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Maintenance: Apply stricter eslint rules for unused vars #33004

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33c549b
Update ESLint configuration: enforce no-duplicates for imports, enhan…
valentinpalkovic Nov 11, 2025
1fe3404
Apply new eslint rules
valentinpalkovic Nov 11, 2025
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2 changes: 1 addition & 1 deletion code/__mocks__/lodash-es/add.js
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@@ -1,4 +1,4 @@
function add(a, b) {
function add(_a, _b) {
return 'mocked 3';
}

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3 changes: 1 addition & 2 deletions code/addons/a11y/src/components/A11yContext.test.tsx
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Expand Up @@ -13,8 +13,7 @@ import {
import type { AxeResults } from 'axe-core';
import * as api from 'storybook/manager-api';

import { EVENTS, UI_STATE_ID } from '../constants';
import { RuleType } from '../types';
import { EVENTS } from '../constants';
import { A11yContextProvider, useA11yContext } from './A11yContext';

vi.mock('storybook/manager-api');
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2 changes: 1 addition & 1 deletion code/addons/a11y/src/manager.tsx
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Expand Up @@ -47,7 +47,7 @@ const Title = () => {
);
};

addons.register(ADDON_ID, (api) => {
addons.register(ADDON_ID, (_api) => {
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@ndelangen ndelangen Nov 12, 2025

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I personally do not see how this improves things.
TS already warns about unused vars, and they get compiled away at build-time.

I'd be pretty unhappy about unused vars getting removed automatically, unless they start with a _-character, since I often work on new functions and consts first, then the usage.

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@valentinpalkovic valentinpalkovic Nov 12, 2025 •
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I'd be pretty unhappy about unused vars getting removed automatically, unless they start with a _-character, since I often work on new functions and consts first, then the usage.

You don't have to worry about this. Unused args aren't removed automatically. They are just marked as errors. You still have to remove them manually. That's pretty handy because we are forced to consider whether a particular argument is necessary or whether we want to keep it for the function signature.

You're right that TypeScript already warns about that in your IDE, but you don't have that warning during code reviews. It is not evident to the reviewer at first glance whether a variable/argument is used or not. Using an underscore notation improves the readability.

addons.add(PANEL_ID, {
title: '',
type: types.TOOL,
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2 changes: 0 additions & 2 deletions code/addons/docs/src/blocks/blocks/ArgTypes.stories.tsx
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@@ -1,5 +1,3 @@
import React from 'react';
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@ndelangen ndelangen Nov 12, 2025

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We can't do this yet.

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@valentinpalkovic valentinpalkovic Nov 12, 2025

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Please add some elaboration for future reference.

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@ndelangen ndelangen Nov 12, 2025

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Due to the way we build our code & how manager-builder is configured.
It was setup in the days before the jsx-runtime was a thing, and has has not been changed since.


import type { PlayFunctionContext } from 'storybook/internal/csf';

import type { Meta, StoryObj } from '@storybook/react-vite';
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2 changes: 0 additions & 2 deletions code/addons/docs/src/blocks/blocks/Controls.stories.tsx
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@@ -1,5 +1,3 @@
import React from 'react';

import type { PlayFunctionContext } from 'storybook/internal/csf';

import type { Meta, StoryObj } from '@storybook/react-vite';
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2 changes: 0 additions & 2 deletions code/addons/docs/src/blocks/blocks/Description.stories.tsx
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@@ -1,5 +1,3 @@
import React from 'react';

import type { Meta, StoryObj } from '@storybook/react-vite';

import { Button as ButtonComponent } from '../examples/Button';
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2 changes: 1 addition & 1 deletion code/addons/docs/src/blocks/blocks/Source.tsx
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@@ -1,4 +1,4 @@
import type { ComponentProps, FC } from 'react';
import type { ComponentProps } from 'react';
import React, { useContext, useMemo } from 'react';

import { SourceType } from 'storybook/internal/docs-tools';
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2 changes: 0 additions & 2 deletions code/addons/docs/src/blocks/blocks/Story.stories.tsx
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@@ -1,5 +1,3 @@
import React from 'react';

