ui/reducers: convert reducers to typescript

web/src/app/reducers/auth.js → web/src/app/reducers/auth.ts

@@ -1,10 +1,14 @@
 import { AUTH_LOGOUT } from '../actions/auth'
+import { Action, State } from './main'
 
-const initialState = () => ({
+const initialState = (): State => ({
   valid: true,
 })
 
-export default function authReducer(state = initialState(), action) {
+export default function authReducer(
+  state = initialState(),
+  action: Action,
+): State {
   switch (action.type) {
     case AUTH_LOGOUT:
       return { ...state, valid: false }

web/src/app/reducers/index.js → web/src/app/reducers/index.ts

@@ -1,8 +1,8 @@
-import { combineReducers } from 'redux'
+import { combineReducers, Reducer } from 'redux'
 import auth from './auth'
 import main from './main'
 
-export default function createRootReducer() {
+export default function createRootReducer(): Reducer {
   return combineReducers({
     auth, // auth status
     main, // reducer for new user setup flag

web/src/app/reducers/main.js → web/src/app/reducers/main.ts

@@ -1,7 +1,17 @@
 import { SET_SHOW_NEW_USER_FORM } from '../actions'
 import { getParameterByName } from '../util/query_param'
 
-const initialState = {
+export interface State {
+  valid?: boolean
+  isFirstLogin?: boolean
+}
+
+export interface Action {
+  type: string
+  payload?: boolean
+}
+
+const initialState: State = {
   isFirstLogin: getParameterByName('isFirstLogin') === '1',
 }
 
@@ -10,7 +20,10 @@ const initialState = {
  *
  * Returns the immutable final state afterwards (reduce)
  */
-export default function mainReducer(state = initialState, action = {}) {
+export default function mainReducer(
+  state = initialState,
+  action = {} as Action,
+): State {
   switch (action.type) {
     case SET_SHOW_NEW_USER_FORM:
       return {