Add getStatus to createAsyncThunk to return promise state

etc/redux-toolkit.api.md

@@ -112,6 +112,7 @@ export function createAsyncThunk<Returned, ThunkArg = void, ThunkApiConfig exten
     aborted: boolean;
 }, SerializedError>> & {
     abort: (reason?: string | undefined) => void;
+    getStatus: () => "pending" | "rejected" | "fulfilled";
 }) & {
     pending: ActionCreatorWithPreparedPayload<[string, ThunkArg], undefined, string, never, {
         arg: ThunkArg;

src/createAsyncThunk.test.ts

@@ -293,6 +293,64 @@ describe('createAsyncThunk', () => {
     expect(errorAction.meta.requestId).toBe(generatedRequestId)
     expect(errorAction.meta.arg).toBe(args)
   })
+
+  it('returns the status of a fulfilled promise via getStatus()', async () => {
+    let store = configureStore({
+      reducer(store: AnyAction[] = []) {
+        return store
+      }
+    })
+
+    const args = 123
+    let generatedRequestId = ''
+
+    const longRunningAsyncThunk = createAsyncThunk(
+      'longRunning',
+      async (args: number, { requestId }) => {
+        generatedRequestId = requestId
+
+        await new Promise(resolve => setTimeout(resolve, 1000))
+      }
+    )
+
+    const promise = store.dispatch(longRunningAsyncThunk(args))
+    expect(promise.getStatus()).toEqual('pending')
+
+    const result = await promise
+    expect(promise.getStatus()).toEqual('fulfilled')
+    expect(result.type).toContain('fulfilled')
+    expect(result.meta.requestId).toBe(generatedRequestId)
+    expect(result.meta.arg).toBe(args)
+  })
+
+  it('returns the status of a rejected promise via getStatus()', async () => {
+    let store = configureStore({
+      reducer(store: AnyAction[] = []) {
+        return store
+      }
+    })
+
+    const args = 123
+    let generatedRequestId = ''
+
+    const errorThunk = createAsyncThunk(
+      'errorThunk',
+      async (args: number, { requestId }) => {
+        generatedRequestId = requestId
+
+        throw new Error('Panic!')
+      }
+    )
+
+    const promise = store.dispatch(errorThunk(args))
+    expect(promise.getStatus()).toEqual('pending')
+
+    const result = await promise
+    expect(promise.getStatus()).toEqual('rejected')
+    expect(result.type).toContain('rejected')
+    expect(result.meta.requestId).toBe(generatedRequestId)
+    expect(result.meta.arg).toBe(args)
+  })
 })
 
 describe('createAsyncThunk with abortController', () => {

src/createAsyncThunk.ts

@@ -201,6 +201,7 @@ If you want to use the AbortController to react to \`abort\` events, please cons
       getState: () => GetState<ThunkApiConfig>,
       extra: GetExtra<ThunkApiConfig>
     ) => {
+      let status: 'pending' | 'rejected' | 'fulfilled' = 'pending'
       const requestId = nanoid()
 
       const abortController = new AC()
@@ -217,9 +218,14 @@ If you want to use the AbortController to react to \`abort\` events, please cons
         abortController.abort()
       }
 
+      function getStatus() {
+        return status
+      }
+
       const promise = (async function() {
         let finalAction: ReturnType<typeof fulfilled | typeof rejected>
         try {
+          status = 'pending'
           dispatch(pending(requestId, arg))
           finalAction = await Promise.race([
             abortedPromise,
@@ -236,12 +242,15 @@ If you want to use the AbortController to react to \`abort\` events, please cons
               })
             ).then(result => {
               if (result instanceof RejectWithValue) {
+                status = 'rejected'
                 return rejected(null, requestId, arg, result.value)
               }
+              status = 'fulfilled'
               return fulfilled(result, requestId, arg)
             })
           ])
         } catch (err) {
+          status = 'rejected'
           finalAction = rejected(err, requestId, arg)
         }
         // We dispatch the result action _after_ the catch, to avoid having any errors
@@ -252,7 +261,7 @@ If you want to use the AbortController to react to \`abort\` events, please cons
         dispatch(finalAction)
         return finalAction
       })()
-      return Object.assign(promise, { abort })
+      return Object.assign(promise, { abort, getStatus })
     }
   }