add multiline support to input

crates/core/tests/input.rs

@@ -4,7 +4,8 @@ use gpui::{
     TestAppContext, VisualTestContext, Window, div, point, px,
 };
 use gpui_native_core::input::{
-    INPUT_CONTEXT, Input, InputBindings, InputState, InputStateEvent, Submit, bind_input_keys,
+    INPUT_CONTEXT, Input, InputBindings, InputState, InputStateEvent, Submit, SubmitOn,
+    bind_input_keys,
 };
 use gpui_native_theme::Theme;
 use std::cell::RefCell;
@@ -599,6 +600,34 @@ fn password_window(initial: &str) -> (TestAppContext, Entity<InputState>, Visual
     (cx, state, visual)
 }
 
+fn multiline_window(initial: &str) -> (TestAppContext, Entity<InputState>, VisualTestContext) {
+    let mut cx = TestAppContext::single();
+    cx.update(|cx| {
+        Theme::init(cx);
+        bind_input_keys(cx, InputBindings::default());
+    });
+    let state = cx.update(InputState::new);
+    cx.update(|cx| {
+        state.update(cx, |state, cx| state.set_multiline(true, cx));
+    });
+    let state_for_window = state.clone();
+    let window = cx.add_window(move |_, _| Harness {
+        state: state_for_window,
+        disabled: false,
+    });
+    let mut visual = VisualTestContext::from_window(window.into(), &cx);
+    if !initial.is_empty() {
+        // Seeding after the mode flips so newlines survive the sanitizer.
+        visual.update(|window, cx| {
+            state.update(cx, |state, cx| state.set_value(initial, window, cx));
+        });
+    }
+    visual.update(|window, cx| {
+        window.draw(cx).clear(cx);
+    });
+    (cx, state, visual)
+}
+
 #[test]
 fn password_fields_keep_the_real_buffer_while_masked() {
     let (cx, state, mut visual) = password_window("");
@@ -733,3 +762,147 @@ fn the_reveal_toggle_flips_masking() {
     let revealed = cx.update(|cx| state.read(cx).is_revealed());
     assert!(!revealed, "the toggle should mask the field again");
 }
+
+#[test]
+fn the_caret_can_rest_on_a_line_break() {
+    let (cx, state, mut visual) = multiline_window("ab\ncdef");
+    focus(&mut visual, &state);
+
+    // Five lefts land the caret on the line break at the end of row 1 —
+    // an offset between the two rows — and painting must not panic there.
+    visual.simulate_keystrokes("left left left left left");
+    visual.update(|window, cx| {
+        window.draw(cx).clear(cx);
+    });
+    visual.simulate_keystrokes("x");
+    assert_eq!(value(&cx, &state), "abx\ncdef");
+}
+
+#[test]
+fn multiline_fields_keep_newlines() {
+    let (cx, state, mut visual) = multiline_window("");
+    focus(&mut visual, &state);
+    visual.update(|window, cx| {
+        state.update(cx, |state, cx| state.set_value("a\nb", window, cx));
+    });
+    assert_eq!(value(&cx, &state), "a\nb");
+
+    // Paste keeps line breaks too.
+    cx.update(|cx| {
+        cx.write_to_clipboard(gpui::ClipboardItem::new_string("x\ny".to_string()));
+    });
+    visual.simulate_keystrokes("cmd-v");
+    assert_eq!(value(&cx, &state), "a\nbx\ny");
+}
+
+#[test]
+fn enter_inserts_a_newline_and_modifier_enter_submits() {
+    let (mut cx, state, mut visual) = multiline_window("");
+    let (sink, _subscription) = record_events(&mut cx, &state);
+    focus(&mut visual, &state);
+
+    visual.simulate_keystrokes("a b");
+    visual.simulate_keystrokes("enter");
+    assert_eq!(value(&cx, &state), "ab\n");
+    assert_eq!(count(&sink, &InputStateEvent::Submitted), 0);
+
