Sequential execution / queue of endpoint of createApi - redux-toolkit

Question

One of my endpoints should be called one by one, since the backend doesnt support multiple parallel requests. Ive tried two ways to do it:
Using onQueryStarted:
const sequenceMutex = new Mutex()
async onQueryStarted(id, { dispatch, queryFulfilled }) {
// wait until the sequenceMutex is available
await sequenceMutex.waitForUnlock()
const releaseSequence = await sequenceMutex.acquire()
await queryFulfilled // the endpoint already started here, cant manage the execution
releaseSequence()
}
Using a different baseQuery. But I dont see any way to use a different baseQuery for an especific endpoint:
const sequenceMutex = new Mutex()
export const sequentialBaseQueryWithReauth = async (
args,
api,
extraOptions
) => {
// wait until the sequenceMutex is available
await sequenceMutex.waitForUnlock()
const releaseSequence = await sequenceMutex.acquire()
const result = await baseQueryWithAuthentication(args, api, extraOptions)
releaseSequence()
return result
}

Answer 1

You could iterate on your answer and kick that yourEndpointSequentialBaseQuery.
const apiSlice = api.injectEndpoints({
endpoints: (builder) => ({
yourEndpoint: builder.query({
queryFn: (args, api, extraOptions, baseQuery) => {
await mutex.waitForUnlock()
const releaseSequence = await mutex.acquire()
try {
return baseQuery({
url: '/your-route',
method: 'POST',
body: args,
})
} finally {
releaseSequence()
}
},
}),
}),
})

Answer 2

Finally I created a generic seuqnetial baseQuery function to reuse it across the app.
First, create a baseQuery that accepts a mutex instance as argument:
export const sequentialBaseQueryFactory = (mutex: InstanceType<typeof Mutex>) => {
const sequentialBaseQuery: BaseQueryFn<string | FetchArgs, unknown, FetchBaseQueryError> = async (
args,
api,
extraOptions,
) => {
await mutex.waitForUnlock()
const releaseSequence = await mutex.acquire()
const result = await yourBaseQuery(args, api, extraOptions) // use your createApi baseQuery
releaseSequence()
return result
}
return sequentialBaseQuery
}
Then, create the custom baseQuery for your endpoint using a mutex instance :
import { Mutex } from 'async-mutex'
// mutex for sequential calls of your endpoint
const yourEndpointSequenceMutex = new Mutex()
const yourEndpointSequentialBaseQuery = sequentialBaseQueryFactory(yourEndpointSequenceMutex)
Use the custom baseQuery in your endoint:
const apiSlice = api.injectEndpoints({
endpoints: (builder) => ({
yourEndpoint: builder.query({
queryFn: (args, api, extraOptions) => {
return yourEndpointSequentialBaseQuery({
url: '/your-route',
method: 'POST',
body: args,
}, api, extraOptions)
},
}),
}),
})