refactor(webapp): replace render-time ref initialization (#4729)

## Summary

Replaces render-time ref initialization with lazy state for frozen form
defaults, the tooltip's virtual positioning element, and the side menu's
first-paint visuals. Editable alert fields now update immutable state
snapshots.

apps/webapp/app/components/errors/ConfigureErrorAlerts.tsx

@@ -103,13 +103,15 @@ export function ConfigureErrorAlerts({
     }
   }, [fetcher.state, fetcher.data, closeHref, navigate, toast]);
 
-  const emailFieldValues = useRef<string[]>(
+  const [emailDefaultValues] = useState<string[]>(() =>
     existingEmails.length > 0 ? [...existingEmails.map((e) => e.email), ""] : [""]
   );
+  const emailFieldValues = useRef([...emailDefaultValues]);
 
-  const webhookFieldValues = useRef<string[]>(
+  const [webhookDefaultValues] = useState<string[]>(() =>
     existingWebhooks.length > 0 ? [...existingWebhooks.map((w) => w.url), ""] : [""]
   );
+  const webhookFieldValues = useRef([...webhookDefaultValues]);
 
   const [form, fields] = useForm<z.infer<typeof ErrorAlertsFormSchema>>({
     id: "configure-error-alerts",
@@ -118,8 +120,8 @@ export function ConfigureErrorAlerts({
     },
     shouldRevalidate: "onSubmit",
     defaultValue: {
-      emails: emailFieldValues.current,
-      webhooks: webhookFieldValues.current,
+      emails: emailDefaultValues,
+      webhooks: webhookDefaultValues,
     },
   });
   const { emails, webhooks, slackChannel, slackIntegrationId } = fields;
@@ -170,7 +172,7 @@ export function ConfigureErrorAlerts({
                           emailFieldValues.current[index] = e.target.value;
                           if (
                             emailFields.length === emailFieldValues.current.length &&
-                            emailFieldValues.current.every((v) => v !== "")
+                            emailFieldValues.current.every((value) => value !== "")
                           ) {
                             form.insert({ name: emails.name });
                           }
@@ -324,7 +326,7 @@ export function ConfigureErrorAlerts({
                         webhookFieldValues.current[index] = e.target.value;
                         if (
                           webhookFields.length === webhookFieldValues.current.length &&
-                          webhookFieldValues.current.every((v) => v !== "")
+                          webhookFieldValues.current.every((value) => value !== "")
                         ) {
                           form.insert({ name: webhooks.name });
                         }

apps/webapp/app/components/navigation/SideMenu.tsx

@@ -366,25 +366,32 @@ export function SideMenu({
   const rafRef = useRef<number | null>(null);
   // Mirror of `isCollapsed` for the drag handlers (outside React's render cycle; no stale closures).
   const isCollapsedRef = useRef(isCollapsed);
+  // Freeze first-paint values so React never fights the imperative width writes after hydration.
+  const [initialVisual] = useState(() => {
+    const collapsed = user.dashboardPreferences.sideMenu?.isCollapsed ?? false;
+    const expandedWidth = clamp(
+      user.dashboardPreferences.sideMenu?.width ?? DEFAULT_WIDTH,
+      DEFAULT_WIDTH,
+      MAX_WIDTH
+    );
+    const width = collapsed ? COLLAPSED_WIDTH : expandedWidth;
+    const progress = collapsed ? 1 : 0;
+
+    return {
+      expandedWidth,
+      width,
+      progress,
+      style: {
+        width,
+        "--sm-collapse": String(progress),
+        "--sm-label-opacity": String(progressToLabelOpacity(progress)),
+      } as CSSProperties,
+    };
+  });
   // The last-committed expanded width; animation targets and re-expansion read from here.
-  const expandedWidthRef = useRef(
-    clamp(user.dashboardPreferences.sideMenu?.width ?? DEFAULT_WIDTH, DEFAULT_WIDTH, MAX_WIDTH)
-  );
-  // Frozen first-paint width; never changes, so React never fights the imperative width writes.
-  const initialWidthRef = useRef(
-    (user.dashboardPreferences.sideMenu?.isCollapsed ?? false)
-      ? COLLAPSED_WIDTH
-      : expandedWidthRef.current
-  );
-  const widthRef = useRef(initialWidthRef.current);
-  const progressRef = useRef((user.dashboardPreferences.sideMenu?.isCollapsed ?? false) ? 1 : 0);
-  // Frozen initial style (incl. CSS vars) so the SSR HTML has the right collapsed/expanded visuals
-  // (no pre-hydration flash). Stable identity, so React never rewrites it after writeVisual.
-  const initialStyleRef = useRef<CSSProperties>({
-    width: initialWidthRef.current,
-    "--sm-collapse": String(progressRef.current),
-    "--sm-label-opacity": String(progressToLabelOpacity(progressRef.current)),
-  } as CSSProperties);
+  const expandedWidthRef = useRef(initialVisual.expandedWidth);
+  const widthRef = useRef(initialVisual.width);
+  const progressRef = useRef(initialVisual.progress);
   // Removes an in-flight drag's window listeners (set on pointerdown; cleared on finish/unmount).
   const dragCleanupRef = useRef<(() => void) | null>(null);
 
