feat(redux): update to redux v4 (#501)

BREAKING CHANGE: redux-observable now requires redux v4. The new version of redux is mostly the same, however it required us to change the `createEpicMiddleware` API. See https://redux-observable.js.org/MIGRATION.html

package.json

@@ -64,7 +64,7 @@
   },
   "homepage": "https://github.com/redux-observable/redux-observable#README.md",
   "peerDependencies": {
-    "redux": ">=3 <4",
+    "redux": ">=4 <5",
     "rxjs": ">=6.0.0-beta.0 <7"
   },
   "devDependencies": {
@@ -95,7 +95,7 @@
     "gulp-babel": "^6.1.2",
     "json-server": "^0.10.0",
     "mocha": "^3.5.3",
-    "redux": "^3.5.2",
+    "redux": "^4.0.0",
     "rimraf": "^2.5.4",
     "rxjs": "^6.0.0",
     "sinon": "^4.5.0",

test/createEpicMiddleware-spec.js

@@ -7,6 +7,7 @@ import { createEpicMiddleware, combineEpics, ActionsObservable, StateObservable,
 import { resetDeprecationsSeen } from '../lib/cjs/utils/console';
 import { of, empty, merge } from 'rxjs';
 import { mapTo, filter, map, mergeMap, startWith, ignoreElements, distinctUntilChanged } from 'rxjs/operators';
+import { initAction } from './initAction';
 
 describe('createEpicMiddleware', () => {
   let spySandbox;
@@ -103,9 +104,7 @@ describe('createEpicMiddleware', () => {
     store.dispatch({ type: 'PING' });
 
     expect(store.getState()).to.equal(2);
-    expect(actions).to.deep.equal([{
-      type: '@@redux/INIT'
-    }, {
+    expect(actions).to.deep.equal([initAction, {
       type: 'PING'
     }, {
       type: 'PONG',
@@ -167,9 +166,7 @@ describe('createEpicMiddleware', () => {
     store.dispatch({ type: 'FIRST' });
 
     expect(store.getState().value).to.equal(8);
-    expect(actions).to.deep.equal([{
-      type: '@@redux/INIT'
-    }, {
+    expect(actions).to.deep.equal([initAction, {
       type: 'FIRST'
     }, {
       type: 'STATE',
@@ -209,9 +206,7 @@ describe('createEpicMiddleware', () => {
 
     expect(console.warn.callCount).to.equal(1);
     expect(console.warn.getCall(0).args[0]).to.equal('redux-observable | WARNING: You accessed state$.value inside one of your Epics, before your reducers have run for the first time, so there is no state yet. You\'ll need to wait until after the first action (@@redux/INIT) is dispatched or by using state$ as an Observable.');
-    expect(store.getState()).to.deep.equal([{
-      type: '@@redux/INIT'
-    }, {
+    expect(store.getState()).to.deep.equal([initAction, {
       type: 'PONG',
       state: undefined
     }, {
@@ -268,7 +263,7 @@ describe('createEpicMiddleware', () => {
     store.dispatch({ type: 'FIRE_2' });
 
     expect(store.getState()).to.deep.equal([
-      { type: '@@redux/INIT' },
+      initAction,
       { type: 'FIRE_1' },
       { type: 'ACTION_1' },
       { type: 'FIRE_2' },
@@ -291,7 +286,7 @@ describe('createEpicMiddleware', () => {
     middleware.run(rootEpic);
 
     expect(store.getState()).to.deep.equal([
-      { type: '@@redux/INIT' },
+      initAction,
       { type: 'ACTION_1' },
       { type: 'ACTION_2' }
     ]);
@@ -321,7 +316,7 @@ describe('createEpicMiddleware', () => {
     middleware.run(rootEpic);
 
     expect(store.getState()).to.deep.equal([
-      { type: '@@redux/INIT' },
+      initAction,
       { type: 'ACTION_1' },
       { type: 'ACTION_2' },
       { type: 'ACTION_3' },
@@ -394,7 +389,7 @@ describe('createEpicMiddleware', () => {
     middleware.run(epic);
 
     expect(store.getState()).to.deep.equal([
-      { type: '@@redux/INIT' },
+      initAction,
       { type: 3 }
     ]);
   });

test/initAction.d.ts

@@ -0,0 +1 @@
+export const initAction: { type: string };

test/initAction.js

@@ -0,0 +1,3 @@
+import { __DO_NOT_USE__ActionTypes as actionTypes } from 'redux';
+
+export const initAction = { type: actionTypes.INIT };

test/typings.ts

@@ -6,6 +6,7 @@ import { map, mapTo, mergeMap } from 'rxjs/operators';
 
 import { createEpicMiddleware, Epic, combineEpics,
   EpicMiddleware, ActionsObservable, StateObservable, ofType } from '../';
+import { initAction } from './initAction';
 
 interface State {
   foo: string
@@ -170,27 +171,27 @@ store.dispatch({ type: 'EIGHTH', payload: 'eighth-payload' });
 store.dispatch({ type: 'NINTH', payload: 'ninth-payload' });
 
 expect(store.getState()).to.deep.equal([
-  { "type": "@@redux/INIT" },
+  initAction,
   { "type": "fourth" },
   { "type": "fourth" },
   { "type": "FIRST" },
   { "type": "first",
     "payload": [
-      { "type": "@@redux/INIT" },
+      initAction,
       { "type": "fourth" },
       { "type": "fourth" },
       { "type": "FIRST" }
     ]
   },
   { "type": "first",
     "payload": [
-      { "type": "@@redux/INIT" },
+      initAction,
       { "type": "fourth" },
       { "type": "fourth" },
       { "type": "FIRST" },
       { "type": "first",
         "payload": [
-          { "type": "@@redux/INIT" },
+          initAction,
           { "type": "fourth" },
           { "type": "fourth" },
           { "type": "FIRST" }