feat: add poll effect type (#2158)

Author: zhanba

docs/API.md

@@ -343,6 +343,7 @@ type includes:
 * `takeLatest`
 * `throttle`
 * `watcher`
+* `poll`
 
 View https://github.com/dvajs/dva/blob/master/packages/dva-core/test/effects.test.js for details.
 

docs/api/README.md

@@ -339,6 +339,7 @@ type 类型有：
 * `takeLatest`
 * `throttle`
 * `watcher`
+* `poll`
 
 详见：https://github.com/dvajs/dva/blob/master/packages/dva-core/test/effects.test.js
 

packages/dva-core/src/getSaga.js

@@ -23,6 +23,7 @@ function getWatcher(key, _effect, model, onError, onEffect, opts) {
   let effect = _effect;
   let type = 'takeEvery';
   let ms;
+  let delayMs;
 
   if (Array.isArray(_effect)) {
     [effect] = _effect;
@@ -33,10 +34,14 @@ function getWatcher(key, _effect, model, onError, onEffect, opts) {
         invariant(opts.ms, 'app.start: opts.ms should be defined if type is throttle');
         ({ ms } = opts);
       }
+      if (type === 'poll') {
+        invariant(opts.delay, 'app.start: opts.delay should be defined if type is poll');
+        ({ delay: delayMs } = opts);
+      }
     }
     invariant(
-      ['watcher', 'takeEvery', 'takeLatest', 'throttle'].indexOf(type) > -1,
-      'app.start: effect type should be takeEvery, takeLatest, throttle or watcher',
+      ['watcher', 'takeEvery', 'takeLatest', 'throttle', 'poll'].indexOf(type) > -1,
+      'app.start: effect type should be takeEvery, takeLatest, throttle, poll or watcher',
     );
   }
 
@@ -74,6 +79,24 @@ function getWatcher(key, _effect, model, onError, onEffect, opts) {
       return function*() {
         yield sagaEffects.throttle(ms, key, sagaWithOnEffect);
       };
+    case 'poll':
+      return function*() {
+        function delay(timeout) {
+          return new Promise(resolve => setTimeout(resolve, timeout));
+        }
+        function* pollSagaWorker(sagaEffects, action) {
+          const { call } = sagaEffects;
+          while (true) {
+            yield call(sagaWithOnEffect, action);
+            yield call(delay, delayMs);
+          }
+        }
+        const { call, take, race } = sagaEffects;
+        while (true) {
+          const action = yield take(`${key}-start`);
+          yield race([call(pollSagaWorker, sagaEffects, action), take(`${key}-stop`)]);
+        }
+      };
     default:
       return function*() {
         yield sagaEffects.takeEvery(key, sagaWithOnEffect);

packages/dva-core/test/effects.test.js

@@ -414,6 +414,193 @@ describe('effects', () => {
     }, 200);
   });
 
