types: fix some mutation type issue

_internal/types.ts

@@ -373,7 +373,7 @@ export interface ScopedMutator<Data = any> {
 }
 
 export type KeyedMutator<Data> = (
-  data?: Data | Promise<Data> | MutatorCallback<Data>,
+  data?: Data | Promise<Data | undefined> | MutatorCallback<Data>,
   opts?: boolean | MutatorOptions<Data>
 ) => Promise<Data | undefined>
 

infinite/index.ts

@@ -197,7 +197,11 @@ export const infinite = (<Data, Error>(useSWRNext: SWRHook) =>
     const mutate = useCallback(
       // eslint-disable-next-line func-names
       function (
-        data?: undefined | Data[] | Promise<Data[]> | MutatorCallback<Data[]>,
+        data?:
+          | undefined
+          | Data[]
+          | Promise<Data[] | undefined>
+          | MutatorCallback<Data[]>,
         opts?: undefined | boolean | MutatorOptions<Data[]>
       ) {
         // When passing as a boolean, it's explicitly used to disable/enable

mutation/types.ts

@@ -1,4 +1,4 @@
-import type { SWRResponse, Key, MutatorOptions } from 'swr'
+import type { SWRResponse, Key } from 'swr'
 
 type FetcherResponse<Data> = Data | Promise<Data>
 
@@ -22,29 +22,37 @@ export type SWRMutationConfiguration<
   Data,
   Error,
   ExtraArg = any,
-  SWRMutationKey extends Key = Key
-> = MutatorOptions<Data> & {
+  SWRMutationKey extends Key = Key,
+  SWRData = any
+> = {
+  revalidate?: boolean
+  populateCache?:
+    | boolean
+    | ((result: Data, currentData: SWRData | undefined) => SWRData)
+  optimisticData?: SWRData | ((currentData?: SWRData) => SWRData)
+  rollbackOnError?: boolean | ((error: unknown) => boolean)
+  throwOnError?: boolean
   fetcher?: MutationFetcher<Data, ExtraArg, SWRMutationKey>
   onSuccess?: (
     data: Data,
     key: string,
     config: Readonly<
-      SWRMutationConfiguration<Data, Error, ExtraArg, SWRMutationKey>
+      SWRMutationConfiguration<Data, Error, ExtraArg, SWRMutationKey, SWRData>
     >
   ) => void
   onError?: (
     err: Error,
     key: string,
     config: Readonly<
-      SWRMutationConfiguration<Data, Error, ExtraArg, SWRMutationKey>
+      SWRMutationConfiguration<Data, Error, ExtraArg, SWRMutationKey, SWRData>
     >
   ) => void
 }
 
 export interface SWRMutationResponse<
   Data = any,
   Error = any,
-  ExtraArg = any,
+  ExtraArg = never,
   SWRMutationKey extends Key = Key
 > extends Pick<SWRResponse<Data, Error>, 'data' | 'error'> {
   /**
@@ -55,10 +63,27 @@ export interface SWRMutationResponse<
    * Function to trigger the mutation. You can also pass an extra argument to
    * the fetcher, and override the options for the mutation hook.
    */
-  trigger: (
-    extraArgument?: ExtraArg,
-    options?: SWRMutationConfiguration<Data, Error, ExtraArg, SWRMutationKey>
-  ) => Promise<Data | undefined>
+  trigger: [ExtraArg] extends [never]
+    ? <SWRData = Data>(
+        extraArgument?: null,
+        options?: SWRMutationConfiguration<
+          Data,
+          Error,
+          ExtraArg,
+          SWRMutationKey,
+          SWRData
+        >
+      ) => Promise<Data | undefined>
+    : <SWRData = Data>(
+        extraArgument: ExtraArg,
+        options?: SWRMutationConfiguration<
+          Data,
+          Error,
+          ExtraArg,
+          SWRMutationKey,
+          SWRData
+        >
+      ) => Promise<Data | undefined>
   /**
    * Function to reset the mutation state (`data`, `error`, and `isMutating`).
    */
@@ -69,7 +94,7 @@ export type SWRMutationHook = <
   Data = any,
   Error = any,
   SWRMutationKey extends Key = Key,
-  ExtraArg = any
+  ExtraArg = never
 >(
   /**
    * The key of the resource that will be mutated. It should be the same key

test/type/mutator.ts

@@ -1,6 +1,5 @@
 import type { Equal, Expect } from '@type-challenges/utils'
 import useSWR, { useSWRConfig } from 'swr'
-
 import type {
   MutatorFn,
   Key,

test/type/trigger.ts

@@ -1,5 +1,5 @@
 import useSWRMutation from 'swr/mutation'
-
+import useSWR from 'swr'
 type ExpectType = <T>(value: T) => void
 const expectType: ExpectType = () => {}
 
@@ -14,7 +14,7 @@ export function useExtraParam() {
     expectType<string>(key)
   })
   useSWRMutation('/api/user', (_, opts) => {
-    expectType<Equal<typeof opts, Readonly<{ arg: any }>>>(true)
+    expectType<Equal<typeof opts, Readonly<{ arg: never }>>>(true)
   })
 }
 
@@ -25,8 +25,7 @@ export function useTrigger() {
   )
 
