Move left pane entirely to React

ts/state/ducks/user.ts

@@ -0,0 +1,67 @@
+import { LocalizerType } from '../../types/Util';
+
+// State
+
+export type UserStateType = {
+  ourNumber: string;
+  regionCode: string;
+  i18n: LocalizerType;
+};
+
+// Actions
+
+type UserChangedActionType = {
+  type: 'USER_CHANGED';
+  payload: {
+    ourNumber: string;
+    regionCode: string;
+  };
+};
+
+export type UserActionType = UserChangedActionType;
+
+// Action Creators
+
+export const actions = {
+  userChanged,
+};
+
+function userChanged(attributes: {
+  ourNumber: string;
+  regionCode: string;
+}): UserChangedActionType {
+  return {
+    type: 'USER_CHANGED',
+    payload: attributes,
+  };
+}
+
+// Reducer
+
+function getEmptyState(): UserStateType {
+  return {
+    ourNumber: 'missing',
+    regionCode: 'missing',
+    i18n: () => 'missing',
+  };
+}
+
+export function reducer(
+  state: UserStateType,
+  action: UserActionType
+): UserStateType {
+  if (!state) {
+    return getEmptyState();
+  }
+
+  if (action.type === 'USER_CHANGED') {
+    const { payload } = action;
+
+    return {
+      ...state,
+      ...payload,
+    };
+  }
+
+  return state;
+}