3 files changed, 154 insertions, 14 deletions

diff --git a/src/features/utils/ActionBinding.js b/src/features/utils/ActionBinding.js
new file mode 100644
index 000000000..497aa071b
--- /dev/null
+++ b/src/features/utils/ActionBinding.js
@@ -0,0 +1,29 @@
+export default class ActionBinding {
+  action;
+
+  isActive = false;
+
+  constructor(action) {
+    this.action = action;
+  }
+
+  start() {
+    if (!this.isActive) {
+      const { action } = this;
+      action[0].listen(action[1]);
+      this.isActive = true;
+    }
+  }
+
+  stop() {
+    if (this.isActive) {
+      const { action } = this;
+      action[0].off(action[1]);
+      this.isActive = false;
+    }
+  }
+}
+
+export const createActionBindings = actions => (
+  actions.map(a => new ActionBinding(a))
+);
diff --git a/src/features/utils/FeatureStore.js b/src/features/utils/FeatureStore.js
index 66b66a104..0bc10e176 100644
--- a/src/features/utils/FeatureStore.js
+++ b/src/features/utils/FeatureStore.js
@@ -1,21 +1,40 @@
-import Reaction from '../../stores/lib/Reaction';
-
 export class FeatureStore {
-  _actions = null;
+  _actions = [];
+
+  _reactions = [];
+
+  stop() {
+    this._stopActions();
+    this._stopReactions();
+  }
+
+  // ACTIONS
+
+  _registerActions(actions) {
+    this._actions = actions;
+    this._startActions();
+  }
 
-  _reactions = null;
+  _startActions(actions = this._actions) {
+    actions.forEach(a => a.start());
+  }
+
+  _stopActions(actions = this._actions) {
+    actions.forEach(a => a.stop());
+  }
+
+  // REACTIONS
+
+  _registerReactions(reactions) {
+    this._reactions = reactions;
+    this._startReactions();
+  }
 
-  _listenToActions(actions) {
-    if (this._actions) this._actions.forEach(a => a[0].off(a[1]));
-    this._actions = [];
-    actions.forEach(a => this._actions.push(a));
-    this._actions.forEach(a => a[0].listen(a[1]));
+  _startReactions(reactions = this._reactions) {
+    reactions.forEach(r => r.start());
   }
 
-  _startReactions(reactions) {
-    if (this._reactions) this._reactions.forEach(r => r.stop());
-    this._reactions = [];
-    reactions.forEach(r => this._reactions.push(new Reaction(r)));
-    this._reactions.forEach(r => r.start());
+  _stopReactions(reactions = this._reactions) {
+    reactions.forEach(r => r.stop());
   }
 }
diff --git a/src/features/utils/FeatureStore.test.js b/src/features/utils/FeatureStore.test.js
new file mode 100644
index 000000000..92308bf52
--- /dev/null
+++ b/src/features/utils/FeatureStore.test.js
@@ -0,0 +1,92 @@
+import PropTypes from 'prop-types';
+import { observable } from 'mobx';
+import { FeatureStore } from './FeatureStore';
+import { createActionsFromDefinitions } from '../../actions/lib/actions';
+import { createActionBindings } from './ActionBinding';
+import { createReactions } from '../../stores/lib/Reaction';
+
+const actions = createActionsFromDefinitions({
+  countUp: {},
+}, PropTypes.checkPropTypes);
+
+class TestFeatureStore extends FeatureStore {
+  @observable count = 0;
+
+  reactionInvokedCount = 0;
+
+  start() {
+    this._registerActions(createActionBindings([
+      [actions.countUp, this._countUp],
+    ]));
+    this._registerReactions(createReactions([
+      this._countReaction,
+    ]));
+  }
+
+  _countUp = () => {
+    this.count += 1;
+  };
+
+  _countReaction = () => {
+    this.reactionInvokedCount += 1;
+  }
+}
+
+describe('FeatureStore', () => {
+  let store = null;
+
+  beforeEach(() => {
+    store = new TestFeatureStore();
+  });
+
+  describe('registering actions', () => {
+    it('starts the actions', () => {
+      store.start();
+      actions.countUp();
+      expect(store.count).toBe(1);
+    });
+    it('starts the reactions', () => {
+      store.start();
+      actions.countUp();
+      expect(store.reactionInvokedCount).toBe(1);
+    });
+  });
+
+  describe('stopping the store', () => {
+    it('stops the actions', () => {
+      store.start();
+      actions.countUp();
+      store.stop();
+      actions.countUp();
+      expect(store.count).toBe(1);
+    });
+    it('stops the reactions', () => {
+      store.start();
+      actions.countUp();
+      store.stop();
+      store.count += 1;
+      expect(store.reactionInvokedCount).toBe(1);
+    });
+  });
+
+  describe('toggling the store', () => {
+    it('restarts the actions correctly', () => {
+      store.start();
+      actions.countUp();
+      store.stop();
+      actions.countUp();
+      store.start();
+      actions.countUp();
+      expect(store.count).toBe(2);
+    });
+    it('restarts the reactions correctly', () => {
+      store.start();
+      actions.countUp();
+      store.stop();
+      actions.countUp();
+      store.start();
+      actions.countUp();
+      expect(store.count).toBe(2);
+    });
+  });
+});