import type { Meta, StoryObj } from '@storybook/react-vite';

import { expect, waitFor } from 'storybook/test';
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6 changes: 3 additions & 3 deletions code/addons/docs/src/blocks/blocks/mdx.tsx
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@@ -1,4 +1,4 @@
import type { FC, MouseEvent, PropsWithChildren, SyntheticEvent } from 'react';
import type { FC, MouseEvent, PropsWithChildren } from 'react';
import React, { useContext } from 'react';

import type { SupportedLanguage } from 'storybook/internal/components';
Expand Down Expand Up @@ -77,7 +77,7 @@ const AnchorInPage: FC<PropsWithChildren<AnchorInPageProps>> = ({ hash, children
<A
href={hash}
target="_self"
onClick={(event: SyntheticEvent) => {
onClick={() => {
const id = hash.substring(1);
const element = document.getElementById(id);
if (element) {
Expand Down Expand Up @@ -193,7 +193,7 @@ const HeaderWithOcticonAnchor: FC<PropsWithChildren<HeaderWithOcticonAnchorProps
href={hash}
tabIndex={-1}
target="_self"
onClick={(event: SyntheticEvent) => {
onClick={() => {
const element = document.getElementById(id);
if (element) {
navigate(context, hash);
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1 change: 0 additions & 1 deletion code/addons/docs/src/blocks/components/ArgsTable/ArgControl.tsx
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Expand Up @@ -6,7 +6,6 @@ import { Link } from 'storybook/internal/components';
import {
BooleanControl,
ColorControl,
type ControlProps,
DateControl,
FilesControl,
NumberControl,
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8 changes: 4 additions & 4 deletions code/addons/docs/src/blocks/components/ArgsTable/SectionRow.tsx
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Expand Up @@ -44,11 +44,11 @@ const ExpanderIconRight = styled(ChevronRightIcon)(({ theme }) => ({
display: 'inline-block',
}));

const FlexWrapper = styled.span(({ theme }) => ({
const FlexWrapper = styled.span({
display: 'flex',
lineHeight: '20px',
alignItems: 'center',
}));
});

const Section = styled.td(({ theme }) => ({
position: 'relative',
Expand Down Expand Up @@ -125,7 +125,7 @@ export const SectionRow: FC<SectionRowProps> = ({
<>
<StyledTr title={helperText}>
<Level colSpan={1}>
<ClickIntercept onClick={(e) => setExpanded(!expanded)} tabIndex={0}>
<ClickIntercept onClick={() => setExpanded(!expanded)} tabIndex={0}>
{helperText}
</ClickIntercept>
<FlexWrapper>
Expand All @@ -135,7 +135,7 @@ export const SectionRow: FC<SectionRowProps> = ({
</Level>
<StyledTd colSpan={colSpan - 1}>
<ClickIntercept
onClick={(e) => setExpanded(!expanded)}
onClick={() => setExpanded(!expanded)}
tabIndex={-1}
style={{ outline: 'none' }}
>
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68 changes: 33 additions & 35 deletions code/addons/docs/src/blocks/components/ArgsTable/Skeleton.tsx
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Expand Up @@ -18,43 +18,41 @@ const Row = styled.div(({ theme }) => ({
},
}));

const Column = styled.div<{ position: 'first' | 'second' | 'third' | 'last' }>(
({ position, theme }) => {
const baseStyles = {
display: 'flex',
flexDirection: 'column' as const,
gap: 5,
padding: '10px 15px',
alignItems: 'flex-start',
};
const Column = styled.div<{ position: 'first' | 'second' | 'third' | 'last' }>(({ position }) => {
const baseStyles = {
display: 'flex',
flexDirection: 'column' as const,
gap: 5,
padding: '10px 15px',
alignItems: 'flex-start',
};

