added infinite scroll async collection bundle

src/__mocks__/MockApiClient.js

@@ -3,6 +3,8 @@ const Items = {
   2: 'Two',
   3: 'Three',
   nilItem: null,
+  collection1: ['one', 'two', 'three'],
+  collection2: ['four', 'five', 'six'],
 }
 
 export default function MockApiClient() {
@@ -18,6 +20,10 @@ export default function MockApiClient() {
       })
     })
 
+  this.resolveAllFetchRequests = async () => {
+    requestQueue.map(r => r.itemId).forEach(itemId => this.resolveFetchRequest(itemId))
+  }
+
   this.resolveFetchRequest = async (itemId, error = null) => {
     const index = requestQueue.findIndex(r => r.itemId === itemId && !r.resolved)
     if (index < 0) {

src/__mocks__/pagingBundle.js

@@ -0,0 +1,15 @@
+export default {
+  name: 'paging',
+  reducer: (state = { currentPage: null, pageSize: 10 }, action) => {
+    if (action.type === 'paging.change') {
+      return {
+        ...state,
+        ...action.payload,
+      }
+    }
+    return state
+  },
+  doChangePaging: payload => ({ type: 'paging.change', payload: payload }),
+  selectCurrentPage: state => state.paging.currentPage,
+  selectPageSize: state => state.paging.pageSize,
+}

src/__mocks__/time.js

@@ -0,0 +1,23 @@
+import timekeeper from 'timekeeper'
+import { tapReactors } from './utils'
+
+export const START_TIME = 1000
+
+export function setUpTimeTravel() {
+  beforeEach(() => timekeeper.freeze(START_TIME))
+
+  afterEach(() => timekeeper.reset())
+}
+
+export function timeTravelTo(time, store) {
+  return new Promise(async (resolve, reject) => {
+    try {
+      timekeeper.travel(START_TIME + time)
+      store.dispatch({ type: 'dummy action', payload: null }) // just tap the app time
+      await tapReactors()
+      resolve()
+    } catch (e) {
+      reject(e)
+    }
+  })
+}

src/__mocks__/utils.js

@@ -0,0 +1,6 @@
+export async function tapReactors() {
+  const tapOneReactor = () => new Promise(resolve => setTimeout(resolve, 0))
+  await tapOneReactor()
+  await tapOneReactor()
+  await tapOneReactor()
+}

