Feat 427 initial scroll at window end

__tests__/__mocks__/createMockState.ts

@@ -111,6 +111,7 @@ export function createMockState(
             horizontal: false,
             initialContainerPoolRatio: 2,
             initialScroll: undefined,
+            initialScrollAtWindowEnd: false,
             itemsAreEqual: undefined,
             keyExtractor: (_: any, index: number) => `item_${index}`,
             maintainScrollAtEnd: undefined,

__tests__/components/ListComponentScrollView.web.test.tsx

@@ -12,6 +12,7 @@ const addEventListener = mock((type: string, listener: ScrollListener) => {
 const removeEventListener = mock((type: string) => {
     scrollListeners.delete(type);
 });
+const scrollToTarget = mock((_options?: ScrollToOptions) => {});
 const schedule = mock(() => true);
 const flush = mock(() => {});
 const cancel = mock(() => {});
@@ -37,6 +38,7 @@ function registerWebScrollMocks() {
     mock.module("../../src/components/webScrollUtils", () => ({
         clampOffset: (offset: number) => offset,
         getContentSize: () => ({ height: 0, width: 0 }),
+        getDocumentMaxOffset: () => 444,
         getElementDocumentPosition: () => ({ left: 0, top: 0 }),
         getLayoutMeasurement: () => ({ height: 0, width: 0 }),
         getLayoutRectangle: () => ({ height: 0, width: 0, x: 0, y: 0 }),
@@ -47,6 +49,7 @@ function registerWebScrollMocks() {
         resolveScrollEventTarget: () => ({
             addEventListener,
             removeEventListener,
+            scrollTo: scrollToTarget,
         }),
         resolveWindowScrollTarget: () => ({ left: 0, top: 0 }),
     }));
@@ -56,6 +59,7 @@ function resetMocks() {
     scrollListeners.clear();
     addEventListener.mockClear();
     removeEventListener.mockClear();
+    scrollToTarget.mockClear();
     schedule.mockClear();
     flush.mockClear();
     cancel.mockClear();
@@ -140,4 +144,39 @@ describe("ListComponentScrollView (web)", () => {
             });
         }
     });
+
+    it("scrolls the document to its end for initial window-end requests", async () => {
+        resetMocks();
+        const ref = { current: null as any };
+        const { ListComponentScrollView } = await import(
+            "../../src/components/ListComponentScrollView?web-scroll-window-end"
+        );
+        let renderer: TestRenderer.ReactTestRenderer | undefined;
+
+        try {
+            act(() => {
+                renderer = TestRenderer.create(
+                    <ListComponentScrollView
+                        initialScrollAtWindowEnd
+                        onLayout={() => {}}
+                        ref={ref as any}
+                        style={{}}
+                        useWindowScroll
+                    >
+                        <div />
+                    </ListComponentScrollView>,
+                );
+            });
+
+            act(() => {
+                ref.current.scrollTo({ animated: false, initialScrollAtWindowEnd: true, y: 120 });
+            });
+
+            expect(scrollToTarget).toHaveBeenCalledWith({ behavior: "auto", left: 0, top: 444 });
+        } finally {
+            act(() => {
+                renderer?.unmount();
+            });
+        }
+    });
 });

__tests__/core/bootstrapInitialScroll.test.ts

@@ -398,7 +398,8 @@ describe("bootstrapInitialScroll", () => {
         Platform.OS = "android";
 
         const data = Array.from({ length: 8 }, (_, index) => ({ id: `item-${index}` }));
-        const scrollToCalls: Array<{ animated: boolean; x: number; y: number }> = [];
+        const scrollToCalls: Array<{ animated: boolean; initialScrollAtWindowEnd?: boolean; x: number; y: number }> =
+            [];
         const ctx = createMockContext(
             {
                 totalSize: 800,
@@ -441,7 +442,12 @@ describe("bootstrapInitialScroll", () => {
                 refScroller: {
                     current: {
                         getScrollableNode: () => ({}),
-                        scrollTo: (params: { animated: boolean; x: number; y: number }) => scrollToCalls.push(params),
+                        scrollTo: (params: {
+                            animated: boolean;
+                            initialScrollAtWindowEnd?: boolean;
+                            x: number;
+                            y: number;
+                        }) => scrollToCalls.push(params),
                     },
                 } as StateContext["state"]["refScroller"],
                 scrollLength: 200,
@@ -457,7 +463,7 @@ describe("bootstrapInitialScroll", () => {
         evaluateBootstrapInitialScroll(ctx);
         evaluateBootstrapInitialScroll(ctx);
 
-        expect(scrollToCalls).toEqual([{ animated: false, x: 0, y: 500 }]);
+        expect(scrollToCalls).toEqual([{ animated: false, initialScrollAtWindowEnd: false, x: 0, y: 500 }]);
         expect(ctx.state.didFinishInitialScroll).toBe(false);
         expect(ctx.state.initialScroll).toMatchObject({
             contentOffset: 500,

__tests__/core/scrollTo.test.ts

@@ -126,6 +126,7 @@ describe("scrollTo", () => {
         expect(doScrollToSpy).toHaveBeenCalledWith(mockCtx, {
             animated: true,
             horizontal: false,
+            initialScrollAtWindowEnd: false,
             isInitialScroll: true,
             offset: 140,
         });
@@ -158,6 +159,7 @@ describe("scrollTo", () => {
         expect(doScrollToSpy).toHaveBeenCalledWith(mockCtx, {
             animated: false,
             horizontal: false,
+            initialScrollAtWindowEnd: false,
             isInitialScroll: true,
             offset: 0,
         });
@@ -169,4 +171,23 @@ describe("scrollTo", () => {
             targetOffset: 0,
         });
     });
+
+    it("passes initialScrollAtWindowEnd to forced initial scroll dispatches", () => {
+        mockCtx.state.props.initialScrollAtWindowEnd = true;
+
+        scrollTo(mockCtx, {
+            animated: false,
+            forceScroll: true,
+            isInitialScroll: true,
+            offset: 140,
+        });
+
+        expect(doScrollToSpy).toHaveBeenCalledWith(mockCtx, {
+            animated: false,
+            horizontal: false,
+            initialScrollAtWindowEnd: true,
+            isInitialScroll: true,
+            offset: 140,
+        });
+    });
 });