Fix some hydration issues (#1033)

* Extract `useIsClient` hook

* Fix a bunch of hydration bugs relevant to the contract page

web/components/contract/contract-details.tsx

@@ -34,6 +34,7 @@ import { ExtraContractActionsRow } from './extra-contract-actions-row'
 import { GroupLink } from 'common/group'
 import { Subtitle } from '../subtitle'
 import { useIsMobile } from 'web/hooks/use-is-mobile'
+import { useIsClient } from 'web/hooks/use-is-client'
 import {
   BountiedContractBadge,
   BountiedContractSmallBadge,
@@ -52,22 +53,23 @@ export function MiscDetails(props: {
   const { volume, closeTime, isResolved, createdTime, resolutionTime } =
     contract
 
+  const isClient = useIsClient()
   const isNew = createdTime > Date.now() - DAY_MS && !isResolved
   const groupToDisplay = getGroupLinkToDisplay(contract)
 
   return (
     <Row className="items-center gap-3 truncate text-sm text-gray-400">
-      {showTime === 'close-date' ? (
+      {isClient && showTime === 'close-date' ? (
         <Row className="gap-0.5 whitespace-nowrap">
           <ClockIcon className="h-5 w-5" />
           {(closeTime || 0) < Date.now() ? 'Closed' : 'Closes'}{' '}
           {fromNow(closeTime || 0)}
         </Row>
-      ) : showTime === 'resolve-date' && resolutionTime !== undefined ? (
+      ) : isClient && showTime === 'resolve-date' && resolutionTime ? (
         <Row className="gap-0.5">
           <ClockIcon className="h-5 w-5" />
           {'Resolved '}
-          {fromNow(resolutionTime || 0)}
+          {fromNow(resolutionTime)}
         </Row>
       ) : (contract?.featuredOnHomeRank ?? 0) > 0 ? (
         <FeaturedContractBadge />
@@ -390,6 +392,7 @@ function EditableCloseDate(props: {
 }) {
   const { closeTime, contract, isCreator, disabled } = props
 
+  const isClient = useIsClient()
   const dayJsCloseTime = dayjs(closeTime)
   const dayJsNow = dayjs()
 
@@ -452,7 +455,7 @@ function EditableCloseDate(props: {
               className="w-full shrink-0 sm:w-fit"
               onClick={(e) => e.stopPropagation()}
               onChange={(e) => setCloseDate(e.target.value)}
-              min={Date.now()}
+              min={isClient ? Date.now() : undefined}
               value={closeDate}
             />
             <Input
@@ -479,14 +482,18 @@ function EditableCloseDate(props: {
         </Col>
       </Modal>
       <DateTimeTooltip
-        text={closeTime > Date.now() ? 'Trading ends:' : 'Trading ended:'}
+        text={
+          isClient && closeTime <= Date.now()
+            ? 'Trading ended:'
+            : 'Trading ends:'
+        }
         time={closeTime}
       >
         <Row
           className={clsx(!disabled && isCreator ? 'cursor-pointer' : '')}
           onClick={() => !disabled && isCreator && setIsEditingCloseTime(true)}
         >
-          {isSameDay ? (
+          {isSameDay && isClient ? (
             <span className={'capitalize'}> {fromNow(closeTime)}</span>
           ) : isSameYear ? (
             dayJsCloseTime.format('MMM D')

web/components/contract/contract-mention.tsx

@@ -6,17 +6,19 @@ import { contractPath, getBinaryProbPercent } from 'web/lib/firebase/contracts'
 import { fromNow } from 'web/lib/util/time'
 import { BinaryContractOutcomeLabel } from '../outcome-label'
 import { getColor } from './quick-bet'
+import { useIsClient } from 'web/hooks/use-is-client'
 
 export function ContractMention(props: { contract: Contract }) {
   const { contract } = props
   const { outcomeType, resolution } = contract
   const probTextColor = `text-${getColor(contract)}`
+  const isClient = useIsClient()
 
   return (
     <Link href={contractPath(contract)}>
       <a
         className="group inline whitespace-nowrap rounded-sm hover:bg-indigo-50 focus:bg-indigo-50"
-        title={tooltipLabel(contract)}
+        title={isClient ? tooltipLabel(contract) : undefined}
       >
         <span className="break-anywhere mr-0.5 whitespace-normal font-normal text-indigo-700">
           {contract.question}

web/components/feed/copy-link-date-time.tsx

@@ -5,6 +5,7 @@ import Link from 'next/link'
 import { fromNow } from 'web/lib/util/time'
 import { ToastClipboard } from 'web/components/toast-clipboard'
 import { LinkIcon } from '@heroicons/react/outline'
+import { useIsClient } from 'web/hooks/use-is-client'
 
 export function CopyLinkDateTimeComponent(props: {
   prefix: string
@@ -14,6 +15,7 @@ export function CopyLinkDateTimeComponent(props: {
   className?: string
 }) {
   const { prefix, slug, elementId, createdTime, className } = props
+  const isClient = useIsClient()
   const [showToast, setShowToast] = useState(false)
 
   function copyLinkToComment(
@@ -36,7 +38,7 @@ export function CopyLinkDateTimeComponent(props: {
             'text-greyscale-4 hover:bg-greyscale-1.5 mx-1 whitespace-nowrap rounded-sm px-1 text-xs transition-colors'
           }
         >
-          {fromNow(createdTime)}
+          {isClient && fromNow(createdTime)}
           {showToast && <ToastClipboard />}
           <LinkIcon className="ml-1 mb-0.5 inline" height={13} />
         </a>

web/components/relative-timestamp.tsx

@@ -1,22 +1,16 @@
 import { DateTimeTooltip } from './datetime-tooltip'
-import React, { useEffect, useState } from 'react'
 import { fromNow } from 'web/lib/util/time'
+import { useIsClient } from 'web/hooks/use-is-client'
 
 export function RelativeTimestamp(props: { time: number }) {
   const { time } = props
-  const [isClient, setIsClient] = useState(false)
-
-  useEffect(() => {
-    // Only render on client to prevent difference from server.
-    setIsClient(true)
-  }, [])
-
+  const isClient = useIsClient()
   return (
     <DateTimeTooltip
       className="ml-1 whitespace-nowrap text-gray-400"
       time={time}
     >
-      {isClient ? fromNow(time) : ''}
+      {isClient && fromNow(time)}
     </DateTimeTooltip>
   )
 }

web/hooks/use-is-client.ts

@@ -0,0 +1,7 @@
+import { useEffect, useState } from 'react'
+
+export const useIsClient = () => {
+  const [isClient, setIsClient] = useState(false)
+  useEffect(() => setIsClient(true), [])
+  return isClient
+}