authentication with react-router-redux 5.x and redux-saga https://medium.com/@stepankuzmin/authentication-with-react-router-redux-5-x-and-redux-saga-55da66b54be7

Login.js

import React, { PureComponent } from 'react';
import PropTypes from 'prop-types';
import { connect } from 'react-redux';
import { Redirect } from 'react-router-dom';

import { authorize } from './reducer';
import { tokenSelector, errorSelector } from './selectors';

class Login extends PureComponent {
  constructor(props) {
    super(props);
    this.state = { login: '', password: '' };
    this.onChange = this.onChange.bind(this);
    this.onSubmit = this.onSubmit.bind(this);
  }

  onChange(input, value) {
    this.setState({ [input]: value });
  }

  onSubmit() {
    const { login, password } = this.state;
    this.props.dispatch(authorize(login, password));
  }

  render() {
    const { error, token } = this.props;

    if (token) {
      return <Redirect to="/" />;
    }

    return (
      <div>
        <input
          type='text'
          placeholder='login'      
          value={this.state.login}
          onChange={this.onChange.bind(this, 'login')}
        />
        <input
          type='password'
          placeholder='password'
          value={this.state.password}
          onChange={this.onChange.bind(this, 'password')}
        />
        <button onClick={this.onSubmit}>Submit</button>
      </div>
    );
  }
}

const mapStateToProps = (state) => ({
  token: state.auth.token,
  error: state.auth.error
});

export default connect(mapStateToProps)(Login);