+  it('type: poll', done => {
+    const app = create();
+    app.model({
+      namespace: 'count',
+      state: 0,
+      reducers: {
+        add(state, { payload }) {
+          return state + payload || 1;
+        },
+      },
+      effects: {
+        pollAdd: [
+          function*(_, { put }) {
+            yield put({ type: 'add', payload: 1 });
+          },
+          { type: 'poll', delay: 1000 },
+        ],
+      },
+    });
+    app.start();
+
+    app._store.dispatch({ type: 'count/pollAdd-start' });
+
+    setTimeout(() => {
+      app._store.dispatch({ type: 'count/pollAdd-stop' });
+      expect(app._store.getState().count).toEqual(2);
+      done();
+    }, 2000);
+  });
+
+  it('type: poll and stop', done => {
+    const app = create();
+    app.model({
+      namespace: 'count',
+      state: 0,
+      reducers: {
+        add(state, { payload }) {
+          return state + payload || 1;
+        },
+      },
+      effects: {
+        pollAdd: [
+          function*(_, { put }) {
+            yield put({ type: 'add', payload: 1 });
+          },
+          { type: 'poll', delay: 1000 },
+        ],
+      },
+    });
+    app.start();
+
+    app._store.dispatch({ type: 'count/pollAdd-start' });
+    // should work one time
+    app._store.dispatch({ type: 'count/pollAdd-stop' });
+
+    setTimeout(() => {
+      expect(app._store.getState().count).toEqual(1);
+      done();
+    }, 200);
+  });
+
+  it('type: poll with payload', done => {
+    const app = create();
+    app.model({
+      namespace: 'count',
+      state: 0,
+      reducers: {
+        add(state, { payload }) {
+          return state + payload || 1;
+        },
+      },
+      effects: {
+        pollAdd: [
+          function*({ payload }, { put }) {
+            yield put({ type: 'add', payload });
+          },
+          { type: 'poll', delay: 1000 },
+        ],
+      },
+    });
+    app.start();
+
+    app._store.dispatch({ type: 'count/pollAdd-start', payload: 2 });
+
+    setTimeout(() => {
+      app._store.dispatch({ type: 'count/pollAdd-stop' });
+      expect(app._store.getState().count).toEqual(4);
+      done();
+    }, 2000);
+  });
+
+  it('type: poll, start many time', done => {
+    const app = create();
+    app.model({
+      namespace: 'count',
+      state: 0,
+      reducers: {
+        add(state, { payload }) {
+          return state + payload || 1;
+        },
+      },
+      effects: {
+        pollAdd: [
+          function*({ payload }, { put }) {
+            yield put({ type: 'add', payload });
+          },
+          { type: 'poll', delay: 1000 },
+        ],
+      },
+    });
+    app.start();
+
+    app._store.dispatch({ type: 'count/pollAdd-start', payload: 2 });
+
+    setTimeout(() => {
+      // second start should not work
+      app._store.dispatch({ type: 'count/pollAdd-start', payload: 3 });
+      app._store.dispatch({ type: 'count/pollAdd-stop' });
+      expect(app._store.getState().count).toEqual(6);
+      done();
+    }, 3000);
+  });
+
+  it('type: poll, start many time 2', done => {
+    const app = create();
+    app.model({
+      namespace: 'count',
+      state: 0,
+      reducers: {
+        add(state, { payload }) {
+          return state + payload || 1;
+        },
+      },
+      effects: {
+        pollAdd: [
+          function*(_, { put }) {
+            yield put({ type: 'add', payload: 1 });
+          },
+          { type: 'poll', delay: 1000 },
+        ],
+      },
+    });
+    app.start();
+
+    app._store.dispatch({ type: 'count/pollAdd-start' });
+    // second start should not work
+    app._store.dispatch({ type: 'count/pollAdd-start' });
+
+    setTimeout(() => {
+      app._store.dispatch({ type: 'count/pollAdd-stop' });
+      expect(app._store.getState().count).toEqual(3);
+      done();
+    }, 3000);
+  });
+
+  it('type: poll, start and stop many time', done => {
+    const app = create();
+    app.model({
+      namespace: 'count',
+      state: 0,
+      reducers: {
+        add(state, { payload }) {
+          return state + payload || 1;
+        },
+      },
+      effects: {
+        pollAdd: [
+          function*(_, { put }) {
+            yield put({ type: 'add', payload: 1 });
+          },
+          { type: 'poll', delay: 1000 },
+        ],
+      },
+    });
+    app.start();
+
+    app._store.dispatch({ type: 'count/pollAdd-start' });
+    app._store.dispatch({ type: 'count/pollAdd-stop' });
+    app._store.dispatch({ type: 'count/pollAdd-start' });
+
+    setTimeout(() => {
+      app._store.dispatch({ type: 'count/pollAdd-stop' });
+      expect(app._store.getState().count).toEqual(3);
+      done();
+    }, 2000);
+  });
+
   xit('nonvalid type', () => {
     const app = create();
     app.model({