feat: Retry search with exponential backoff

Sometimes the search might return nothing because the indexes are not
ready yet. In such case, the user will get no search result and will
have to retry.
To avoid this, we now wait for the index to be ready by making several
retries, with exponential backoff

packages/cozy-dataproxy-lib/src/components/Search/useFetchResult.jsx

@@ -7,6 +7,31 @@ import { getIconForSearchResult } from './getIconForSearchResult'
 
 const log = Minilog('🔍 [useFetchResult]')
 
+const searchWithRetry = async (
+  dataProxy,
+  searchValue,
+  { maxRetries = 5, delay = 500 } = {}
+) => {
+  let currentDelay = delay
+  // Make several search attemps in case it is not ready yet
+  for (let attempt = 0; attempt < maxRetries; attempt++) {
+    const searchResults = await dataProxy.search(searchValue)
+
+    if (searchResults) {
+      // A successful search will return an array, and null otherwise
+      return searchResults
+    }
+    log.info(
+      `Search attempt ${attempt + 1} failed, retrying in ${currentDelay} ms...`
+    )
+    await new Promise(resolve => setTimeout(resolve, currentDelay))
+    currentDelay *= 2 // Exponential backoff
+  }
+
+  log.error(`Search failed after ${maxRetries} attempts`)
+  return []
+}
+
 export const useFetchResult = searchValue => {
   const [state, setState] = useState({
     isLoading: true,
@@ -24,7 +49,7 @@ export const useFetchResult = searchValue => {
 
       setState({ isLoading: true, results: null, searchValue })
 
-      const searchResults = await dataProxy.search(searchValue)
+      const searchResults = await searchWithRetry(dataProxy, searchValue)
 
       const results = searchResults.map(r => {
         // Begin Retrocompatibility code, to be removed when following PR is merged: https://github.com/cozy/cozy-web-data-proxy/pull/10

packages/cozy-dataproxy-lib/src/search/SearchEngine.ts

@@ -310,11 +310,14 @@ export class SearchEngine {
     return index
   }
 
-  search(query: string, options: SearchOptions | undefined): SearchResult[] {
-    if (!this.searchIndexes) {
-      // TODO: What if the indexing is running but not finished yet?
+  search(
+    query: string,
+    options: SearchOptions | undefined
+  ): SearchResult[] | null {
+    if (!this.searchIndexes || Object.keys(this.searchIndexes).length < 1) {
+      // The indexing might be running but not finished yet
       log.warn('[SEARCH] No search index available')
-      return []
+      return null
     }
 
     const allResults = this.searchOnIndexes(query, options?.doctypes)