resolves vercel#1131 (vercel#1727)

Author: shuding

src/use-swr.ts

@@ -110,7 +110,7 @@ export const useSWRHandler = <Data = any, Error = any>(
   // Resolve the current validating state.
   const resolveValidating = () => {
     if (!key || !fetcher) return false
-    if (info.isValidating) return true
+    if (cache.get(keyValidating)) return true
 
     // If it's not mounted yet and it should revalidate on mount, revalidate.
     return isInitialMount && shouldRevalidate()
@@ -204,8 +204,9 @@ export const useSWRHandler = <Data = any, Error = any>(
             }, config.loadingTimeout)
           }
 
-          // Start the request and save the timestamp.
-          FETCH[key] = [currentFetcher(...fnArgs), getTimestamp()]
+          // Start the request and keep the timestamp.
+          CONCURRENT_PROMISES_TS[key] = getTimestamp()
+          CONCURRENT_PROMISES[key] = currentFetcher(...fnArgs)
         }
 
         // Wait until the ongoing request is done. Deduplication is also

test/use-swr-fetcher.test.tsx

@@ -1,5 +1,5 @@
-import { act, fireEvent, screen } from '@testing-library/react'
-import React, { Suspense, useState } from 'react'
+import { act, screen } from '@testing-library/react'
+import React, { useState } from 'react'
 import useSWR from 'swr'
 import { createKey, renderWithConfig, nextTick } from './utils'
 
@@ -33,74 +33,4 @@ describe('useSWR - fetcher', () => {
     // Should fetch with the new fetcher.
     await screen.findByText('data:bar')
   })
-
-  it('should use the latest fetcher reference when the key has been changed', async () => {
-    const key = createKey()
-    let fetcher = () => 'foo'
-
-    function Page() {
-      const [prefix, setPrefix] = useState('a')
-      const { data } = useSWR(prefix + key, fetcher)
-
-      return (
-        <div>
-          <p>data:{data}</p>
-          <button
-            onClick={() => {
-              setPrefix('b')
-            }}
-          >
-            mutate
-          </button>
-        </div>
-      )
-    }
-
-    renderWithConfig(<Page />)
-    await screen.findByText('data:foo')
-
-    // Change the fetcher and make sure the ref is updated.
-    fetcher = () => 'bar'
-    fireEvent.click(screen.getByText('mutate'))
-
-    // Should fetch with the new fetcher.
-    await screen.findByText('data:bar')
-  })
-
-  it('should use the latest fetcher reference with the suspense mode when the key has been changed', async () => {
-    const key = createKey()
-    let fetcher = () => 'foo'
-
-    function Page() {
-      const [prefix, setPrefix] = useState('a')
-      const { data } = useSWR(prefix + key, fetcher, { suspense: true })
-
-      return (
-        <div>
-          <p>data:{data}</p>
-          <button
-            onClick={() => {
-              setPrefix('b')
-            }}
-          >
-            mutate
-          </button>
-        </div>
-      )
-    }
-
-    renderWithConfig(
-      <Suspense fallback="loading">
-        <Page />
-      </Suspense>
-    )
-    await screen.findByText('data:foo')
-
-    // Change the fetcher and make sure the ref is updated.
-    fetcher = () => 'bar'
-    fireEvent.click(screen.getByText('mutate'))
-
-    // Should fetch with the new fetcher.
-    await screen.findByText('data:bar')
-  })
 })