Testing React Router with Link

Question

I am having a nightmare finding a good solution for testing a React Router link. It is passing on the 'renders Categories properly' however zero links are being passed through to the test, I have tried so many different things and have still got nowhere.

Below is what i am trying to test:

Component

import React from 'react';
import { Link } from 'react-router';

class Categories extends React.Component {

constructor(props, context){
    super(props);
    context.router
}

render() {
    return (
        <nav className="categories">
          <ul>
              <li><Link to="devices">Devices</Link></li>
              <li><Link to="cases">Cases</Link></li>
              <li><Link to="layouts">Layouts</Link></li>
              <li><Link to="designs">Designs</Link></li>
          </ul>
        </nav>
    );
  }
}

Categories.contextTypes = {
 router: React.PropTypes.func.isRequired
};

export default Categories;

StubRouterContext

import React from 'react';
import objectAssign from 'object-assign';

var stubRouterContext = (Component, props, stubs) => {
function RouterStub() { }

objectAssign(RouterStub, {
  makePath () {},
  makeHref () {},
  transitionTo () {},
  replaceWith () {},
  goBack () {},
  getCurrentPath () {},
  getCurrentRoutes () {},
  getCurrentPathname () {},
  getCurrentParams () {},
  getCurrentQuery () {},
  isActive () {},
  getRouteAtDepth() {},
  setRouteComponentAtDepth() {}
 }, stubs)

return React.createClass({
childContextTypes: {
    router: React.PropTypes.func,
    routeDepth: React.PropTypes.number
},

getChildContext () {
    console.log('blah');
  return {
    router: RouterStub,
    routeDepth: 0
  };
},

render () {
  return <Component {...props} />
}
});
};

export default stubRouterContext;

Component Test

var expect = require('chai').expect;

var React = require('react/addons');
var Categories = require('../app/src/js/components/Categories.React.js');
var stubRouterContext = require('../test-utils/stubRouterContext.js');
var TestUtils = React.addons.TestUtils;

describe('Categories', function() {
  var categoriesWithContext = stubRouterContext(Categories);

  it('renders Categories properly', function() {
  var categories = TestUtils.renderIntoDocument(<categoriesWithContext />, {});
});

it('renders 4 links', function() {
  var catLinks = TestUtils.scryRenderedDOMComponentsWithTag(categoriesWithContext, 'a');
  expect(catLinks).to.have.length(4);
});
});

Answer 1

I had exactly the same problem. In the latest versions of react-router, you do not need context to render link elements so this isn't a problem. However, if you are stuck on pre API 1.0 versions as I am, the stubRouterContext approach works well.

The only reason OP and I found that our wrapper was rendering empty is the use of a camelCase component name.

var categoriesWithContext = stubRouterContext(Categories); becomes var CategoriesWithContext = stubRouterContext(Categories);.

Therfore var categories = TestUtils.renderIntoDocument(<categoriesWithContext />,{}); becomes var categories = TestUtils.renderIntoDocument(<CategoriesWithContext />,{});.

Explanation of this approach is here - https://gist.github.com/sebmarkbage/f1f4ba40816e7d7848ad.

Answer 2

The first thing I notice is that you're not re-rendering "categoriesWithContext" in the second test.

it('renders 4 links', function() {
  var categories = TestUtils.renderIntoDocument(<categoriesWithContext />, {});
  var catLinks = TestUtils.scryRenderedDOMComponentsWithTag(categories, 'a');
  expect(catLinks).to.have.length(4);
});

Though I haven't run your code myself, the next thing I notice is the way you're fetching the links. In a test I have, I must dig through the hierarchy manually.

Try this.

it('renders 4 links', function() {
  var categories = TestUtils.renderIntoDocument(<categoriesWithContext />, {});
  var ul = TestUtils.findRenderedDOMComponentWithTag(categories, 'ul');
  var lis = TestUtils.scryRenderedDOMComponentsWithTag(ul, 'li');
  lis.forEach(function(li) {
    // this should throw if <a/> is not found
    var a = TestUtils.findRenderedDOMComponentWithTag(li, 'a');
    // but write an explicit expectation anyway
    expect(a);
  });
});