AdForm.jsx

import React, {PropTypes} from 'react';
import {Form} from 'semantic-ui-react';
import I18n from '../../helpers/I18n';

const AdForm = ({ad, onChange}) => {
    return (
        <Form>
            <h1>{i18n.ad.new}</h1>

            <Form.Input
                name="title"
                label={i18n.ad.form.title}
                value={ad.title}
            />

            <Form.TextArea
                name="txt"
                label={i18n.ad.form.txt}
                onChange={onChange}
                value={ad.txt}
            />

            <Form.Button type="submit">
                {i18n.common.form.save}
            </Form.Button>

        </Form>
    );
};

AdForm.propTypes = {
    ad: PropTypes.object.isRequired,
    onChange: PropTypes.func.isRequired
};

export default AdForm;

ManageAdPage.jsx

import React, {PropTypes} from 'react';
import {connect} from 'react-redux';
import {bindActionCreators} from 'redux';
import * as adActions from '../../actions/adActions';
import AdForm from './AdForm';

export class ManageAdPage extends React.Component
{
    constructor(props, context) {
        super(props, context);

        this.state = {
            ad: Object.assign({}, props.ad),
            errors: {}
        };

        this.updateAdState = this.updateAdState.bind(this);
    }

    updateAdState(event) {
        const field = event.target.name;
        let ad = this.state.ad;
        ad[field] = event.target.value;

        return this.setState({ad: ad});
    }

    render() {
        return (
            <AdForm
                ad={this.state.ad}
                onChange={this.updateAdState}
            />
        );
    }
}

ManageAdPage.propTypes = {
    ad: PropTypes.object.isRequired,
    actions: PropTypes.object.isRequired
};

function mapStateToProps(state, ownProps) {
    const slug = ownProps.params.slug;

    let ad = {
        _id: '', slug: '', txt: ''
    };

    if (slug && state.ads.length > 0) {
        //ad = getAdBySlug(state.ads, slug);
    }

    return {
        ad: ad
    };
}

function mapDispatchToProps(dispatch) {
    return {
        actions: bindActionCreators(adActions, dispatch)
    };
}

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

ManageAdPage.spec.jsx

import React from 'react';
import {mount} from 'enzyme';
import expect from 'expect';
import {ManageAdPage} from '../../../src/components/ad/ManageAdPage';

function setup() {
    const props = {
        actions: {},
        ad: {
            _id: '', txt: ''
        }
    };

    return mount(<ManageAdPage {...props}/>);
}

describe('Form Behavior', () => {
    let wrapper;

    beforeEach(() => {
        wrapper = setup();
    });

    it('shows that text is entered into text textarea', () => {
        const txtTextArea = wrapper.find('FormTextArea');
        txtTextArea.simulate('change', 'text goes here');
//console.log(txtTextArea.props());
        expect(txtTextArea.props().value).toEqual('text goes here');
    });
});