migrate redux store

Summary: Migrating redux stores to TypeScript

Reviewed By: passy

Differential Revision: D16579796

fbshipit-source-id: e3e507f17f1bdd57eb45e30cb0b28aaee6c4521c

src/reducers/user.tsx

@@ -0,0 +1,51 @@
+/**
+ * Copyright 2018-present Facebook.
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ * @format
+ */
+
+export type User = {
+  name?: string,
+  profile_picture?: {
+    uri: string,
+  },
+};
+
+export type State = User;
+
+export type Action =
+  | {
+      type: 'LOGIN',
+      payload: User,
+    }
+  | {
+      type: 'LOGOUT',
+    };
+
+const INITIAL_STATE: State = {};
+
+export default function reducer(
+  state: State = INITIAL_STATE,
+  action: Action,
+): State {
+  if (action.type === 'LOGOUT') {
+    return {};
+  } else if (action.type === 'LOGIN') {
+    return {
+      ...state,
+      ...action.payload,
+    };
+  } else {
+    return state;
+  }
+}
+
+export const login = (payload: User): Action => ({
+  type: 'LOGIN',
+  payload,
+});
+
+export const logout = (): Action => ({
+  type: 'LOGOUT',
+});