From d9c6f1ea87f47c59435f7eda89dd9ec1cc7e7096 Mon Sep 17 00:00:00 2001
From: Shu Ding <g@shud.in>
Date: Tue, 17 Aug 2021 14:43:17 +0200
Subject: [PATCH] fix: add trigger symbol

---
 src/use-swr.ts      | 13 ++++++++++++-
 src/utils/helper.ts |  4 ++++
 trigger/index.ts    |  5 +++--
 3 files changed, 19 insertions(+), 3 deletions(-)

diff --git a/src/use-swr.ts b/src/use-swr.ts
index e8e5aefec..d028f8e2d 100644
--- a/src/use-swr.ts
+++ b/src/use-swr.ts
@@ -3,7 +3,12 @@ import defaultConfig from './utils/config'
 import { wrapCache, SWRGlobalState, GlobalState } from './utils/cache'
 import { IS_SERVER, rAF, useIsomorphicLayoutEffect } from './utils/env'
 import { serialize } from './utils/serialize'
-import { isThenable, isUndefined, UNDEFINED } from './utils/helper'
+import {
+  isThenable,
+  isUndefined,
+  UNDEFINED,
+  TriggerSymbol
+} from './utils/helper'
 import ConfigProvider from './utils/config-context'
 import useStateWithDeps from './utils/state'
 import withArgs from './utils/resolve-args'
@@ -449,6 +454,12 @@ export const useSWRHandler = <Data = any, Error = any>(
   // `mutate`, but bound to the current key.
   const boundMutate: SWRResponse<Data, Error>['mutate'] = useCallback(
     (newData, shouldRevalidate) => {
+      // To add internal options without affecting the API, we use Symbol as the
+      // argument to specialize it.
+      if ((newData as any) === TriggerSymbol) {
+        return revalidate()
+      }
+
       return internalMutate(cache, keyRef.current, newData, shouldRevalidate)
     },
     // `cache` isn't allowed to change during the lifecycle
diff --git a/src/utils/helper.ts b/src/utils/helper.ts
index b01d1d1a9..90a1687ab 100644
--- a/src/utils/helper.ts
+++ b/src/utils/helper.ts
@@ -1,6 +1,10 @@
 // `undefined` can possibly be replaced by something else.
 export const UNDEFINED: undefined = ({} as any)[0]
+
 export const isUndefined = (v: any) => v === UNDEFINED
 export const isThenable = (v: any): v is Promise<any> =>
   v && typeof v.then === 'function'
+
+export const TriggerSymbol = Symbol.for('swr.t')
+
 export const noop = () => {}
diff --git a/trigger/index.ts b/trigger/index.ts
index 3442aa7a1..303068845 100644
--- a/trigger/index.ts
+++ b/trigger/index.ts
@@ -10,6 +10,7 @@ import useSWR, {
 import { useCallback, useRef } from 'react'
 
 import { withMiddleware } from '../src/utils/with-middleware'
+import { TriggerSymbol } from '../src/utils/helper'
 
 export const trigger = ((<Data, Error>(useSWRNext: SWRHook) => (
   key: Key,
@@ -48,8 +49,8 @@ export const trigger = ((<Data, Error>(useSWRNext: SWRHook) => (
       // Assign extra arguments to the ref, so the fetcher can access them later.
       extraArgsRef.current = extraArgs
 
-      // Mutate the SWR data and return the result.
-      return swr.mutate()
+      // Trigger a revalidation.
+      return swr.mutate(TriggerSymbol)
     },
     [swr.mutate]
   )