StoryShots

StoryShots adds automatic Jest Snapshot Testing for Storybook.

This addon works with Storybook for:

• React
• React Native

To use StoryShots, you must use your existing Storybook stories as the input for Jest Snapshot Testing.

Getting Started

Add the following module into your app.

npm install --save-dev @nlabs/storybook-addon-storyshots

Configure your app for Jest

Usually, you might already have completed this step. If not, here are some resources for you.

• If you are using Create React App, it's already configured for Jest. You just need to create a filename with the extension .test.js.
• Otherwise check this Egghead lesson.

Note: If you use React 16, you'll need to follow these additional instructions.

Configure Storyshots

Create a new test file with the name Storyshots.test.js. (Or whatever the name you prefer, as long as it matches Jest's config testMatch). Then add following content to it:

import initStoryshots from '@nlabs/storybook-addon-storyshots';

initStoryshots();

That's all.

Now run your Jest test command. (Usually, npm test.) Then you can see all of your stories are converted as Jest snapshot tests.

Options

configPath

By default, Storyshots assumes the config directory path for your project as below:

• Storybook for React: .storybook
• Storybook for React Native: storybook

If you are using a different config directory path, you could change it like this:

import initStoryshots from '@nlabs/storybook-addon-storyshots';

initStoryshots({
  configPath: '.my-storybook-config-dir'
});

suite

By default, Storyshots groups stories inside a Jest test suite called "Storyshots". You could change it like this:

import initStoryshots from '@nlabs/storybook-addon-storyshots';

initStoryshots({
  suite: 'MyStoryshots'
});

storyKindRegex

If you'd like to only run a subset of the stories for your snapshot tests based on the story's kind:

import initStoryshots from '@nlabs/storybook-addon-storyshots';

initStoryshots({
  storyKindRegex: /^MyComponent$/
});

This can be useful if you want to separate the snapshots in directories next to each component. See an example here.

If you want to run all stories except stories of a specific kind, you can write an inverse regex which is true for all kinds except those with a specific word such as DontTest

import initStoryshots from '@nlabs/storybook-addon-storyshots';

initStoryshots({
  storyKindRegex:/^((?!.*?DontTest).)*$/
});

This can be useful while testing react components which make use of the findDomNode API since they always fail with snapshot testing while using react-test-renderer see here

storyNameRegex

If you'd like to only run a subset of the stories for your snapshot tests based on the story's name:

import initStoryshots from '@nlabs/storybook-addon-storyshots';

initStoryshots({
  storyNameRegex: /buttons/
});

framework

If you are running tests from outside of your app's directory, storyshots' detection of which framework you are using may fail. Pass "react" or "react-native" to short-circuit this.

test

Run a custom test function for each story, rather than the default (a vanilla snapshot test). Setting test will take precedence over the renderer option. See the exports section below for more details.

renderer

Pass a custom renderer (such as enzymes mount) to record snapshots.

import initStoryshots from '@nlabs/storybook-addon-storyshots';
import { mount } from 'enzyme';

initStoryshots({
  renderer: mount,
});

If you are using enzyme, you need to make sure jest knows how to serialize rendered components. You can either pass in a serializer (see below) or specify an enzyme-compatible serializer (like enzyme-to-json, jest-serializer-enzyme etc.) as the default snapshotSerializer in your config.

Example for jest config in package.json:

"devDependencies": {
    "enzyme-to-json": "^3.2.2"
},
"jest": {
    "snapshotSerializers": [
      "enzyme-to-json/serializer"
    ]
  }

serializer

Pass a custom serializer (such as enzyme-to-json) to serialize components to snapshot-comparable data.

import initStoryshots from '@nlabs/storybook-addon-storyshots';
import toJSON from 'enzyme-to-json';

initStoryshots({
  renderer: mount,
  serializer: toJSON,
});

This option only needs to be set if the default snapshotSerializers is not set in your jest config.

Exports

Apart from the default export (initStoryshots), Storyshots also exports some named test functions (see the test option above):

snapshot

The default, render the story as normal and take a Jest snapshot.

renderOnly

Just render the story, don't check the output at all (useful if you just want to ensure it doesn't error).

snapshotWithOptions(options)

Like the default, but allows you to specify a set of options for the test renderer. See for example here.

multiSnapshotWithOptions(options)

Like snapshotWithOptions, but generate a separate snapshot file for each stories file rather than a single monolithic file (as is the convention in Jest). This makes it dramatically easier to review changes.

shallowSnapshot

Take a snapshot of a shallow-rendered version of the component. Note that this option will be overriden if you pass a renderer option.

getSnapshotFileName

Utility function used in multiSnapshotWithOptions. This is made available for users who implement custom test functions that also want to take advantage of multi-file storyshots.

Example:

Let's say we wanted to create a test function for shallow && multi-file snapshots:

import initStoryshots, { getSnapshotFileName } from '@nlabs/storybook-addon-storyshots';
import { shallow } from 'enzyme';
import toJson from 'enzyme-to-json';

initStoryshots({
  test: ({ story, context }) => {
    const snapshotFileName = getSnapshotFileName(context);
    const storyElement = story.render(context);
    const shallowTree = shallow(storyElement);

    if (snapshotFileName) {
      expect(toJson(shallowTree)).toMatchSpecificSnapshot(snapshotFileName);
    }
  }
});