move store to shared

src/shared/store/index.js

@@ -0,0 +1,53 @@
+class Store {
+  constructor(reducer, catcher) {
+    this.reducer = reducer;
+    this.catcher = catcher;
+    this.subscribers = [];
+    try {
+      this.state = this.reducer(undefined, {});
+    } catch (e) {
+      catcher(e);
+    }
+  }
+
+  dispatch(action, sender) {
+    if (action instanceof Promise) {
+      action.then((a) => {
+        this.transitNext(a, sender);
+      }).catch((e) => {
+        this.catcher(e, sender);
+      });
+    } else {
+      try {
+        this.transitNext(action, sender);
+      } catch (e) {
+        this.catcher(e, sender);
+      }
+    }
+    return action;
+  }
+
+  getState() {
+    return this.state;
+  }
+
+  subscribe(callback) {
+    this.subscribers.push(callback);
+  }
+
+  transitNext(action, sender) {
+    let newState = this.reducer(this.state, action);
+    if (JSON.stringify(this.state) !== JSON.stringify(newState)) {
+      this.state = newState;
+      this.subscribers.forEach(f => f(sender));
+    }
+  }
+}
+
+const empty = () => {};
+
+const createStore = (reducer, catcher = empty) => {
+  return new Store(reducer, catcher);
+};
+
+export { createStore };