Replace solution with state marker check and streamline test

.vscode/settings.json

@@ -1,8 +1,19 @@
 {
   "workbench.colorCustomizations": {
-    "titleBar.activeBackground": "#ff4154", // change this color!
-    "titleBar.inactiveBackground": "#ff4154", // change this color!
-    "titleBar.activeForeground": "#ffffff", // change this color!
-    "titleBar.inactiveForeground": "#ffffff" // change this color!
-  }
+    "activityBar.background": "#ff7482",
+    "activityBar.activeBackground": "#ff7482",
+    "activityBar.activeBorder": "#70ff60",
+    "activityBar.foreground": "#15202b",
+    "activityBar.inactiveForeground": "#15202b99",
+    "activityBarBadge.background": "#70ff60",
+    "activityBarBadge.foreground": "#15202b",
+    "titleBar.activeBackground": "#ff4154",
+    "titleBar.inactiveBackground": "#ff415499",
+    "titleBar.activeForeground": "#e7e7e7",
+    "titleBar.inactiveForeground": "#e7e7e799",
+    "statusBar.background": "#ff4154",
+    "statusBarItem.hoverBackground": "#ff7482",
+    "statusBar.foreground": "#e7e7e7"
+  },
+  "peacock.color": "#ff4154"
 }

src/queryCache.js

@@ -17,6 +17,7 @@ export const queryCache = makeQueryCache()
 const actionInit = {}
 const actionFailed = {}
 const actionMarkStale = {}
+const actionMarkGC = {}
 const actionFetch = {}
 const actionSuccess = {}
 const actionError = {}
@@ -238,11 +239,11 @@ export function makeQueryCache() {
     }
 
     query.scheduleGarbageCollection = () => {
-      const scheduledAt = Date.now()
+      dispatch({ type: actionMarkGC })
       query.cacheTimeout = setTimeout(
         () => {
           cache.removeQueries(
-            d => d.state.updatedAt < scheduledAt && d.queryHash === query.queryHash
+            d => d.state.markedForGarbageCollection && d.queryHash === query.queryHash
           )
         },
         typeof query.state.data === 'undefined' &&
@@ -450,6 +451,7 @@ export function defaultQueryReducer(state, action) {
         canFetchMore: false,
         failureCount: 0,
         isStale: action.isStale,
+        markedForGarbageCollection: false,
         data: action.initialData,
         updatedAt: action.hasInitialData ? Date.now() : 0,
       }
@@ -463,6 +465,12 @@ export function defaultQueryReducer(state, action) {
         ...state,
         isStale: true,
       }
+    case actionMarkGC: {
+      return {
+        ...state,
+        markedForGarbageCollection: true,
+      }
+    }
     case actionFetch:
       return {
         ...state,

src/tests/queryCache.test.js

@@ -143,4 +143,34 @@ describe('queryCache', () => {
     await sleep(50)
     expect(query.state.isStale).toBe(false)
   })
+
+  test('query is garbage collected when unsubscribed to', async () => {
+    const queryKey = 'key'
+    const fetchData = () => Promise.resolve('data')
+    await queryCache.prefetchQuery(queryKey, fetchData, { cacheTime: 0 })
+    const query = queryCache.getQuery(queryKey)
+    expect(query.state.markedForGarbageCollection).toBe(false)
+    const unsubscribe = query.subscribe(1)
+    unsubscribe()
+    expect(query.state.markedForGarbageCollection).toBe(true)
+    await sleep(1)
+    expect(queryCache.getQuery(queryKey)).toBeUndefined()
+  })
+
+  test('query is not garbage collected unless markedForGarbageCollection is true', async () => {
+    const queryKey = 'key'
+    const fetchData = () => Promise.resolve(undefined)
+    await queryCache.prefetchQuery(queryKey, fetchData, { cacheTime: 0 })
+    const query = queryCache.getQuery(queryKey)
+    expect(query.state.markedForGarbageCollection).toBe(false)
+    const unsubscribe = query.subscribe(1)
+    unsubscribe()
+    expect(query.state.markedForGarbageCollection).toBe(true)
+    queryCache.clear()
+    queryCache.setQueryData(queryKey, 'data')
+    await sleep(1)
+    const newQuery = queryCache.getQuery(queryKey)
+    expect(newQuery.state.markedForGarbageCollection).toBe(false)
+    expect(newQuery.state.data).toBe('data')
+  })
 })