    let now = then() + 2.hours();
+    assert_eq!(
+        detail(&DirEntry::file("a.txt", 2_400, then()), now),
+        "2.4 KB · 2 hours ago"
+    );
+    assert_eq!(
+        detail(&DirEntry::folder("Docs", then()), now),
+        "Folder · 2 hours ago"
+    );
+}
+
+/// Seven files in a grid three tiles across, and what it picked and opened.
+struct Tiled {
+    selected: Option<SharedString>,
+    picked: Vec<SharedString>,
+    opened: Vec<SharedString>,
+}
+
+impl Render for Tiled {
+    fn render(&mut self, _: &mut Window, cx: &mut Context<Self>) -> impl IntoElement {
+        let (pick, open) = (cx.entity(), cx.entity());
+        let names = ["a", "b", "c", "d", "e", "f", "g"];
+        let grid = FileGrid::new("grid", names.map(|name| DirEntry::file(name, 10, then())))
+            .on_select(move |name, _, cx| pick.update(cx, |view, _| view.picked.push(name.clone())))
+            .on_open(move |entry, _, cx| {
+                open.update(cx, |view, _| view.opened.push(entry.name().clone()))
+            });
+        let grid = match self.selected.clone() {
+            Some(name) => grid.selected(name),
+            None => grid,
+        };
+        div().w(px(320.0)).child(grid)
+    }
+}
+
+fn tiled<'a>(
+    selected: Option<&'static str>,
+    cx: &'a mut TestAppContext,
+) -> (Entity<Tiled>, &'a mut VisualTestContext) {
+    setup(cx);
+    let selected = selected.map(|name| SharedString::from(name.to_string()));
+    let (view, cx) = cx.add_window_view(move |_, _| Tiled {
+        selected,
+        picked: Vec::new(),
+        opened: Vec::new(),
+    });
+    cx.update(|window, _| window.activate_window());
+    settle(cx);
+    (view, cx)
+}
+
+fn heard(
+    view: &Entity<Tiled>,
+    cx: &mut VisualTestContext,
+) -> (Vec<SharedString>, Vec<SharedString>) {
+    view.read_with(cx, |view, _| (view.picked.clone(), view.opened.clone()))
+}
+
+#[gpui::test]
+fn the_arrows_move_by_tile_and_by_row_and_enter_opens(cx: &mut TestAppContext) {
+    let (view, cx) = tiled(None, cx);
+    cx.update(|window, _| window.focus_next());
+    for key in ["right", "right", "down", "down", "cmd-left"] {
+        press(key, cx);
+    }
+    press("enter", cx);
+    let (picked, opened) = heard(&view, cx);
+    assert_eq!(picked, ["a", "b", "e", "g"], "a command key passes");
+    assert_eq!(opened, ["g"]);
+}
+
+#[gpui::test]
+fn the_keys_start_from_the_tile_picked(cx: &mut TestAppContext) {
+    let (view, cx) = tiled(Some("c"), cx);
+    cx.update(|window, _| window.focus_next());
+    press("down", cx);
+    assert_eq!(heard(&view, cx).0, ["f"]);
+}
+
+#[gpui::test]
+fn a_press_picks_a_tile_and_a_double_press_opens_it(cx: &mut TestAppContext) {
+    let (view, cx) = tiled(None, cx);
+    let grid = cx.debug_bounds("file-grid").expect("the grid draws");
+    let first = grid.origin + point(px(12.0), px(8.0));
+    cx.simulate_click(first, Modifiers::none());
+    settle(cx);
+    assert_eq!(heard(&view, cx), (vec!["a".into()], vec![]));
+    cx.simulate_event(gpui::MouseDownEvent {
+        button: gpui::MouseButton::Left,
+        position: first,
+        modifiers: Modifiers::none(),
+        click_count: 2,
+        first_mouse: false,
+    });
+    cx.simulate_event(gpui::MouseUpEvent {
+        button: gpui::MouseButton::Left,
+        position: first,
+        modifiers: Modifiers::none(),
+        click_count: 2,
+    });
+    settle(cx);
+    assert_eq!(heard(&view, cx).1, ["a"]);
+}
+
+#[test]
+#[should_panic(expected = "a twice")]
+fn a_name_is_listed_once() {
+    let _ = FileGrid::new(
+        "grid",
+        ["a", "a"].map(|name| DirEntry::file(name, 1, then())),
+    );
+}
+
+#[test]
+#[should_panic(expected = "no entry z")]
+fn the_pick_is_one_of_the_entries() {
+    let _ = FileGrid::new("grid", [DirEntry::file("a", 1, then())]).selected("z");
+}
+
+/// One tile whose name runs long.
+struct Named;
+
+impl Render for Named {
+    fn render(&mut self, _: &mut Window, _: &mut Context<Self>) -> impl IntoElement {
+        let name = "A very long file name that keeps going past two whole lines.pdf";
+        div()
+            .w(px(280.0))
+            .child(FileGrid::new("grid", [DirEntry::file(name, 10, then())]))
+    }
+}
+
+#[gpui::test]
+fn a_long_name_takes_one_line_inside_its_tile(cx: &mut TestAppContext) {
+    setup(cx);
+    let (_, cx) = cx.add_window_view(|_, _| Named);
+    settle(cx);
+    let (name, grid) = (
+        cx.debug_bounds("file-name 0").expect("the name draws"),
+        cx.debug_bounds("file-grid").expect("the grid draws"),
+    );
+    assert!(name.size.height < px(24.0), "one line: {name:?}");
+    assert!(
+        name.left() >= grid.left() && name.right() <= grid.right(),
+        "{name:?} in {grid:?}"
+    );
+}