sb.mock() doesn't work - mocked(...).mockReturnValue is not a function

[briete]

Environment

• Operating system macOS 25.1.0
• CPU Apple M1 Pro (10 cores)
• Node.js version v22.13.1
• nuxt/cli version 3.32.0
• Package manager yarn 4.6.0
• Nuxt version 3.13.2
• Nitro version 2.13.1
• Builder vite 7.3.0
• Config -
• Modules -

Reproduction

NA

Describe the bug

sb.mock() in .storybook/preview.ts doesn't work with @storybook-vue/nuxt. The mocked() helper returns the original function instead of a mock function.

Steps to Reproduce

1. Set up module mocking in .storybook/preview.ts:

import { sb } from "storybook/test";

sb.mock(import("../composables/useMyComposable.ts"), { spy: true });

2. Use mocked() in a story:

import { mocked, fn } from "storybook/test";
import { useMyComposable } from "../composables/useMyComposable.ts";

export const Default: Story = {
  beforeEach: async () => {
    mocked(useMyComposable).mockReturnValue({
      // mock return value
    });
  },
};

3. Run Storybook and navigate to the story

Expected Behavior

mocked(useMyComposable) should return a mock function with mockReturnValue, mockImplementation, etc.

Actual Behavior

TypeError: mocked(...).mockReturnValue is not a function

The mocked() function returns the original function unchanged, without mock capabilities.

Workaround

It worked by adding the following code to .storybook/main.ts

import { createRequire } from "node:module";
import { dirname, join } from "node:path";

const config: StorybookConfig = {
  // ... other config
  
  async viteFinal(config, options) {
    // Call @storybook/builder-vite's viteFinal to enable viteMockPlugin
    const require = createRequire(import.meta.url);
    const vue3VitePath = dirname(require.resolve("@storybook/vue3-vite/package.json"));
    const builderVitePresetPath = join(vue3VitePath, "node_modules/@storybook/builder-vite/dist/preset.js");
    const { viteFinal: builderViteFinal } = await import(builderVitePresetPath);
    return builderViteFinal(config, options);
  },
};

Additional context

• https://storybook.js.org/docs/writing-stories/mocking-data-and-modules/mocking-modules

[briete]

I mistakenly thought that support for Storybook 10 was included, but it hasn't been released yet... Will this be available once Storybook 10 support is added?

[AcidRaZor]

I think it's going to be a while until we get a "v10". There was a merge in December, but I guess their pipeline is failing, considering no release since August?

One thing you could do is download the code and have the module exist for your install only to see if v10 update fixed this / try the nightly build.

I've tried getting even storybook v9 running and couldn't figure it out, so much dumb on the internet and the documentation (or just me I guess). Other modules work fine out the box, so it makes me wonder what Storybook v10 brought that's so difficult to update from v9.