Unable to change the value of form inputs

[MoonTahoe]

First... let me mention that I love using enzyme. Great work. I am currently putting togther training materials for React that will use enzyme for testing.

Problem

I am having a problem testing a form. Specifically changing input values on the form.

wrapper.ref('first').simulate('change', {target: {value: 'David'}}); is not working
wrapper.find("input#first").simulate('change', {target: {value: 'David'}}); is not working

I have created a reduced test case that demonstrates the problem. The output for this example looks like:

Output

  Testing a form
first name: Mike
last name: Tyson
    ✓ can fill out the form

No matter what the default Mike Tyson is always the name, despite the fact that I am chanign it. Why does this happen? Is there another way to change the values for the form?

Test

import { Component } from 'react'
import { expect } from 'chai'
import { mount } from 'enzyme'

class TheForm extends Component {

    submit() {
        console.log('first name:', this.refs.first.value);
        console.log('last name:', this.refs.last.value);
    }

    render() {
        return (
            <form action="javascript:void(0)"
                  onSubmit={this.submit.bind(this)}>

                <div>
                    <input ref="first"
                           type="text"
                           placeholder="your first name..."
                           required="required"
                           defaultValue="Mike"/>
                </div>

                <div>
                    <input ref="last"
                           type="text"
                           placeholder="your last name..."
                           required="required"
                           defaultValue="Tyson" />
                </div>

                <button>ADD</button>

            </form>
        );
    }

}

describe("Testing a form", () => {

    it("can fill out the form", () => {
        const wrapper = mount(<TheForm />);
        wrapper.ref('first').simulate('change', {target: {value: 'David'}});
        wrapper.ref('last').simulate('change', {target: {value: 'Blane'}});
        wrapper.find('form').simulate('submit');
    });

});

also... wrapper.find('form').simulate('submit') works, but clicking the button does not. Even though clicking the button submits the form in the browser.

[aweary]

also... wrapper.find('form').simulate('submit') works, but clicking the button does not. Even though clicking the button submits the form in the browser.

FYI this has been reported previously here: #308

[aweary]

I'm able to reproduce your issue with the current release of enzyme, I'll look into how this is expected to work. For what it's worth, you can use controlled components to handle the input state, which works as you expected:

class TheForm extends React.Component {

    constructor(props) {
      super(props);
      this.state = {
        firstName: 'Mike',
        lastName: 'Tyson'
      }
      this.onFirstNameChange = this.onFirstNameChange.bind(this);
      this.onLastNameChange = this.onLastNameChange.bind(this);
    }

    submit() {
        console.log('first name:', this.state.firstName);
        console.log('last name:', this.state.lastName);
    }

    onFirstNameChange(e) {
      this.setState({
        firstName: e.target.value
      })
    }

    onLastNameChange(e) {
      this.setState({
        lastName: e.target.value
      })
    }

    render() {
        return (
            <form action="javascript:void(0)"
                  onSubmit={this.submit.bind(this)}>

                <div>
                    <input ref="first"
                           type="text"
                           placeholder="your first name..."
                           required="required"
                           onChange={this.onFirstNameChange}
                           value={this.state.firstName}/>
                </div>

                <div>
                    <input ref="last"
                           type="text"
                           placeholder="your last name..."
                           required="required"
                           onChange={this.onLastNameChange}
                           value={this.state.lastName} />
                </div>

                <button>ADD</button>

            </form>
        );
    }

}

Controlled components are typically recommended as well: https://facebook.github.io/react/docs/forms.html

[MoonTahoe]

Yea, thanks. The issue, in my case is that I cannot change the TheForm, I only have access to the test for the form.