   // The argument of `trigger` should be number or undefined.
-  // TODO: handle the `undefined` cases.
-  expectType<Equal<Parameters<typeof trigger>[0], number | undefined>>(true)
+  expectType<Equal<Parameters<typeof trigger>[0], number>>(true)
   expectType<Promise<string | undefined>>(trigger(1))
 
   // Other return values
@@ -49,7 +48,61 @@ export function useTriggerWithParameter() {
   )
 
   // The argument of `trigger` should be number or undefined.
-  // TODO: handle the `undefined` cases.
-  expectType<Equal<Parameters<typeof trigger>[0], number | undefined>>(true)
+  expectType<Equal<Parameters<typeof trigger>[0], number>>(true)
   expectType<Promise<string | undefined>>(trigger(1))
 }
+
+export function useTestSWRMutation() {
+  const { data } = useSWR('key', async () => {
+    return ['foo']
+  })
+  const { trigger } = useSWRMutation(
+    'key',
+    async (_, { arg }: { arg: 'foo' }) => {
+      return arg.toUpperCase()
+    }
+  )
+
+  const test = () => {
+    // @ts-expect-error `arg` should be 'foo'
+    trigger()
+
+    // @ts-expect-error `arg` should be 'foo'
+    trigger<typeof data>('bar', {
+      optimisticData: current => {
+        expectType<string[] | undefined>(current)
+        return []
+      },
+      populateCache: (added, current) => {
+        expectType<string>(added)
+        expectType<typeof data>(current)
+        return []
+      },
+      revalidate: false
+    })
+  }
+  test()
+}
+
+export function useTestSWRMutationWithSWRMutate() {
+  const { mutate } = useSWR('/some/key', () => {
+    return {
+      foo: 'bar'
+    }
+  })
+  const { trigger } = useSWRMutation('/some/key', () => {
+    return {
+      foo: 'foo'
+    }
+  })
+  const test = () => {
+    ;async () => {
+      mutate(trigger(), {
+        optimisticData: {
+          foo: 'baz'
+        }
+      })
+    }
+  }
+  test()
+}

test/use-swr-remote-mutation.test.tsx

@@ -56,7 +56,7 @@ describe('useSWR - remote mutation', () => {
 
   it('should trigger request with the correct argument signature', async () => {
     const key = createKey()
-    const fetcher = jest.fn(() => 'data')
+    const fetcher = jest.fn((_, __: { arg: string }) => 'data')
 
     function Page() {
       const { data, trigger } = useSWRMutation([key, 'arg0'], fetcher)
@@ -112,7 +112,7 @@ describe('useSWR - remote mutation', () => {
     function Page() {
       const { data, trigger } = useSWRMutation(key, () => 'data')
       return (
-        <button onClick={() => trigger(undefined, { onSuccess })}>
+        <button onClick={() => trigger(null, { onSuccess })}>
           {data || 'pending'}
         </button>
       )
@@ -235,7 +235,7 @@ describe('useSWR - remote mutation', () => {
     function Page() {
       const { data, error, trigger } = useSWRMutation(
         key,
-        async (_, { arg: shouldReturnValue }) => {
+        async (_, { arg: shouldReturnValue }: { arg: boolean }) => {
           await sleep(10)
           if (shouldReturnValue) return 'data'
           throw new Error('error')
@@ -344,7 +344,10 @@ describe('useSWR - remote mutation', () => {
 
     function Page() {
       const { data } = useSWR(key, () => 'data')
-      const { trigger } = useSWRMutation(key, (_, { arg }) => arg)
+      const { trigger } = useSWRMutation(
+        key,
+        (_, { arg }: { arg: string }) => arg
+      )
       return (
         <div onClick={() => trigger('updated!', { populateCache: true })}>
           data:{data || 'none'}
@@ -369,7 +372,10 @@ describe('useSWR - remote mutation', () => {
 
     function Page() {
       const { data } = useSWR(key, () => 'data')
-      const { trigger } = useSWRMutation(key, (_, { arg }) => arg)
+      const { trigger } = useSWRMutation(
+        key,
+        (_, { arg }: { arg: string }) => arg
+      )
       return (
         <div
           onClick={() =>
@@ -810,16 +816,19 @@ describe('useSWR - remote mutation', () => {
         await sleep(10)
         return ['foo']
       })
-      const { trigger } = useSWRMutation(key, async (_, { arg }) => {
-        await sleep(20)
-        return arg.toUpperCase()
-      })
+      const { trigger } = useSWRMutation(
+        key,
+        async (_, { arg }: { arg: string }) => {
+          await sleep(20)
+          return arg.toUpperCase()
+        }
+      )
 
       return (
         <div>
           <button
             onClick={() =>
-              trigger('bar', {
+              trigger<typeof data>('bar', {
                 optimisticData: current => [...current, 'bar'],
                 populateCache: (added, current) => [...current, added],
                 revalidate: false
@@ -859,7 +868,7 @@ describe('useSWR - remote mutation', () => {
     function Page() {
       const { error, trigger } = useSWRMutation(
         key,
-        async (_, { arg: shouldReturnValue }) => {
+        async (_, { arg: shouldReturnValue }: { arg: boolean }) => {
           await sleep(10)
           if (shouldReturnValue) return ['foo']
           throw new Error('error')