Extract reusable helpers for writing cache entries

Author: markerikson

packages/toolkit/src/query/core/buildSlice.ts

@@ -112,6 +112,100 @@ export function buildSlice({
   >
 }) {
   const resetApiState = createAction(`${reducerPath}/resetApiState`)
+
+  function writePendingCacheEntry(
+    draft: QueryState<any>,
+    arg: QueryThunkArg,
+    upserting: boolean,
+    meta: {
+      arg: QueryThunkArg
+      requestId: string
+      // requestStatus: 'pending'
+    } & { startedTimeStamp: number },
+  ) {
+    draft[arg.queryCacheKey] ??= {
+      status: QueryStatus.uninitialized,
+      endpointName: arg.endpointName,
+    }
+
+    updateQuerySubstateIfExists(draft, arg.queryCacheKey, (substate) => {
+      substate.status = QueryStatus.pending
+
+      substate.requestId =
+        upserting && substate.requestId
+          ? // for `upsertQuery` **updates**, keep the current `requestId`
+            substate.requestId
+          : // for normal queries or `upsertQuery` **inserts** always update the `requestId`
+            meta.requestId
+      if (arg.originalArgs !== undefined) {
+        substate.originalArgs = arg.originalArgs
+      }
+      substate.startedTimeStamp = meta.startedTimeStamp
+    })
+  }
+
+  function writeFulfilledCacheEntry(
+    draft: QueryState<any>,
+    meta: {
+      arg: QueryThunkArg
+      requestId: string
+      // requestStatus: 'fulfilled'
+    } & {
+      fulfilledTimeStamp: number
+      baseQueryMeta: unknown
+      // RTK_autoBatch: true
+    },
+    payload: unknown,
+  ) {
+    updateQuerySubstateIfExists(draft, meta.arg.queryCacheKey, (substate) => {
+      if (substate.requestId !== meta.requestId && !isUpsertQuery(meta.arg))
+        return
+      const { merge } = definitions[meta.arg.endpointName] as QueryDefinition<
+        any,
+        any,
+        any,
+        any
+      >
+      substate.status = QueryStatus.fulfilled
+
+      if (merge) {
+        if (substate.data !== undefined) {
+          const { fulfilledTimeStamp, arg, baseQueryMeta, requestId } = meta
+          // There's existing cache data. Let the user merge it in themselves.
+          // We're already inside an Immer-powered reducer, and the user could just mutate `substate.data`
+          // themselves inside of `merge()`. But, they might also want to return a new value.
+          // Try to let Immer figure that part out, save the result, and assign it to `substate.data`.
+          let newData = createNextState(substate.data, (draftSubstateData) => {
+            // As usual with Immer, you can mutate _or_ return inside here, but not both
+            return merge(draftSubstateData, payload, {
+              arg: arg.originalArgs,
+              baseQueryMeta,
+              fulfilledTimeStamp,
+              requestId,
+            })
+          })
+          substate.data = newData
+        } else {
+          // Presumably a fresh request. Just cache the response data.
+          substate.data = payload
+        }
+      } else {
+        // Assign or safely update the cache data.
+        substate.data =
+          definitions[meta.arg.endpointName].structuralSharing ?? true
+            ? copyWithStructuralSharing(
+                isDraft(substate.data)
+                  ? original(substate.data)
+                  : substate.data,
+                payload,
+              )
+            : payload
+      }
+
+      delete substate.error
+      substate.fulfilledTimeStamp = meta.fulfilledTimeStamp
+    })
+  }
   const querySlice = createSlice({
     name: `${reducerPath}/queries`,
     initialState: initialState as QueryState<any>,
@@ -149,83 +243,10 @@ export function buildSlice({
       builder
         .addCase(queryThunk.pending, (draft, { meta, meta: { arg } }) => {
           const upserting = isUpsertQuery(arg)
-          draft[arg.queryCacheKey] ??= {
-            status: QueryStatus.uninitialized,
-            endpointName: arg.endpointName,
-          }
-
-          updateQuerySubstateIfExists(draft, arg.queryCacheKey, (substate) => {
-            substate.status = QueryStatus.pending
-
-            substate.requestId =
-              upserting && substate.requestId
-                ? // for `upsertQuery` **updates**, keep the current `requestId`
-                  substate.requestId
-                : // for normal queries or `upsertQuery` **inserts** always update the `requestId`
-                  meta.requestId
-            if (arg.originalArgs !== undefined) {
-              substate.originalArgs = arg.originalArgs
-            }
-            substate.startedTimeStamp = meta.startedTimeStamp
-          })
+          writePendingCacheEntry(draft, arg, upserting, meta)
         })
         .addCase(queryThunk.fulfilled, (draft, { meta, payload }) => {
-          updateQuerySubstateIfExists(
-            draft,
-            meta.arg.queryCacheKey,
-            (substate) => {
-              if (
-                substate.requestId !== meta.requestId &&
-                !isUpsertQuery(meta.arg)
-              )
-                return
-              const { merge } = definitions[
-                meta.arg.endpointName
-              ] as QueryDefinition<any, any, any, any>
-              substate.status = QueryStatus.fulfilled
-
-              if (merge) {
-                if (substate.data !== undefined) {
-                  const { fulfilledTimeStamp, arg, baseQueryMeta, requestId } =
-                    meta
-                  // There's existing cache data. Let the user merge it in themselves.
-                  // We're already inside an Immer-powered reducer, and the user could just mutate `substate.data`
-                  // themselves inside of `merge()`. But, they might also want to return a new value.
-                  // Try to let Immer figure that part out, save the result, and assign it to `substate.data`.
-                  let newData = createNextState(
-                    substate.data,
-                    (draftSubstateData) => {
-                      // As usual with Immer, you can mutate _or_ return inside here, but not both
-                      return merge(draftSubstateData, payload, {
-                        arg: arg.originalArgs,
-                        baseQueryMeta,
-                        fulfilledTimeStamp,
-                        requestId,
-                      })
-                    },
-                  )
-                  substate.data = newData
-                } else {
-                  // Presumably a fresh request. Just cache the response data.
-                  substate.data = payload
-                }
-              } else {
-                // Assign or safely update the cache data.
-                substate.data =
-                  definitions[meta.arg.endpointName].structuralSharing ?? true
-                    ? copyWithStructuralSharing(
-                        isDraft(substate.data)
-                          ? original(substate.data)
-                          : substate.data,
-                        payload,
-                      )
-                    : payload
-              }
-
-              delete substate.error
-              substate.fulfilledTimeStamp = meta.fulfilledTimeStamp
-            },
-          )
+          writeFulfilledCacheEntry(draft, meta, payload)
         })
         .addCase(
           queryThunk.rejected,