Getting a "Uncaught ReferenceError: type is not defined" error in React / Redux?

Question

I'm making a very simple ToDo list with Redux and React. I'm getting a "Uncaught ReferenceError: type is not defined" when trying to add a todo item. I have tried several things, here is my current code. Any ideas what I'm doing wrong? Thank you!

Here is my container:

import React, {Component} from 'react';
import { connect } from 'react-redux';
import { bindActionCreators } from 'redux';
import { addTodo } from '../actions/index';

class Todos extends Component {
    constructor(props) {
        super(props);
        this.state = {text: ''};
    }

    addTodo(e) {
        e.preventDefault();
        this.props.addTodo(this.state.text);
        this.setState({
            text: ''
        });
    }

    updateValue(e) {
        this.setState({text: e.target.value})
    }

    render() {
        return (
            <div>
                <form onSubmit={(e) => this.addTodo(e)}>
                    <input
                        placeholder="Add Todo"
                        value={this.state.text}
                        onChange={(e) => {
                            this.updateValue(e)
                        }}
                    />
                    <button type="submit">Add Todo</button>
                </form>
                <ul>
                    { this.props.todo.map((item) => {
                        return <li key={item.id}>{ item.message }</li>
                    })}
                </ul>
            </div>
        );
    }
}

function mapStateToProps({ todo }) {
    return { todo }
}

function mapDispatchToProps(dispatch) {
    return bindActionCreators({addTodo}, dispatch);
}

export default connect(mapStateToProps, mapDispatchToProps)(Todos);

Here is the reducer:

import { ADD_TODO } from '../actions/types';

export default function(state=[], action) {
    switch(action.type) {
        case ADD_TODO:
            return [ action.payload.message, ...state ]
    }
    return state;
}

And ../reducers/index.js

import { combineReducers } from 'redux';
import TodosReducer from './reducer_addTodo';

const rootReducer = combineReducers({
    todo: TodosReducer
});

export default rootReducer;

And the action:

import { ADD_TODO } from './types';
const uid = () => Math.random().toString(34).slice(2);

export function addTodo(message) {
    const action = {
        id: uid(),
        message: message
    };
    return(
        type: ADD_TODO,
        payload: action
    )
}

When trying to add a Todo item, I get the following error:

Uncaught ReferenceError: type is not defined
    at addTodo (bundle.js:21950)
    at Object.addTodo (bundle.js:21166)
    at Todos.addTodo (bundle.js:23541)
    at onSubmit (bundle.js:23562)
    at Object.ReactErrorUtils.invokeGuardedCallback (bundle.js:4532)
    at executeDispatch (bundle.js:4332)
    at Object.executeDispatchesInOrder (bundle.js:4355)
    at executeDispatchesAndRelease (bundle.js:3785)
    at executeDispatchesAndReleaseTopLevel (bundle.js:3796)
    at Array.forEach (<anonymous>)

EDIT:

Here is the types.js file:

export const ADD_TODO = 'ADD_TODO';

Answer 1

what you only need to change to make it perfectly work, simply change:

return { 
    type: 'ADD_TODO', //this is string 
    payload: action
};

Answer 2

I think the main reason of the error is due to a typo in your addTodo function. Replace the parenthesis with curly braces

export function addTodo(message) {
    const action = {
        id: uid(),
        message: message
    };
    return {
        type: ADD_TODO,
        payload: action
    };
}