From 9918a9d06b7bc3ad80d89b99261588cb8f53883f Mon Sep 17 00:00:00 2001
From: Inomdzhon Mirdzhamolov <i.mirdzhamolov@vk.team>
Date: Fri, 26 Jan 2024 08:41:51 +0300
Subject: [PATCH] fix(Cell): patch client height of html (see `draggable` mode)
 (#6456)

---
 packages/vkui/src/lib/dom.test.ts | 27 +++++++++++++++++++++++----
 packages/vkui/src/lib/dom.tsx     | 15 +++++++++++++++
 2 files changed, 38 insertions(+), 4 deletions(-)

diff --git a/packages/vkui/src/lib/dom.test.ts b/packages/vkui/src/lib/dom.test.ts
index 3d0c06f062..27346c618b 100644
--- a/packages/vkui/src/lib/dom.test.ts
+++ b/packages/vkui/src/lib/dom.test.ts
@@ -28,7 +28,7 @@ const getChildElOfParentWithTransformedStyle = (
   return { parentEl, parentElRect, childEl, childElRect };
 };
 
-describe('getTransformedParentCoords', () => {
+describe(getTransformedParentCoords, () => {
   const transformDefault = TRANSFORM_DEFAULT_VALUES.map((v) => ({ transform: v }));
   const willChangeDefault = WILL_CHANGE_DEFAULT_VALUES.map((v) => ({ willChange: v }));
 
@@ -68,13 +68,16 @@ describe('getTransformedParentCoords', () => {
   });
 });
 
-describe('getScrollRect', () => {
+describe(getScrollRect, () => {
   test.each([
     { scrollTop: 0, viewportHeight: 100 },
     { scrollTop: 10, viewportHeight: 100 },
     { scrollTop: 0, viewportHeight: 768 },
     { scrollTop: 10, viewportHeight: 768 },
   ])('[window] should return correct y edges for %j', ({ scrollTop, viewportHeight }) => {
+    jest
+      .spyOn(document.documentElement, 'clientHeight', 'get')
+      .mockImplementation(() => viewportHeight);
     const rect = new DOMRect(0, scrollTop > 0 ? -1 * scrollTop : scrollTop, 1280, viewportHeight);
     window.scrollY = document.documentElement.scrollTop = scrollTop;
     document.documentElement.getBoundingClientRect = jest.fn(() => rect);
@@ -99,7 +102,7 @@ describe('getScrollRect', () => {
   });
 });
 
-describe('getScrollHeight', () => {
+describe(getScrollHeight, () => {
   const getScrollHeightMock = () => 1000;
   const scrollEl = document.createElement('div');
   beforeEach(() => {
@@ -116,7 +119,7 @@ describe('getScrollHeight', () => {
   });
 });
 
-describe('getBoundingClientRect', () => {
+describe(getBoundingClientRect, () => {
   it('should return rect without offset', () => {
     const { childEl, childElRect } = getChildElOfParentWithTransformedStyle();
     expect(getBoundingClientRect(childEl)).toEqual(childElRect);
@@ -144,6 +147,22 @@ describe('getBoundingClientRect', () => {
       }),
     );
   });
+
+  it('should apply `clientHeight` to `height` of `getBoundingClientRect()` if element is HTML', () => {
+    const HTML_CLIENT_HEIGHT = 768;
+    const HTML_SCROLL_HEIGHT = 2000;
+
+    jest
+      .spyOn(document.documentElement, 'clientHeight', 'get')
+      .mockImplementation(() => HTML_CLIENT_HEIGHT);
+
+    // Симулируем, что на странице не указан `html, body { height: 100% }` (или `height: 100vh`).
+    document.documentElement.getBoundingClientRect = jest.fn(
+      () => new DOMRect(0, 0, 1280, HTML_SCROLL_HEIGHT),
+    );
+
+    expect(getBoundingClientRect(document.documentElement).height).toBe(HTML_CLIENT_HEIGHT);
+  });
 });
 
 describe(getDocumentBody, () => {
diff --git a/packages/vkui/src/lib/dom.tsx b/packages/vkui/src/lib/dom.tsx
index b0785e35c9..96ff86efcf 100644
--- a/packages/vkui/src/lib/dom.tsx
+++ b/packages/vkui/src/lib/dom.tsx
@@ -58,6 +58,12 @@ export const isBody = (
   return node !== null && node !== undefined && 'tagName' in node && node.tagName === 'BODY';
 };
 
+export const isDocumentElement = (
+  node: Element | Window | VisualViewport | undefined | null,
+): node is HTMLHtmlElement => {
+  return node !== null && node !== undefined && 'tagName' in node && node.tagName === 'HTML';
+};
+
 export function withDOM<Props>(
   Component: React.ComponentType<Props & DOMProps>,
 ): React.ComponentType<Props> {
@@ -98,6 +104,15 @@ export const getBoundingClientRect = (node: Element | Window, isFixedStrategy =
   const element = isWindow(node) ? node.document.documentElement : node;
   const clientRect = element.getBoundingClientRect();
 
+  if (isDocumentElement(element)) {
+    /**
+     * Если на странице не используется `html, body { height: 100% }` (или `height: 100vh`), то
+     * `height`, полученный из `document.documentElement.getBoundingClientRect()`, будет возвращать
+     * `scrollHeight`, а не `clientHeight`. Поэтому перебиваем `height` на `clientHeight`.
+     */
+    clientRect.height = element.clientHeight;
+  }
+
   let offsetX = 0;
   let offsetY = 0;
   if (isFixedStrategy) {