fix: not clear promise of revalidate after mutating

src/use-swr.ts

@@ -168,7 +168,7 @@ async function mutate<Data = any>(
   // enter the revalidation stage
   // update existing SWR Hooks' state
   const updaters = CACHE_REVALIDATORS[key]
-  if (updaters) {
+  if (updaters && updaters.length) {
     const promises = []
     for (let i = 0; i < updaters.length; ++i) {
       promises.push(
@@ -180,6 +180,11 @@ async function mutate<Data = any>(
       if (error) throw error
       return cache.get(key)
     })
+  } else if (shouldRevalidate) {
+    // `updaters` would trigger revalidate if `updaters.length > 0`.
+    // So clear promise of revalidate if `!updaters.length && shouldRevalidate`
+    delete CONCURRENT_PROMISES[key]
+    delete CONCURRENT_PROMISES_TS[key]
   }
   // throw error or return data to be used by caller of mutate
   if (error) throw error

test/use-swr-revalidate.test.tsx

@@ -1,6 +1,6 @@
 import { act, fireEvent, render, screen } from '@testing-library/react'
-import React from 'react'
-import useSWR from '../src'
+import React, { useEffect, useState } from 'react'
+import useSWR, { mutate } from '../src'
 import { createResponse, sleep } from './utils'
 
 const waitForNextTick = () => act(() => sleep(1))
@@ -136,4 +136,52 @@ describe('useSWR - revalidate', () => {
     await act(() => sleep(70))
     screen.getByText('count: 2')
   })
+
+  it('cg test', async () => {
+    const swrKey = 'cg test'
+    function A() {
+      const { data } = useSWR(
+        swrKey,
+        async () => {
+          return 'A'
+        },
+        {
+          dedupingInterval: 6000
+        }
+      )
+      return <>{data}</>
+    }
+
+    function B() {
+      useEffect(() => {
+        mutate(swrKey, async () => {
+          return 'B'
+        })
+      }, [])
+      return null
+    }
+
+    function Page() {
+      const [isShowA, setIsShowA] = useState(true)
+
+      return (
+        <button
+          onClick={() => {
+            setIsShowA(!isShowA)
+          }}
+        >
+          click me {isShowA ? <A /> : <B />}
+        </button>
+      )
+    }
+
+    render(<Page />)
+
+    await act(() => sleep(20))
+    fireEvent.click(screen.getByText('click me A'))
+    await act(() => sleep(20))
+    fireEvent.click(screen.getByText('click me'))
+    await act(() => sleep(20))
+    screen.getByText('click me A')
+  })
 })