[MoonTahoe]

I was able to create a test that passed based on what I found in issue #76.

describe("Testing a form", () => {

    let wrapper;

    before(() => {
        wrapper = mount(<TheForm />);
        wrapper.ref('first').get(0).value = 'David';
        wrapper.ref('last').get(0).value = 'Blane';
        wrapper.find('form').simulate('submit');
    });

    it("can set first name", () => expect(wrapper.ref('first').get(0).value).to.equal("David"));

    it("can set last name", () => expect(wrapper.ref('last').get(0).value).to.equal("Blane"));

});

It would be nice if there were a cleaner way to do this as requested in Issue #76

[aweary]

@MoonTahoe I'm curious, does this work?

wrapper.find('input').first().simulate('change', {target: {value: 'David'}});`

[aweary]

@MoonTahoe also, following the example of ReactTestUtils.Simulate.change, this should work:

const wrapper = mount(<TheForm/>);
const first = wrapper.find('first');
first.node.value = 'David'
first.simulate('change', first)

[ffxsam]

I also ran into issues getting and setting values on <input /> tags. input.node.value works great, but I'm curious why this doesn't work:

    const wrapper = mount(<EditableText defaultValue="Hello" />);
    const input = wrapper.find('input');

    console.log(input.render().val());

https://stackoverflow.com/questions/37219772/enzyme-how-to-access-and-set-input-value

[tarjei]

Hi, I'm sorry for hijacking this thread, but the examples listed here should go into the documentation. Form handling is badly documented (IMHO).

Also, how about a setValue(value, triggerChange=true) method that could work on select and input? I.e. you could use the method to both set a value and emit the change event. this would improve usability for formhandling a lot.

Then you can do wrapper.find('input').setValue("val") instead of a three line bolierplate invocation.

T

[ghost]

using the solution proposed by @aweary, I get TypeError: Can't add property value, object is not extensible

[aweary]

@Moezalez what testing environment are you using (jsdom, karma, etc.)?

[ghost]

@aweary nyc + mocha

[aweary]

@Moezalez so you're using jsdom? What version of React and what version of enzyme? Can you share a small reproducable case?

[whitejava]

This works fine for me:

// <div><input/></div>
let a = mount(<TestComponent/>);
a.find('input').node.value = 'Task1';

[bchenSyd]

just to help people who are struggling with changing input value (and do some further checks, like validation). here is something that works for me after I read through this post

 it('should display business trade name correctly', () => {
        const business_trade_name = wrapper.findWhere(n => n.name() === 'Field'
            && n.prop('name') === 'business_trade_name')
        expect(business_trade_name).toExist('cannot find business_trade_name. did you accidently renamed the field?')


        const input = business_trade_name.find('input')

        input.node.value='bo chen**&&))'
        input.simulate('change', input)

        wrapper.find('form').simulate('submit')

       const errorSpan = business_trade_name.find('span')
       expect(errorSpan.text()).toBe('Invalid business trade name')


    })

my rendered dom tree is like

<form>
       <Field name='business_trade_name'>
           <input />
          <span />
      </Field>

      <Field name='another_field'>
         <input />
        <span />
      </Field>
</form>

and yes, i'm using redux-form

[julia-kits]

@bochen2014 thanks so much, your solution is the only one working for me! you really helped me!

[erika-dike]

@bochen2014 another +1 for you. Thanks a lot. Your solution alone worked for me.

[Rob-Leggett]

The following worked for me also.

const username = wrapper.ref('username')
username.node.value='test'
username.simulate('change', username)

However I am disappointed the following did not work.

wrapper.ref('username').simulate('change', {target: {value: 'test'}})

[ConAntonakos]

@aweary's solution worked for my testing purposes, yet I still don't know why. 😉

[nerfologist]

Hi, I opened PR #995 adding a test case to (hopefully) demonstrate this issue.