// Apply the same column width ratios as the actual ArgsTable component
switch (position) {
case 'first':
return {
...baseStyles,
width: '25%',
paddingLeft: 20,
};
case 'second':
return {
...baseStyles,
width: '35%',
};
case 'third':
return {
...baseStyles,
width: '15%',
};
case 'last':
return {
...baseStyles,
width: '25%',
paddingRight: 20,
};
}
// Apply the same column width ratios as the actual ArgsTable component
switch (position) {
case 'first':
return {
...baseStyles,
width: '25%',
paddingLeft: 20,
};
case 'second':
return {
...baseStyles,
width: '35%',
};
case 'third':
return {
...baseStyles,
width: '15%',
};
case 'last':
return {
...baseStyles,
width: '25%',
paddingRight: 20,
};
}
);
});

const SkeletonText = styled.div<{ width?: number | string; height?: number }>(
({ theme, width, height }) => ({
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4 changes: 2 additions & 2 deletions code/addons/docs/src/blocks/components/Preview.tsx
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Expand Up @@ -210,7 +210,7 @@ export const Preview: FC<PreviewProps> = ({

const context = useContext(DocsContext);

const copyToClipboard = useCallback(async (text: string) => {
const copyToClipboard = useCallback(async () => {
const { createCopyToClipboardFunction } = await import('storybook/internal/components');
createCopyToClipboardFunction();
}, []);
Expand All @@ -226,7 +226,7 @@ export const Preview: FC<PreviewProps> = ({

e.preventDefault();
if (additionalActionItems.filter((item) => item.title === 'Copied').length === 0) {
copyToClipboard(source?.props.code ?? '').then(() => {
copyToClipboard().then(() => {
setAdditionalActionItems([
...additionalActionItems,
{
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2 changes: 1 addition & 1 deletion code/addons/docs/src/blocks/controls/Color.tsx
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Expand Up @@ -76,7 +76,7 @@ const Swatch = ({ value, style, ...props }: SwatchProps) => {
return <SwatchColor {...props} style={{ ...style, backgroundImage }} />;
};

const Input = styled(Form.Input)(({ theme, readOnly }) => ({
const Input = styled(Form.Input)(({ theme }) => ({
width: '100%',
paddingLeft: 30,
paddingRight: 30,
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1 change: 1 addition & 0 deletions code/addons/docs/src/blocks/examples/ArgTypesParameters.tsx
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@@ -1,3 +1,4 @@
/* eslint-disable @typescript-eslint/no-unused-vars */
import React from 'react';

type PropTypes = { a?: string; b: string };
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2 changes: 1 addition & 1 deletion code/addons/docs/src/blocks/examples/Button.stories.tsx
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Expand Up @@ -101,7 +101,7 @@ export const Clicking: Story = {
</>
);
},
play: async ({ canvasElement, id }) => {
play: async ({ canvasElement }) => {
const canvas = within(canvasElement);

const button = canvas.getByText('Increment');
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1 change: 1 addition & 0 deletions code/addons/docs/src/blocks/examples/ControlsParameters.tsx
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@@ -1,3 +1,4 @@
/* eslint-disable @typescript-eslint/no-unused-vars */
import React from 'react';

type PropTypes = { a?: string; b: string };
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1 change: 0 additions & 1 deletion code/addons/docs/src/preset.ts
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Expand Up @@ -3,7 +3,6 @@ import { fileURLToPath } from 'node:url';

import { logger } from 'storybook/internal/node-logger';
import type { Options, PresetProperty, StorybookConfigRaw } from 'storybook/internal/types';
import { type CsfEnricher } from 'storybook/internal/types';

import type { CsfPluginOptions } from '@storybook/csf-plugin';

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2 changes: 2 additions & 0 deletions code/addons/links/src/react/components/link.test.tsx
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Expand Up @@ -58,6 +58,8 @@ describe('LinkTo', () => {
expect(container.firstChild).toMatchInlineSnapshot(`
<a
href="originpathname?path=/story/foo--bar"
name="bar"
title="foo"
Comment on lines +61 to +62
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@coderabbitai coderabbitai bot Nov 11, 2025

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⚠️ Potential issue | 🔴 Critical

🧩 Analysis chain

Verify that forwarding title and name to the DOM anchor is intentional.

