Storybook

Storybook is a development environment for UI components. It allows you to browse a component library, view the different states of each component, and interactively develop and test components.

This guide will briefly walk you through using Storybook within an Nx workspace.

Setting Up Storybook

Add the Storybook plugin

yarn add --dev @nrwl/storybook

Using Storybook

Generating Storybook Configuration

You can generate Storybook configuration for an individual project with this command:

nx g @nrwl/angular:storybook-configuration project-name

Running Storybook

Serve Storybook using this command:

nx run project-name:storybook

Anatomy of the Storybook setup

When running the Nx Storybook generator, it'll configure the Nx workspace to be able to run Storybook seamlessly. It'll create

a global Storybook configuration
a project specific Storybook configuration

The global Storybook configuration allows to set addon-ons or custom webpack configuration at a global level that applies to all Storybook's within the Nx workspace. You can find that folder at .storybook/ at the root of the workspace.

<workspace name>/
├── .storybook/
│   ├── main.js
│   ├── tsconfig.json
├── apps/
├── libs/
├── nx.json
├── package.json
├── README.md
└── etc...

The project-specific Storybook configuration is pretty much similar to what you would have for a non-Nx setup of Storybook. There's a .storybook folder within the project root folder.

<project root>/
├── .storybook/
│   ├── main.js
│   ├── preview.js
│   ├── tsconfig.json
├── src/
├── README.md
├── tsconfig.json
└── etc...

Using Addons

To register a Storybook addon for all storybook instances in your workspace:

In /.storybook/main.js, in the addons array of the module.exports object, add the new addon:

1module.exports = {
2stories: [...],
3...,
4addons: [..., '@storybook/addon-essentials'],
5};

If a decorator is required, in each project's <project-path>/.storybook/preview.js, you can export an array called decorators.
```
1import someDecorator from 'some-storybook-addon';
2export const decorators = [someDecorator];
```

-- OR --

To register an addon for a single storybook instance, go to that project's .storybook folder:

In main.js, in the addons array of the module.exports object, add the new addon:

1module.exports = {
2stories: [...],
3...,
4addons: [..., '@storybook/addon-essentials'],
5};

If a decorator is required, in preview.js you can export an array called decorators.

1import someDecorator from 'some-storybook-addon';
2export const decorators = [someDecorator];

Auto-generate Stories

The @nrwl/angular:storybook-configuration generator has the option to automatically generate *.stories.ts files for each component declared in the library.

<some-folder>/
├── my.component.ts
└── my.component.stories.ts

You can re-run it at a later point using the following command:

nx g @nrwl/angular:stories <project-name>

Cypress tests for Stories

Both storybook-configuration generator gives the option to set up an e2e Cypress app that is configured to run against the project's Storybook instance.

To launch Storybook and run the Cypress tests against the iframe inside of Storybook:

nx run project-name-e2e:e2e

The url that Cypress points to should look like this:

'/iframe.html?id=buttoncomponent--primary&args=text:Click+me!;padding;style:default'

buttoncomponent is a lowercase version of the Title in the *.stories.ts file.
primary is the name of an individual story.
style=default sets the style arg to a value of default.

Changing args in the url query parameters allows your Cypress tests to test different configurations of your component. You can read the documentation for more information.

Example Files

*.component.stories.ts file

1import { moduleMetadata, Story, Meta } from '@storybook/angular';
2import { ButtonComponent } from './button.component';
3
4export default {
5  title: 'ButtonComponent',
6  component: ButtonComponent,
7  decorators: [
8    moduleMetadata({
9      imports: [],
10    }),
11  ],
12} as Meta<ButtonComponent>;
13
14const Template: Story<ButtonComponent> = (args: ButtonComponent) => ({
15  props: args,
16});
17
18export const Primary = Template.bind({});
19Primary.args = {
20  text: 'Click me!',
21  padding: 0,
22  style: 'default',
23};

Cypress *.spec.ts file

1describe('shared-ui', () => {
2  beforeEach(() =>
3    cy.visit(
4      '/iframe.html?id=buttoncomponent--primary&args=text:Click+me!;padding;style:default'
5    )
6  );
7
8  it('should render the component', () => {
9    cy.get('storybook-trial-button').should('exist');
10  });
11});

Extra topics for Angular projects

Here you can find some extra topics for configuring Storybook on Angular projects.