+    visual.simulate_keystrokes("cmd-enter");
+    assert_eq!(count(&sink, &InputStateEvent::Submitted), 1);
+    assert_eq!(value(&cx, &state), "ab\n");
+}
+
+#[test]
+fn submit_on_enter_swaps_the_keys() {
+    let (mut cx, state, mut visual) = multiline_window("");
+    let (sink, _subscription) = record_events(&mut cx, &state);
+    visual.update(|_, cx| {
+        state.update(cx, |state, cx| state.set_submit_on(SubmitOn::Enter, cx));
+    });
+    focus(&mut visual, &state);
+
+    // Enter submits; Shift + Enter breaks the line.
+    visual.simulate_keystrokes("enter");
+    assert_eq!(count(&sink, &InputStateEvent::Submitted), 1);
+    assert_eq!(value(&cx, &state), "");
+    visual.simulate_keystrokes("shift-enter");
+    assert_eq!(value(&cx, &state), "\n");
+}
+
+#[test]
+fn up_and_down_move_between_rows() {
+    let (cx, state, mut visual) = multiline_window("ab\ncdef");
+    focus(&mut visual, &state);
+
+    // From the end of row 1, shift-up reaches the end of the shorter row 0.
+    visual.simulate_keystrokes("shift-up");
+    visual.simulate_keystrokes("backspace");
+    assert_eq!(value(&cx, &state), "ab");
+
+    // From the start of row 0, shift-down reaches the start of row 1.
+    visual.update(|window, cx| {
+        state.update(cx, |state, cx| state.set_value("ab\ncdef", window, cx));
+    });
+    visual.simulate_keystrokes("home");
+    visual.simulate_keystrokes("shift-down");
+    visual.simulate_keystrokes("backspace");
+    assert_eq!(value(&cx, &state), "cdef");
+}
+
+#[test]
+fn single_line_fields_ignore_up_and_down() {
+    let (cx, state, mut visual) = input_window("ab", false);
+    focus(&mut visual, &state);
+    visual.simulate_keystrokes("up down");
+    visual.simulate_keystrokes("x");
+    assert_eq!(value(&cx, &state), "abx");
+}
+
+#[test]
+fn triple_click_selects_the_clicked_row() {
+    let (cx, state, mut visual) = multiline_window("ab\ncdef");
+    focus(&mut visual, &state);
+
+    // The second row's center sits one line height below the first's.
+    let at = point(px(30.), px(44.));
+    visual.simulate_event(MouseDownEvent {
+        position: at,
+        modifiers: Modifiers::default(),
+        button: MouseButton::Left,
+        click_count: 3,
+        first_mouse: false,
+    });
+    visual.simulate_event(MouseUpEvent {
+        position: at,
+        modifiers: Modifiers::default(),
+        button: MouseButton::Left,
+        click_count: 3,
+    });
+    visual.simulate_keystrokes("cmd-c");
+    let clipboard = cx.update(|cx| {
+        cx.read_from_clipboard()
+            .and_then(|item| item.text())
+            .unwrap_or_default()
+    });
+    assert_eq!(clipboard, "cdef");
+}
+
+#[test]
+fn vertical_scroll_keeps_the_caret_in_view() {
+    let (_cx, state, mut visual) = multiline_window("l1\nl2\nl3\nl4\nl5\nl6");
+    focus(&mut visual, &state);
+    visual.update(|window, cx| {
+        window.draw(cx).clear(cx);
+    });
+
+    // The field shows four of the six rows and the caret ends on the last,
+    // so the view scrolls down and row 1 sits above the field's top.
+    let first_row_top = visual
+        .update(|window, cx| {
+            state.update(cx, |state, cx| {
+                state.bounds_for_range(0..1, Default::default(), window, cx)
+            })
+        })
+        .map(|bounds| bounds.top())
+        .unwrap_or_default();
+    assert!(first_row_top < px(0.), "first row top: {first_row_top:?}");
+}