lazy scrolling fixes

src/textual/widget.py

@@ -2557,7 +2557,10 @@ def _lazily_scroll_end() -> None:
                 level=level,
             )
 
-        self.call_after_refresh(_lazily_scroll_end)
+        if immediate:
+            _lazily_scroll_end()
+        else:
+            self.call_after_refresh(_lazily_scroll_end)
 
     def scroll_left(
         self,
@@ -3215,18 +3218,35 @@ def scroll_visible(
         """
         parent = self.parent
         if isinstance(parent, Widget):
-            self.screen.scroll_to_widget(
-                self,
-                animate=animate,
-                speed=speed,
-                duration=duration,
-                top=top,
-                easing=easing,
-                force=force,
-                on_complete=on_complete,
-                level=level,
-                immediate=immediate,
-            )
+            if self.region:
+                self.screen.scroll_to_widget(
+                    self,
+                    animate=animate,
+                    speed=speed,
+                    duration=duration,
+                    top=top,
+                    easing=easing,
+                    force=force,
+                    on_complete=on_complete,
+                    level=level,
+                    immediate=immediate,
+                )
+            else:
+                # self.region is falsey which may indicate the widget hasn't been through a layout operation
+                # We can potentially make it do the right thing by postponing the scroll to after a refresh
+                self.call_after_refresh(
+                    self.screen.scroll_to_widget,
+                    self,
+                    animate=animate,
+                    speed=speed,
+                    duration=duration,
+                    top=top,
+                    easing=easing,
+                    force=force,
+                    on_complete=on_complete,
+                    level=level,
+                    immediate=immediate,
+                )
 
     def scroll_to_center(
         self,

src/textual/widgets/_collapsible.py

@@ -203,7 +203,7 @@ def _watch_collapsed(self, collapsed: bool) -> None:
             self.post_message(self.Collapsed(self))
         else:
             self.post_message(self.Expanded(self))
-            self.call_later(self.scroll_visible)
+            self.call_after_refresh(self.scroll_visible)
 
     def _update_collapsed(self, collapsed: bool) -> None:
         """Update children to match collapsed state."""

tests/snapshot_tests/snapshot_apps/dock_scroll_off_by_one.py

@@ -3,6 +3,7 @@
 
 
 class ScrollOffByOne(App):
+    AUTO_FOCUS = None
     HOVER_EFFECTS_SCROLL_PAUSE = 0.0
 
     def compose(self) -> ComposeResult:

tests/snapshot_tests/snapshot_apps/scroll_to.py

@@ -5,6 +5,7 @@
 class ScrollOffByOne(App):
     """Scroll to item 50."""
 
+    AUTO_FOCUS = None
     HOVER_EFFECTS_SCROLL_PAUSE = 0
 
     def compose(self) -> ComposeResult:

tests/snapshot_tests/test_snapshots.py

@@ -937,7 +937,6 @@ def test_dock_scroll_off_by_one(snap_compare):
     assert snap_compare(
         SNAPSHOT_APPS_DIR / "dock_scroll_off_by_one.py",
         terminal_size=(80, 25),
-        press=["_"],
     )
 
 
@@ -962,9 +961,7 @@ def compose(self) -> ComposeResult:
 
 def test_scroll_to(snap_compare):
     # https://github.com/Textualize/textual/issues/2525
-    assert snap_compare(
-        SNAPSHOT_APPS_DIR / "scroll_to.py", terminal_size=(80, 25), press=["_"]
-    )
+    assert snap_compare(SNAPSHOT_APPS_DIR / "scroll_to.py", terminal_size=(80, 25))
 
 
 def test_auto_fr(snap_compare):