From 98fc0c36dc0dc4d390b105ebd012e49da959fd03 Mon Sep 17 00:00:00 2001
From: Damon <damon@vestervand.net>
Date: Fri, 10 Jun 2022 13:20:02 +0200
Subject: [PATCH] Add custom merge function option

---
 packages/lib/search/use-acter-search.ts       |  1 +
 .../pagainated-results.reducer.test.ts        | 40 +++++++++++++++++--
 .../paginated-results-reducer.ts              | 15 ++++---
 .../lib/urql/use-paginated-query/types.ts     | 23 ++++++++---
 .../use-paginated-query.ts                    |  5 ++-
 5 files changed, 68 insertions(+), 16 deletions(-)

diff --git a/packages/lib/search/use-acter-search.ts b/packages/lib/search/use-acter-search.ts
index ff946e9d0..5547af28f 100644
--- a/packages/lib/search/use-acter-search.ts
+++ b/packages/lib/search/use-acter-search.ts
@@ -22,6 +22,7 @@ export interface UseActerSearchQueryResults
 }
 
 type UseActerSearchOptions = UsePaginationQueryOptions<
+  Acter,
   ActerSearchData,
   SearchVariables
 >
diff --git a/packages/lib/urql/use-paginated-query/pagainated-results.reducer.test.ts b/packages/lib/urql/use-paginated-query/pagainated-results.reducer.test.ts
index 843989b85..ca30cc08c 100644
--- a/packages/lib/urql/use-paginated-query/pagainated-results.reducer.test.ts
+++ b/packages/lib/urql/use-paginated-query/pagainated-results.reducer.test.ts
@@ -5,7 +5,7 @@ import {
   GetPaginatedResultsReducer,
   PaginatedResultsActionKind,
   PaginatedResultsState,
-  ResultsType,
+  StateResultsType,
 } from './types'
 
 describe('paginatedResultsReducer', () => {
@@ -134,7 +134,7 @@ describe('paginatedResultsReducer', () => {
               results: OrderedMap({
                 1: { id: 1 },
                 2: { id: 2 },
-              }) as ResultsType,
+              }) as StateResultsType,
             },
             {
               type: PaginatedResultsActionKind.NEW_RESULTS,
@@ -156,7 +156,7 @@ describe('paginatedResultsReducer', () => {
               results: OrderedMap({
                 1: { id: 1 },
                 2: { id: 2 },
-              }) as ResultsType,
+              }) as StateResultsType,
             },
             {
               type: PaginatedResultsActionKind.NEW_RESULTS,
@@ -172,6 +172,40 @@ describe('paginatedResultsReducer', () => {
         })
       })
 
+      describe('resultsMergeFn', () => {
+        it('should allow for different merge strategies', () => {
+          const result = getPaginatedResultsReducer<
+            { id: number; foo: string },
+            unknown,
+            unknown
+          >({
+            resultsMergeFn: (state, item) =>
+              state.set(item.id.toString(), {
+                ...item,
+                foo: 'bar'.repeat(item.id),
+              }),
+          })
+          reducer = result[0]
+          const newResults = [{ id: 1 }, { id: 2 }, { id: 3 }]
+          const state = reducer(
+            {
+              ...defaultState,
+              results: OrderedMap() as StateResultsType,
+            },
+            {
+              type: PaginatedResultsActionKind.NEW_RESULTS,
+              payload: { results: newResults },
+            }
+          )
+
+          expect(state.results.toList().toArray()).toStrictEqual([
+            { id: 1, foo: 'bar' },
+            { id: 2, foo: 'barbar' },
+            { id: 3, foo: 'barbarbar' },
+          ])
+        })
+      })
+
       describe('loadMore', () => {
         it('should return if there are no results to load more from', () => {
           const state = reducer(
diff --git a/packages/lib/urql/use-paginated-query/paginated-results-reducer.ts b/packages/lib/urql/use-paginated-query/paginated-results-reducer.ts
index 7e67f1cdd..ee444dca9 100644
--- a/packages/lib/urql/use-paginated-query/paginated-results-reducer.ts
+++ b/packages/lib/urql/use-paginated-query/paginated-results-reducer.ts
@@ -14,11 +14,14 @@ export const getPaginatedResultsReducer = <
   TType extends WithId,
   TData,
   TVariables
->(
-  { pageSize }: GetPaginatedResultsReducerProps = {
-    pageSize: 20,
-  }
-): GetPaginatedResultsReducerResult<TType, TData, TVariables> => {
+>({
+  pageSize = 20,
+  resultsMergeFn = (map, item) => map.set(item.id.toString(), item),
+}: GetPaginatedResultsReducerProps<TType> = {}): GetPaginatedResultsReducerResult<
+  TType,
+  TData,
+  TVariables
+> => {
   type ReducerState = PaginatedResultsState<TType, TData, TVariables>
 