The updated snapshot shows that title and name props are now being rendered as HTML attributes on the anchor element. These props appear to be Storybook-specific identifiers (used in the SELECT_STORY event at lines 96-97), not necessarily attributes meant for the DOM:

  1. The name attribute on <a> elements is deprecated in HTML5 (replaced by id)
  2. Forwarding internal Storybook identifiers (title, name) to the DOM may pollute the HTML with unnecessary attributes

This change appears to be a side effect of the ESLint unused variable fix—if title and name were previously destructured to prevent forwarding, removing that destructuring would cause them to spread onto the DOM element.

If this forwarding is unintentional, consider explicitly destructuring these props in link.tsx to exclude them from the rest spread:

const { title, name, ...restProps } = props;
// Use title and name for story selection only
// Spread only restProps onto the anchor element

Alternatively, prefix them with an underscore in the destructuring if they're intentionally unused in that scope:

const { title: _title, name: _name, ...restProps } = props;

🏁 Script executed:

#!/bin/bash
# Locate and inspect the LinkTo component implementation in link.tsx
find . -name "link.tsx" -type f | head -5

Length of output: 112

🏁 Script executed:

#!/bin/bash
# Inspect the test file to understand context around lines 47, 61-62, and 96-97
cat code/addons/links/src/react/components/link.test.tsx | head -110

Length of output: 2353

🏁 Script executed:

#!/bin/bash
# Search for how props are destructured/spread in the LinkTo component
rg -n "title|name" code/addons/links/src/react/components/link.tsx -A 2 -B 2

Length of output: 873

🏁 Script executed:

#!/bin/bash
# Get the full link.tsx component to see the render method
cat code/addons/links/src/react/components/link.tsx

Length of output: 2074

Destructure title and name in the render method to prevent them from spreading onto the DOM anchor element.

The analysis confirms the review comment is accurate. In code/addons/links/src/react/components/link.tsx, the render() method destructures { kind, story, children, ...rest } but does NOT explicitly extract title and name. This causes them to be included in the ...rest spread onto the anchor element, polluting the DOM with Storybook-internal identifiers.

The name attribute on <a> elements is deprecated in HTML5 and these properties are meant only for story identification in event emissions—not DOM attributes.

Fix by explicitly destructuring title and name in link.tsx line 79:

const { kind, story, title, name, children, ...rest } = this.props;

This prevents them from being included in ...rest and spreading to the anchor, consistent with how kind and story are already handled. The test snapshot at lines 61–62 will need to be updated to remove the name and title attributes from the expected anchor output.

🤖 Prompt for AI Agents 
In code/addons/links/src/react/components/link.tsx around line 79 and the test
file code/addons/links/src/react/components/link.test.tsx around lines 61–62,
explicitly destructure title and name from this.props in the render method
(e.g., include title and name alongside kind and story) so they are not included
in ...rest and thus not spread onto the anchor element; then update the test
snapshot/expected output in link.test.tsx to remove the now-absent title and
name attributes from the anchor.

>
link
</a>
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2 changes: 1 addition & 1 deletion code/addons/links/src/react/components/link.tsx
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Expand Up @@ -75,7 +75,7 @@ export default class LinkTo extends PureComponent<Props, State> {
};

render() {
const { kind, title = kind, story, name = story, children, ...rest } = this.props;
const { kind, story, children, ...rest } = this.props;
const { href } = this.state;

return (
Expand Down
4 changes: 2 additions & 2 deletions code/addons/links/template/stories/linkto.stories.ts
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Expand Up @@ -60,8 +60,8 @@ export const NormalizedTitleAndName = {
export const Callback = {
args: {
onClick: linkTo(
(event: Event) => 'addons-links-linkto',
(event: Event) => 'target'
() => 'addons-links-linkto',
() => 'target'
),
},
};
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3 changes: 1 addition & 2 deletions code/addons/onboarding/src/components/Confetti/Confetti.tsx
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Expand Up @@ -14,10 +14,9 @@ const Wrapper = styled.div({
});

