fix: Read queued updates when initialising state (#703)

* fix: Read queued updates when initialising state

Closes #702.

* test: Add non-regression test

packages/e2e/cypress/e2e/repro-702.cy.js

@@ -0,0 +1,24 @@
+/// <reference types="cypress" />
+
+describe('repro-702', () => {
+  it('mounts components with the correct state on load', () => {
+    cy.visit('/app/repro-702?a=test&b=test')
+    cy.get('#conditional-a-useQueryState').should('have.text', 'test pass')
+    cy.get('#conditional-a-useQueryStates').should('have.text', 'test pass')
+    cy.get('#conditional-b-useQueryState').should('have.text', 'test pass')
+    cy.get('#conditional-b-useQueryStates').should('have.text', 'test pass')
+  })
+
+  it('mounts components with the correct state after an update', () => {
+    cy.visit('/app/repro-702')
+    cy.contains('#hydration-marker', 'hydrated').should('be.hidden')
+
+    cy.get('#trigger-a').click()
+    cy.get('#conditional-a-useQueryState').should('have.text', 'test pass')
+    cy.get('#conditional-a-useQueryStates').should('have.text', 'test pass')
+
+    cy.get('#trigger-b').click()
+    cy.get('#conditional-b-useQueryState').should('have.text', 'test pass')
+    cy.get('#conditional-b-useQueryStates').should('have.text', 'test pass')
+  })
+})

packages/e2e/src/app/app/repro-702/page.tsx

@@ -0,0 +1,110 @@
+'use client'
+
+import { parseAsString, useQueryState, useQueryStates } from 'nuqs'
+import { Suspense, useRef } from 'react'
+
+export default function Page() {
+  return (
+    <Suspense>
+      <Client />
+    </Suspense>
+  )
+}
+
+function Client() {
+  return (
+    <>
+      <TriggerA />
+      <TriggerB />
+      <SwitchComponentA />
+      <SwitchComponentB />
+    </>
+  )
+}
+
+// using useQueryState
+function TriggerA() {
+  const [, setState] = useQueryState('a')
+  return (
+    <button id="trigger-a" onClick={() => setState('test')}>
+      Trigger A (via useQueryState)
+    </button>
+  )
+}
+
+// using useQueryStates
+function TriggerB() {
+  const [, setState] = useQueryStates({
+    b: parseAsString
+  })
+  return (
+    <button id="trigger-b" onClick={() => setState({ b: 'test' })}>
+      Trigger B (via useQueryStates)
+    </button>
+  )
+}
+
+function SwitchComponentA() {
+  const [x] = useQueryState('a')
+  if (x === 'test') {
+    return <ConditionalComponentA />
+  }
+  return null
+}
+
+function SwitchComponentB() {
+  const [x] = useQueryState('b')
+  if (x === 'test') {
+    return <ConditionalComponentB />
+  }
+  return null
+}
+
+function ConditionalComponentA() {
+  const nullCheckUseQueryState = useRef(false)
+  const nullCheckUseQueryStates = useRef(false)
+  const [fromUseQueryState] = useQueryState('a')
+  const [{ a: fromUseQueryStates }] = useQueryStates({ a: parseAsString })
+
+  if (fromUseQueryState === null) {
+    nullCheckUseQueryState.current = true
+  }
+  if (fromUseQueryStates === null) {
+    nullCheckUseQueryStates.current = true
+  }
+
+  return (
+    <>
+      <div id="conditional-a-useQueryState">
+        {fromUseQueryState} {nullCheckUseQueryState.current ? 'fail' : 'pass'}
+      </div>
+      <div id="conditional-a-useQueryStates">
+        {fromUseQueryStates} {nullCheckUseQueryStates.current ? 'fail' : 'pass'}
+      </div>
+    </>
+  )
+}
+
+function ConditionalComponentB() {
+  const nullCheckUseQueryState = useRef(false)
+  const nullCheckUseQueryStates = useRef(false)
+  const [fromUseQueryState] = useQueryState('b')
+  const [{ b: fromUseQueryStates }] = useQueryStates({ b: parseAsString })
+
+  if (fromUseQueryState === null) {
+    nullCheckUseQueryState.current = true
+  }
+  if (fromUseQueryStates === null) {
+    nullCheckUseQueryStates.current = true
+  }
+  return (
+    <>
+      <div id="conditional-b-useQueryState">
+        {fromUseQueryState} {nullCheckUseQueryState.current ? 'fail' : 'pass'}
+      </div>
+      <div id="conditional-b-useQueryStates">
+        {fromUseQueryStates} {nullCheckUseQueryStates.current ? 'fail' : 'pass'}
+      </div>
+    </>
+  )
+}

packages/nuqs/src/update-queue.ts

@@ -21,6 +21,10 @@ const transitionsQueue: Set<React.TransitionStartFunction> = new Set()
 let lastFlushTimestamp = 0
 let flushPromiseCache: Promise<URLSearchParams> | null = null
 
+export function getQueuedValue(key: string) {
+  return updateQueue.get(key)
+}
+
 export function enqueueQueryStringUpdate<Value>(
   key: string,
   value: Value | null,

packages/nuqs/src/useQueryState.ts

@@ -13,6 +13,7 @@ import { emitter, type CrossHookSyncPayload } from './sync'
 import {
   FLUSH_RATE_LIMIT_MS,
   enqueueQueryStringUpdate,
+  getQueuedValue,
   scheduleFlushToURL
 } from './update-queue'
 import { safeParse } from './utils'
@@ -235,7 +236,11 @@ export function useQueryState<T = string>(
   } = useAdapter()
   const queryRef = useRef<string | null>(initialSearchParams?.get(key) ?? null)
   const [internalState, setInternalState] = useState<T | null>(() => {
-    const query = initialSearchParams?.get(key) ?? null
+    const queuedQuery = getQueuedValue(key)
+    const query =
+      queuedQuery === undefined
+        ? (initialSearchParams?.get(key) ?? null)
+        : queuedQuery
     return query === null ? null : safeParse(parse, query, key)
   })
   const stateRef = useRef(internalState)

packages/nuqs/src/useQueryStates.ts

@@ -14,6 +14,7 @@ import { emitter, type CrossHookSyncPayload } from './sync'
 import {
   FLUSH_RATE_LIMIT_MS,
   enqueueQueryStringUpdate,
+  getQueuedValue,
   scheduleFlushToURL
 } from './update-queue'
 import { safeParse } from './utils'
@@ -258,7 +259,11 @@ function parseMap<KeyMap extends UseQueryStatesKeysMap>(
   return Object.keys(keyMap).reduce((obj, stateKey) => {
     const urlKey = urlKeys?.[stateKey] ?? stateKey
     const { defaultValue, parse } = keyMap[stateKey]!
-    const query = searchParams?.get(urlKey) ?? null
+    const queuedQuery = getQueuedValue(urlKey)
+    const query =
+      queuedQuery === undefined
+        ? (searchParams?.get(urlKey) ?? null)
+        : queuedQuery
     if (cachedQuery && cachedState && cachedQuery[urlKey] === query) {
       obj[stateKey as keyof KeyMap] =
         cachedState[stateKey] ?? defaultValue ?? null