   const defaultPagination: Pagination = {
@@ -57,7 +60,7 @@ export const getPaginatedResultsReducer = <
             const sliceEnd = hasMore ? -1 : undefined
             const nextResultsPage = results.slice(0, sliceEnd)
             const newResults = nextResultsPage.reduce(
-              (map, item) => map.set(item.id.toString(), item),
+              resultsMergeFn,
               state.results
             )
             return {
diff --git a/packages/lib/urql/use-paginated-query/types.ts b/packages/lib/urql/use-paginated-query/types.ts
index 1d1303031..16085361a 100644
--- a/packages/lib/urql/use-paginated-query/types.ts
+++ b/packages/lib/urql/use-paginated-query/types.ts
@@ -11,10 +11,13 @@ export interface Pagination {
   take: number
 }
 
-export type ResultsType<TType = unknown> = OrderedMap<string | number, TType>
+export type StateResultsType<TType = unknown> = OrderedMap<
+  string | number,
+  TType
+>
 export interface PaginatedResultsState<TType, TData, TVariables>
   extends UseQueryState<TData, TVariables> {
-  results: ResultsType<TType>
+  results: StateResultsType<TType>
   fetching: boolean
   hasMore: boolean
   pagination: Pagination
@@ -36,8 +39,14 @@ export interface PaginatedResultsAction<TType> {
   payload?: PaginatedResultsActionPayload<TType>
 }
 
-export interface GetPaginatedResultsReducerProps {
+export type ResultsMergeFn<TType = unknown> = (
+  state: StateResultsType<TType>,
+  results: TType
+) => StateResultsType<TType>
+
+export interface GetPaginatedResultsReducerProps<TType = unknown> {
   pageSize?: number
+  resultsMergeFn?: ResultsMergeFn<TType>
 }
 
 export type GetPaginatedResultsReducer<TType, TData, TVariables> = Reducer<
@@ -67,7 +76,7 @@ export type VariablesWithPagination<TVariables> = TVariables & Pagination
 
 export interface UsePaginatedState<TType = any, TData = any, TVariables = any>
   extends UseQueryState<TData, TVariables> {
-  results: ResultsType<TType>
+  results: StateResultsType<TType>
   fetching: boolean
   hasMore: boolean
   pagination: Pagination
@@ -80,7 +89,7 @@ export type UsePaginatedResponse<TType, TData, TVariables> = [
   UsePaginatedState<TType, TData, TVariables>,
   refetch<TVariables>
 ]
-export interface UsePaginationQueryOptions<TData, TVariables>
+export interface UsePaginationQueryOptions<TType, TData, TVariables>
   extends UseQueryArgs<TVariables, TData> {
   /**
    * The GraphQL query
@@ -102,6 +111,10 @@ export interface UsePaginationQueryOptions<TData, TVariables>
    * Pagination options
    */
   pagination?: Pagination
+  /**
+   * Merge function to use for new results
+   */
+  resultsMergeFn?: ResultsMergeFn<TType>
 }
 
 export type WithId = {
diff --git a/packages/lib/urql/use-paginated-query/use-paginated-query.ts b/packages/lib/urql/use-paginated-query/use-paginated-query.ts
index e4cc69229..6ae7ac68f 100644
--- a/packages/lib/urql/use-paginated-query/use-paginated-query.ts
+++ b/packages/lib/urql/use-paginated-query/use-paginated-query.ts
@@ -13,13 +13,14 @@ import {
 } from './types'
 
 export const usePaginatedQuery = <TType extends WithId, TData, TVariables>(
-  options: UsePaginationQueryOptions<TData, TVariables>
+  options: UsePaginationQueryOptions<TType, TData, TVariables>
 ): UsePaginatedResponse<TType, TData, TVariables> => {
-  const { query, dataKey, variables, pageSize = 10 } = options
+  const { query, dataKey, variables, pageSize = 10, resultsMergeFn } = options
 
   const [paginatedResultsReducer, { defaultState }] =
     getPaginatedResultsReducer<TType, TData, TVariables>({
       pageSize,
+      resultsMergeFn,
     })
   const [state, dispatch] = useReducer(paginatedResultsReducer, defaultState)