src/__test_behaviors__/behavesAsResourceWithDependencies.js

@@ -0,0 +1,105 @@
+import { tapReactors } from '../__mocks__/utils'
+
+export default function behavesAsStalingResource(
+  { selectors, actionCreators },
+  { fetchActionCreator, fetchPendingSelector, createStore }
+) {
+  const isPendingForFetch = store => store[fetchPendingSelector]()
+  const isStale = store => store[selectors.isStale]()
+  const isPresent = store => store[selectors.isPresent]()
+  const triggerFetch = store => store[fetchActionCreator]()
+
+  describe('dependency keys', () => {
+    describe('with one dependency', () => {
+      test('does not try to fetch while dependencies are not satisfied', () => {
+        const { store } = createStore({ dependencyKey: 'currentPage' })
+        expect(isPendingForFetch(store)).toBe(false)
+      })
+
+      test('triggers pending state as soon as dependency is resolved', async () => {
+        const { store } = createStore({ dependencyKey: 'currentPage' })
+        store.doChangePaging({ currentPage: 1 })
+        await tapReactors()
+        expect(isPendingForFetch(store)).toBe(true)
+      })
+
+      test('clears the store when dependency changes', async () => {
+        const { store, apiMock } = createStore({ dependencyKey: 'currentPage' })
+        store.doChangePaging({ currentPage: 1 })
+        await tapReactors()
+        triggerFetch(store)
+        await apiMock.resolveAllFetchRequests()
+
+        store.doChangePaging({ currentPage: 2 })
+        await tapReactors()
+        expect(isPresent(store)).toBe(false)
+      })
+
+      test('stales a resource instead of clearing it with "stale" option', async () => {
+        const { store, apiMock } = createStore({ dependencyKey: { key: 'currentPage', staleOnChange: true } })
+        store.doChangePaging({ currentPage: 1 })
+        await tapReactors()
+        triggerFetch(store)
+        await apiMock.resolveAllFetchRequests()
+
+        store.doChangePaging({ currentPage: 2 })
+        await tapReactors()
+
+        expect(isPresent(store)).toBe(true)
+        expect(isStale(store)).toBe(true)
+      })
+
+      test('allows to enable passing down blank values', async () => {
+        const { store } = createStore({ dependencyKey: { key: 'currentPage', allowBlank: true } })
+        await tapReactors()
+        expect(isPendingForFetch(store)).toBe(true)
+      })
+
+      test.todo('mixes in dependency values into getPromise call')
+    })
+
+    describe('with multiple dependencies', () => {
+      test('does not try to fetch while dependencies are not satisfied', () => {
+        const { store } = createStore({ dependencyKey: ['currentPage', 'pageSize'] })
+        expect(isPendingForFetch(store)).toBe(false)
+      })
+
+      test('triggers pending state as soon as dependency is resolved', async () => {
+        const { store } = createStore({ dependencyKey: ['currentPage', 'pageSize'] })
+        store.doChangePaging({ currentPage: 1 })
+        await tapReactors()
+        await tapReactors()
+        expect(isPendingForFetch(store)).toBe(true)
+      })
+
+      test('clears the store when dependency changes', async () => {
+        const { store, apiMock } = createStore({ dependencyKey: ['currentPage', 'pageSize'] })
+        store.doChangePaging({ currentPage: 1 })
+        await tapReactors()
+        await tapReactors()
+
+        triggerFetch(store)
+        await apiMock.resolveAllFetchRequests()
+
+        store.doChangePaging({ currentPage: 2 })
+        await tapReactors()
+        expect(isPresent(store)).toBe(false)
+      })
+
+      test('stales a resource instead of clearing it with "stale" option and allows blank items', async () => {
+        const { store } = createStore({
+          dependencyKey: [{ key: 'currentPage', allowBlank: true }, { key: 'pageSize', staleOnChange: true }],
+        })
+
+        await tapReactors()
+        expect(isPendingForFetch(store)).toBe(true)
+
+        store.doChangePaging({ pageSize: 120 })
+        await tapReactors()
+        expect(isStale(store)).toBe(true)
+      })
+
+      test.todo('mixes in dependency values into getPromise call')
+    })
+  })
+}

src/__test_behaviors__/behavesAsStalingResource.js

@@ -0,0 +1,37 @@
+import { timeTravelTo } from '../__mocks__/time'
+
+export default function behavesAsStalingResource({ selectors, actionCreators }, { fetchActionCreator, createStore }) {
+  describe('staling feature', () => {
+    test('marks item as stale manually', async () => {
+      const { store, apiMock } = createStore({ staleAfter: 15 })
+
+      store[fetchActionCreator]()
+
+      await apiMock.resolveAllFetchRequests()
+
+      store[actionCreators.doMarkAsStale]()
+
+      expect(store[selectors.isPresent]()).toBe(true)
+      expect(store[selectors.isStale]()).toBe(true)
+
+      await timeTravelTo(16, store)
+
+      expect(store[selectors.isPresent]()).toBe(true)
+      expect(store[selectors.isStale]()).toBe(true)
+    })
+
+    test('marks item as stale with a timer', async () => {
+      const { store, apiMock } = createStore({ staleAfter: 15 })
+
+      store[fetchActionCreator]()
+
+      await apiMock.resolveAllFetchRequests()
+
+      expect(store[selectors.isStale]()).toBe(false)
+
+      await timeTravelTo(16, store)
+
+      expect(store[selectors.isStale]()).toBe(true)
+    })
+  })
+}