Merge #808

808: Add ability to clear cache to allow real-time refresh of search results. r=bidoubiwa a=fadeaway

# Pull Request

## What does this PR do?
Fixes [#790](#790)

Implements clearCache method on InstantMeiliSearchInstance to allow realtime updates to search results. This allows algolias refresh example to work out of the box. ([https://www.algolia.com/doc/guides/building-search-ui/going-further/improve-performance/vue/#caching](https://www.algolia.com/doc/guides/building-search-ui/going-further/improve-performance/vue/#caching))


## PR checklist
Please check if your PR fulfills the following requirements:
- [X ] Does this PR fix an existing issue?
- [X ] Have you read the contributing guidelines?
- [X ] Have you made sure that the title is accurate and descriptive of the changes?

Thank you so much for contributing to Meilisearch!


Co-authored-by: Kyle Knowles <[email protected]>
Co-authored-by: Kyle Knowles <[email protected]>

src/cache/search-cache.ts

@@ -7,7 +7,7 @@ import { stringifyArray } from '../utils'
 export function SearchCache(
   cache: Record<string, string> = {}
 ): SearchCacheInterface {
-  const searchCache = cache
+  let searchCache = cache
   return {
     getEntry: function (key: string) {
       if (searchCache[key]) {
@@ -25,5 +25,8 @@ export function SearchCache(
     setEntry: function <T>(key: string, searchResponse: T) {
       searchCache[key] = JSON.stringify(searchResponse)
     },
+    clearCache: function () {
+      searchCache = {}
+    },
   }
 }

src/client/instant-meilisearch-client.ts

@@ -28,8 +28,9 @@ export function instantMeiliSearch(
   apiKey = '',
   instantMeiliSearchOptions: InstantMeiliSearchOptions = {}
 ): InstantMeiliSearchInstance {
+  const searchCache = SearchCache()
   // create search resolver with included cache
-  const searchResolver = SearchResolver(SearchCache())
+  const searchResolver = SearchResolver(searchCache)
   // paginationTotalHits can be 0 as it is a valid number
   let defaultFacetDistribution: any = {}
   const clientAgents = constructClientAgents(
@@ -43,6 +44,7 @@ export function instantMeiliSearch(
   })
 
   return {
+    clearCache: () => searchCache.clearCache(),
     /**
      * @param  {readonlyAlgoliaMultipleQueriesQuery[]} instantSearchRequests
      * @returns {Array}

src/types/types.ts

@@ -40,6 +40,7 @@ export type SearchCacheInterface = {
   getEntry: (key: string) => MeiliSearchResponse | undefined
   formatKey: (components: any[]) => string
   setEntry: <T>(key: string, searchResponse: T) => void
+  clearCache: () => void
 }
 
 export type InsideBoundingBox = string | ReadonlyArray<readonly number[]>
@@ -86,4 +87,6 @@ export type SearchContext = Omit<
   pagination: PaginationContext
 }
 
-export type InstantMeiliSearchInstance = SearchClient
+export type InstantMeiliSearchInstance = SearchClient & {
+  clearCache: () => void
+}