[Falieson]

I also am getting errors related to this subject (simulate('change' ...) not causing a change)

test('TaskHeader changes Value after Inputted', () => {
  const component = mount(<TaskHeader listName="Demo" totalTasks={55} />)

  const taskInput = component.find('.app-tasks-newTask-input')
  expect(taskInput.props().value).toEqual('')

  // const event =  { target: { value: 'First Task' } }
  
  taskInput.props().onChange({currentTarget: {value: 'First Task'}}) // NOTE: this works
  expect(taskInput.props().value).toEqual('First Task')

  // taskInput.simulate('change',{target: {value: 'Second Task'}}) // NOTE: doesn't work
  taskInput.node.value='Second Task'
  taskInput.simulate('change', taskInput) // NOTE: works as a replacement
  expect(taskInput.props().value).toEqual('Second Task')
})

[ljharb]

It's not meant to cause a change; it's mean to call the onChange function.

I recommend avoiding simulate, and manually invoking the prop function you want instead.

[Falieson]

Good to know, thanks - I probably spent an hour trying to hunt down the solution w/o anyone saying that a particular way is the better way to do it.

[DannyRyman]

Hmm, using node.value no longer works "Attempted to access ReactWrapper::node, which was previously a private property on Enzyme ReactWrapper instances, but is no longer and should not be relied upon. Consider using the getElement() method instead". Is there an alternative way of setting the value?

[ljharb]

There's a getNode function.

[bjudson]

Using mocha 3, react 16, and enzyme 3, this worked for me:

wrapper.find('input').instance().value = "foo";

[igorify]

Thanks @bjudson .
Start using
wrapper.find('input').instance().value = "foo"
instead of
wrapper.find('input').node.value = "foo",

because according to documentation, node method is private in enzyme3 https://airbnb.io/enzyme/docs/guides/migration-from-2-to-3.html#private-properties-and-methods-have-been-removed

[abhinavsingi]

seems better than #76 (comment)
and also works
as mentioned above - wrapper.find('input').instance().value = "foo"

[Quadriphobs1]

I am trying this with a redux state component, The dispatch is working as I can confirm from the action logging out the output but the reducer is not working as I cant seems to get a logged out output at all
Any idea what could be wrong

[engmyahya]

This worked with me:

it("Successfully add an employee to the employees' list when the form submitted",function(){
   const wrapper = mount(<App/>);
   const addEmpWapper = wrapper.find('AddEmployee');
   addEmpWapper.find("#txtName").getDOMNode().value = "Youki";
   addEmpWapper.find("#txtImgUrl").getDOMNode().value = "ImageUrl1";
   addEmpWapper.find("#txtDesc").getDOMNode().value = "Cute baby.";

   const form = addEmpWapper.find('form');
   form.simulate("submit");
   // I already had 3 employees in the app's states bag.
   expect(wrapper.state().employees).to.have.lengthOf(4);
 });

[saicharanp]

@engmyahya Your code throws a typescript error for me - Property value does not exist on type Element

[anupammaurya]

here is my code..

const input = MobileNumberComponent.find('input')
// when
input.props().onChange({target: {
   id: 'mobile-no',
   value: '1234567900'
}});
MobileNumberComponent.update()
const Footer = (loginComponent.find('Footer'))
expect(Footer.find('Buttons').props().disabled).equals(false)

I have update my DOM with componentname.update()
And then checking submit button validation(disable/enable) with length 10 digit.

[Joshua-rose]

@engmyahya Your code throws a typescript error for me - Property value does not exist on type Element

You need to cast the elements as HTMLInputElement
i.e.

it("Successfully add an employee to the employees' list when the form submitted",function(){
   const wrapper = mount(<App/>);
   const addEmpWapper = wrapper.find('AddEmployee');

   const txtName = addEmpWapper.find("#txtName").getDOMNode() as HTMLInputElement;
   txtName.value = "Youki";
   const txtImgUrl = addEmpWapper.find("#txtImgUrl").getDOMNode() as HTMLInputElement
   txtImgUrl.value = "ImageUrl1";
   const txtDesc = addEmpWapper.find("#txtDesc").getDOMNode() as HTMLInputElement
   txtDesc.value = "Cute baby.";

   const form = addEmpWapper.find('form');
   form.simulate("submit");
   // I already had 3 employees in the app's states bag.
   expect(wrapper.state().employees).to.have.lengthOf(4);
 });