Fix refetchInterval infinite loop (#404)

* use queryRef to avoid infinite loop in refetch interval effect

* fix original config being mutated by config from another hook instance

* store refetchIntervalId and fix refetchInterval comparison

* clear query.currentRefetchInterval on cleanup

Author: cherniavskii

src/queryCache.js

@@ -110,7 +110,7 @@ export function makeQueryCache() {
 
     if (query) {
       Object.assign(query, { queryVariables, queryFn })
-      Object.assign(query.config, config)
+      query.config = { ...query.config, ...config }
     } else {
       query = makeQuery({
         queryKey,

src/useBaseQuery.js

@@ -89,28 +89,28 @@ export function useBaseQuery(queryKey, queryVariables, queryFn, config = {}) {
 
   // Handle refetch interval
   React.useEffect(() => {
+    const query = queryRef.current
     if (
       config.refetchInterval &&
-      (!query.refetchInterval || config.refetchInterval < query.refetchInterval)
+      (!query.currentRefetchInterval ||
+        // shorter interval should override previous one
+        config.refetchInterval < query.currentRefetchInterval)
     ) {
-      clearInterval(query.refetchInterval)
-      query.refetchInterval = setInterval(() => {
+      query.currentRefetchInterval = config.refetchInterval
+      clearInterval(query.refetchIntervalId)
+      query.refetchIntervalId = setInterval(() => {
         if (isDocumentVisible() || config.refetchIntervalInBackground) {
           refetch().catch(Console.error)
         }
       }, config.refetchInterval)
 
       return () => {
-        clearInterval(query.refetchInterval)
-        delete query.refetchInterval
+        clearInterval(query.refetchIntervalId)
+        delete query.refetchIntervalId
+        delete query.currentRefetchInterval
       }
     }
-  }, [
-    config.refetchInterval,
-    config.refetchIntervalInBackground,
-    query.refetchInterval,
-    refetch,
-  ])
+  }, [config.refetchInterval, config.refetchIntervalInBackground, refetch])
 
   return {
     ...query.state,