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@testplane/storybook

Overview​

Use the @testplane/storybook plugin to automatically check the changes in your Storybook components with screenshot testing without a single line of test code.

This plugin adds:

  • automatic screenshot tests for storybook stories;
  • an ability to write Testplane tests for storybook stories right inside of the stories.

Installation​

npm install @testplane/storybook --save-dev

Setup​

info
Storybook 6.4+ is required to use this plugin.

Storybook​

If you use storybook@6, you will need to enable buildStoriesJson feature in your storybook config:

export default {
    // ...
    features: {
        // ...
        buildStoriesJson: true,
    },
};

You don't need to do this with storybook@7 or storybook@8.

Testplane​

Add @testplane/storybook plugin into your Testplane config:

.testplane.conf.ts
export default {
    plugins: {
        "@testplane/storybook": {},

        // other Testplane plugins...
    },

    // other Testplane settings...
};

With this minimal config, you will be able to run npx testplane --storybook to autotest each storybook story with Testplane assertView command. Testplane will open each story, wait for play function to finish (if defined), and then call assertView command. These tests would be generated in runtime.

Description of configuration parameters​

ParameterTypeDefaultDescription
enabledBooleantrueEnable / disable plugin.
storybookConfigDirString".storybook"Path to the storybook configuration directory.
autoScreenshotsBooleantrueEnable / disable auto-screenshot tests
localportNumber6006Port to launch storybook dev server on.
remoteStorybookUrlString""URL of the remote Storybook. If specified, local storybook dev sever would not be launched.
browserIdsArray<String | RegExp>[]Array of browserId to run storybook tests on. By default, all of browsers, specified in Testplane config would be used
info

Storybook tests performance greatly depends on Testplane testsPerSession parameter, as these tests speeds up on reusing existing sessions, so setting values around 20+ is preferred. These tests ignore Testplane isolation. It would be turned off unconditionally.

Advanced usage​

If you have ts-node in your project, you can write your Testplane tests right inside of storybook story files:

info

Storybook story files must have .js or .ts extension for this to work. Formats jsx/tsx are not supported yet.

stories/Primary.stories.ts
import type { StoryObj } from "@storybook/react";
import type { WithTestplane } from "@testplane/storybook";

export const Primary: WithTestplane<StoryObj> = {
    args: {
        primary: true,
        label: "Button",
    },
    testplane: {
        "my test": async ({ browser, expect }) => {
            const element = await browser.$(".storybook-button");

            await expect(element).toHaveText("Button");
        },
    },
};

You can also specify extra options in story default config:

import type { WithTestplane } from "@testplane/storybook";
import type { Meta, StoryObj } from "@storybook/react";

const meta: WithTestplane<Meta<typeof Button>> = {
    title: "Example/Button",
    component: Button,
    testplane: {
        skip: false, // if true, skips all Testplane tests from this story file
        autoscreenshotSelector: ".my-selector", // Custom selector to auto-screenshot elements
        browserIds: ["chrome"], // Testplane browsers to run tests from this story file
        assertViewOpts: {
            // override default assertView options for tests from this file
            ignoreDiffPixelCount: 5,
        },
    },
};

export default meta;

If you decide to create separate config for storybook auto-tests (which is suggested), you need to specify config path via CLI option. For example:

npx testplane --storybook -c .testplane.storybook.conf.ts

This allows you to store references next to your story files:

.testplane.conf.ts
import path from "path";
import { getStoryFile } from "@testplane/storybook";

export default {
    screenshotsDir: test => {
        const relativeStoryFilePath = getStoryFile(test);
        const relativeStoryFileDirPath = path.dirname(relativeStoryFilePath);

        return path.join(relativeStoryFileDirPath, "screens", test.id, test.browserId);
    },
    // other Testplane settings...
};

In this example, screenshot references would be stored in screens/<testId>/<browserId> folder, next to each of your story files.