fix(app): home page scroll target (#36664)

Co-authored-by: Jay V <air@live.ca> Co-authored-by: Brendan Allan <git@brendonovich.dev>
2026-07-16 15:21:42 +05:30
parent f6d31181f8
commit e9b6e427da
4 changed files with 302 additions and 143 deletions
@@ -72,4 +72,19 @@ describe("scrollTopFromThumbPointer", () => {
    expect(scrollTopFromThumbPointer({ ...input, pointer: 0 })).toBe(0)
    expect(scrollTopFromThumbPointer({ ...input, pointer: 1_000 })).toBe(5_400)
  })
+
+  test("uses scrollClientHeight when the thumb track differs from the viewport", () => {
+    const input = {
+      pointer: 400,
+      viewportTop: 100,
+      grabOffset: 0,
+      clientHeight: 400,
+      scrollClientHeight: 800,
+      scrollHeight: 8_000,
+      thumbHeight: 40,
+    }
+    // track usable = 400 - 16 - 40 = 344; thumbTop = 400 - 100 - 8 = 292
+    // maxScroll = 8000 - 800 = 7200 → 292/344 * 7200
+    expect(scrollTopFromThumbPointer(input)).toBeCloseTo((292 / 344) * 7200)
+  })
 })