@@ -1066,7 +1073,7 @@ export function SideMenu({
   return (
     <div
       ref={rootRef}
-      style={initialStyleRef.current}
+      style={initialVisual.style}
       className={cn(
         "relative h-full border-r bg-background-bright",
         // The accent is the loudest "you are not this user" tell, so "view as user" drops it too —

apps/webapp/app/components/primitives/TooltipPortal.tsx

@@ -4,7 +4,6 @@ import { useEffect, useState } from "react";
 import { createPortal } from "react-dom";
 import { usePopper } from "react-popper";
 import { useEvent } from "react-use";
-import useLazyRef from "~/hooks/useLazyRef";
 
 // Recharts 3.x will have portal support, but until then we're using this:
 //https://github.com/recharts/recharts/issues/2458#issuecomment-1063463873
@@ -33,13 +32,9 @@ export interface PopperPortalProps {
 export default function TooltipPortal({ active = true, children }: PopperPortalProps) {
   const [portalElement, setPortalElement] = useState<HTMLDivElement>();
   const [popperElement, setPopperElement] = useState<HTMLDivElement | null>();
-  const virtualElementRef = useLazyRef(() => new VirtualElement());
+  const [virtualElement] = useState(() => new VirtualElement());
 
-  const { styles, attributes, update } = usePopper(
-    virtualElementRef.current,
-    popperElement,
-    POPPER_OPTIONS
-  );
+  const { styles, attributes, update } = usePopper(virtualElement, popperElement, POPPER_OPTIONS);
 
   useEffect(() => {
     const el = document.createElement("div");
@@ -50,7 +45,7 @@ export default function TooltipPortal({ active = true, children }: PopperPortalP
   }, []);
 
   useEvent("mousemove", ({ clientX: x, clientY: y }) => {
-    virtualElementRef.current?.update(x, y);
+    virtualElement.update(x, y);
     if (!active) return;
     update?.();
   });
@@ -59,9 +54,9 @@ export default function TooltipPortal({ active = true, children }: PopperPortalP
     if (!active) return;
     // Seed from the last known pointer so the tooltip appears at the cursor immediately, even if the
     // mouse is held still after hovering onto a point (otherwise it flashes in the top-left corner).
-    virtualElementRef.current?.update(lastPointer.x, lastPointer.y);
+    virtualElement.update(lastPointer.x, lastPointer.y);
     update?.();
-  }, [active, update, virtualElementRef]);
+  }, [active, update, virtualElement]);
 
   if (!portalElement) return null;
 

apps/webapp/app/hooks/useLazyRef.ts

@@ -1,12 +0,0 @@
-import type { MutableRefObject } from "react";
-import { useRef } from "react";
-
-const useLazyRef = <T>(initialValFunc: () => T) => {
-  const ref: MutableRefObject<T | null> = useRef(null);
-  if (ref.current === null) {
-    ref.current = initialValFunc();
-  }
-  return ref;
-};
-
-export default useLazyRef;