7 files changed, 86 insertions, 23 deletions
diff --git a/src/content/reducers/addon.ts b/src/content/reducers/addon.ts
index 0def55a..2131228 100644
--- a/src/content/reducers/addon.ts
+++ b/src/content/reducers/addon.ts
@@ -1,10 +1,17 @@
-import actions from 'content/actions';
+import * as actions from '../actions';
 
-const defaultState = {
+export interface State {
+  enabled: boolean;
+}
+
+const defaultState: State = {
   enabled: true,
 };
 
-export default function reducer(state = defaultState, action = {}) {
+export default function reducer(
+  state: State = defaultState,
+  action: actions.AddonAction,
+): State {
   switch (action.type) {
   case actions.ADDON_SET_ENABLED:
     return { ...state,
diff --git a/src/content/reducers/find.ts b/src/content/reducers/find.ts
index 4560e2c..8c3e637 100644
--- a/src/content/reducers/find.ts
+++ b/src/content/reducers/find.ts
@@ -1,11 +1,19 @@
-import actions from 'content/actions';
+import * as actions from '../actions';
 
-const defaultState = {
+export interface State {
+  keyword: string | null;
+  found: boolean;
+}
+
+const defaultState: State = {
   keyword: null,
   found: false,
 };
 
-export default function reducer(state = defaultState, action = {}) {
+export default function reducer(
+  state: State = defaultState,
+  action: actions.FindAction,
+): State {
   switch (action.type) {
   case actions.FIND_SET_KEYWORD:
     return { ...state,
diff --git a/src/content/reducers/follow-controller.ts b/src/content/reducers/follow-controller.ts
index 5869c47..6965704 100644
--- a/src/content/reducers/follow-controller.ts
+++ b/src/content/reducers/follow-controller.ts
@@ -1,13 +1,23 @@
-import actions from 'content/actions';
+import * as actions from '../actions';
 
-const defaultState = {
+export interface State {
+  enabled: boolean;
+  newTab: boolean;
+  background: boolean;
+  keys: string,
+}
+
+const defaultState: State = {
   enabled: false,
   newTab: false,
   background: false,
   keys: '',
 };
 
-export default function reducer(state = defaultState, action = {}) {
+export default function reducer(
+  state: State = defaultState,
+  action: actions.FollowAction,
+): State {
   switch (action.type) {
   case actions.FOLLOW_CONTROLLER_ENABLE:
     return { ...state,
diff --git a/src/content/reducers/index.ts b/src/content/reducers/index.ts
index bf612a3..fb5eb84 100644
--- a/src/content/reducers/index.ts
+++ b/src/content/reducers/index.ts
@@ -1,10 +1,20 @@
 import { combineReducers } from 'redux';
-import addon from './addon';
-import find from './find';
-import setting from './setting';
-import input from './input';
-import followController from './follow-controller';
-import mark from './mark';
+import addon, { State as AddonState } from './addon';
+import find, { State as FindState } from './find';
+import setting, { State as SettingState } from './setting';
+import input, { State as InputState } from './input';
+import followController, { State as FollowControllerState }
+  from './follow-controller';
+import mark, { State as MarkState } from './mark';
+
+export interface State {
+  addon: AddonState;
+  find: FindState;
+  setting: SettingState;
+  input: InputState;
+  followController: FollowControllerState;
+  mark: MarkState;
+}
 
 export default combineReducers({
   addon, find, setting, input, followController, mark,
diff --git a/src/content/reducers/input.ts b/src/content/reducers/input.ts
index 23e7dd2..6257e49 100644
--- a/src/content/reducers/input.ts
+++ b/src/content/reducers/input.ts
@@ -1,10 +1,17 @@
-import actions from 'content/actions';
+import * as actions from '../actions';
 
-const defaultState = {
+export interface State {
+  keys: string[];
+}
+
+const defaultState: State = {
   keys: []
 };
 
-export default function reducer(state = defaultState, action = {}) {
+export default function reducer(
+  state: State = defaultState,
+  action: actions.InputAction,
+): State {
   switch (action.type) {
   case actions.INPUT_KEY_PRESS:
     return { ...state,
diff --git a/src/content/reducers/mark.ts b/src/content/reducers/mark.ts
index 2c96cc5..e78b7b9 100644
--- a/src/content/reducers/mark.ts
+++ b/src/content/reducers/mark.ts
@@ -1,12 +1,26 @@
-import actions from 'content/actions';
+import * as actions from '../actions';
 
-const defaultState = {
+interface Mark {
+  x: number;
+  y: number;
+}
+
+export interface State {
+  setMode: boolean;
+  jumpMode: boolean;
+  marks: { [key: string]: Mark };
+}
+
+const defaultState: State = {
   setMode: false,
   jumpMode: false,
   marks: {},
 };
 
-export default function reducer(state = defaultState, action = {}) {
+export default function reducer(
+  state: State = defaultState,
+  action: actions.MarkAction,
+): State {
   switch (action.type) {
   case actions.MARK_START_SET:
     return { ...state, setMode: true };
diff --git a/src/content/reducers/setting.ts b/src/content/reducers/setting.ts
index a49db6d..fa8e8ee 100644
--- a/src/content/reducers/setting.ts
+++ b/src/content/reducers/setting.ts
@@ -1,11 +1,18 @@
-import actions from 'content/actions';
+import * as actions from '../actions';
+
+export interface State {
+  keymaps: any[];
+}
 
 const defaultState = {
   // keymaps is and arrays of key-binding pairs, which is entries of Map
   keymaps: [],
 };
 
-export default function reducer(state = defaultState, action = {}) {
+export default function reducer(
+  state: State = defaultState,
+  action: actions.SettingAction,
+): State {
   switch (action.type) {
   case actions.SETTING_SET:
     return { ...action.value };