fix: New comments are measured incorrectly (#8838)

* fix: New comments are measured incorrectly

* Remove defaultRect so we can always return a DOMRect

app/components/Fade.tsx

@@ -2,6 +2,11 @@ import React from "react";
 import styled from "styled-components";
 import { fadeIn } from "~/styles/animations";
 
+/**
+ * Fade in animation for a component.
+ *
+ * @param timing - The duration of the fade in animation, default is 250ms.
+ */
 const Fade = styled.span<{ timing?: number | string }>`
   animation: ${fadeIn} ${(props) => props.timing || "250ms"} ease-in-out;
 `;
@@ -17,7 +22,6 @@ type Props = {
  */
 export const ConditionalFade = ({ animate, children }: Props) => {
   const [isAnimated] = React.useState(animate);
-
   return isAnimated ? <Fade>{children}</Fade> : <>{children}</>;
 };
 

app/scenes/Document/components/CommentThread.tsx

@@ -16,6 +16,7 @@ import { useDocumentContext } from "~/components/DocumentContext";
 import Facepile from "~/components/Facepile";
 import Fade from "~/components/Fade";
 import { ResizingHeightContainer } from "~/components/ResizingHeightContainer";
+import useBoolean from "~/hooks/useBoolean";
 import { useLocationSidebarContext } from "~/hooks/useLocationSidebarContext";
 import useOnClickOutside from "~/hooks/useOnClickOutside";
 import usePersistedState from "~/hooks/usePersistedState";
@@ -63,7 +64,7 @@ function CommentThread({
   const history = useHistory();
   const location = useLocation();
   const sidebarContext = useLocationSidebarContext();
-  const [autoFocus, setAutoFocus] = React.useState(thread.isNew);
+  const [autoFocus, setAutoFocusOn, setAutoFocusOff] = useBoolean(thread.isNew);
 
   const can = usePolicy(document);
 
@@ -156,9 +157,9 @@ function CommentThread({
 
   React.useEffect(() => {
     if (!focused && autoFocus) {
-      setAutoFocus(false);
+      setAutoFocusOff();
     }
-  }, [focused, autoFocus]);
+  }, [focused, autoFocus, setAutoFocusOff]);
 
   React.useEffect(() => {
     if (focused) {
@@ -273,7 +274,7 @@ function CommentThread({
         )}
       </ResizingHeightContainer>
       {!focused && !recessed && !draft && canReply && (
-        <Reply onClick={() => setAutoFocus(true)}>{t("Reply")}…</Reply>
+        <Reply onClick={setAutoFocusOn}>{t("Reply")}…</Reply>
       )}
     </Thread>
   );

shared/hooks/useComponentSize.ts

@@ -1,16 +1,5 @@
 import { useState, useLayoutEffect } from "react";
 
-const defaultRect = {
-  top: 0,
-  left: 0,
-  bottom: 0,
-  right: 0,
-  x: 0,
-  y: 0,
-  width: 0,
-  height: 0,
-};
-
 /**
  * A hook that returns the size of an element or ref.
  *
@@ -19,19 +8,11 @@ const defaultRect = {
  */
 export function useComponentSize(
   input: HTMLElement | null | React.RefObject<HTMLElement | null>
-): DOMRect | typeof defaultRect {
+) {
   const element = input instanceof HTMLElement ? input : input?.current;
-  const [size, setSize] = useState(() => element?.getBoundingClientRect());
-
-  useLayoutEffect(() => {
-    const sizeObserver = new ResizeObserver(() => {
-      element?.dispatchEvent(new CustomEvent("resize"));
-    });
-    if (element) {
-      sizeObserver.observe(element);
-    }
-    return () => sizeObserver.disconnect();
-  }, [element]);
+  const [size, setSize] = useState<DOMRect | undefined>(
+    () => element?.getBoundingClientRect() || new DOMRect()
+  );
 
   useLayoutEffect(() => {
     const handleResize = () => {
@@ -55,6 +36,7 @@ export function useComponentSize(
     window.addEventListener("click", handleResize);
     window.addEventListener("resize", handleResize);
     element?.addEventListener("resize", handleResize);
+    handleResize();
 
     return () => {
       window.removeEventListener("click", handleResize);
@@ -63,5 +45,15 @@ export function useComponentSize(
     };
   });
 
-  return size ?? defaultRect;
+  useLayoutEffect(() => {
+    const sizeObserver = new ResizeObserver(() => {
+      element?.dispatchEvent(new CustomEvent("resize"));
+    });
+    if (element) {
+      sizeObserver.observe(element);
+    }
+    return () => sizeObserver.disconnect();
+  }, [element]);
+
+  return size ?? new DOMRect();
 }