export const Confetti = React.memo(function Confetti({
timeToFade = 5000,
colors = ['#CA90FF', '#FC521F', '#66BF3C', '#FF4785', '#FFAE00', '#1EA7FD'],
...confettiProps
}: ComponentProps<typeof ReactConfetti> & { timeToFade?: number }) {
}: ComponentProps<typeof ReactConfetti>) {
return (
<Wrapper>
<ReactConfetti
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4 changes: 0 additions & 4 deletions code/addons/pseudo-states/src/stories/CSSAtRules.stories.tsx
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@@ -1,11 +1,7 @@
import React, { type ComponentProps } from 'react';

import { FORCE_REMOUNT } from 'storybook/internal/core-events';

import type { Meta, StoryObj } from '@storybook/react-vite';

import { useChannel, useStoryContext } from 'storybook/preview-api';

import { Button } from './CSSAtRules';
import './grid.css';

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2 changes: 1 addition & 1 deletion code/addons/themes/src/decorators/class-name.decorator.tsx
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Expand Up @@ -37,7 +37,7 @@ export const withThemeByClassName = <TRenderer extends Renderer = Renderer>({

Object.entries(themes)
.filter(([themeName]) => themeName !== selectedThemeName)
.forEach(([themeName, className]) => {
.forEach(([_themeName, className]) => {
const classes = classStringToArray(className);
if (classes.length > 0) {
parentElement.classList.remove(...classes);
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2 changes: 0 additions & 2 deletions code/addons/vitest/src/components/TestProviderRender.stories.tsx
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@@ -1,7 +1,5 @@
import React from 'react';

import { Addon_TypesEnum } from 'storybook/internal/types';

import type { Meta, StoryObj } from '@storybook/react-vite';

import { ManagerContext, addons } from 'storybook/manager-api';
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18 changes: 4 additions & 14 deletions code/addons/vitest/src/node/boot-test-runner.test.ts
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Expand Up @@ -10,8 +10,7 @@ import { execaNode } from 'execa';

import { storeOptions } from '../constants';
import { log } from '../logger';
import type { StoreEvent } from '../types';
import type { StoreState } from '../types';
import type { StoreEvent, StoreState } from '../types';
import { killTestRunner, runTestRunner } from './boot-test-runner';

let stdout: (chunk: any) => void;
Expand Down Expand Up @@ -47,27 +46,18 @@ vi.mock('../logger', () => ({
vi.mock('../../../../core/src/shared/utils/module', () => ({
importMetaResolve: vi
.fn()
.mockImplementation(
(a) => 'file://' + join(__dirname, '..', '..', 'dist', 'node', 'vitest.js')
),
.mockImplementation(() => 'file://' + join(__dirname, '..', '..', 'dist', 'node', 'vitest.js')),
}));

let statusStoreSubscriber = vi.hoisted(() => undefined);
let testProviderStoreSubscriber = vi.hoisted(() => undefined);

vi.mock('storybook/internal/core-server', async (importOriginal) => {
const actual = await importOriginal<typeof import('storybook/internal/core-server')>();
return {
...actual,
internal_universalStatusStore: {
subscribe: (listener: any) => {
statusStoreSubscriber = listener;
},
subscribe: () => {},
},
internal_universalTestProviderStore: {
subscribe: (listener: any) => {
testProviderStoreSubscriber = listener;
},
subscribe: () => {},
},
};
});
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3 changes: 0 additions & 3 deletions code/addons/vitest/src/node/test-manager.test.ts
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@@ -1,7 +1,6 @@
import { describe, expect, it, vi } from 'vitest';
import { createVitest as actualCreateVitest } from 'vitest/node';

import { Channel, type ChannelTransport } from 'storybook/internal/channels';
import { experimental_MockUniversalStore } from 'storybook/internal/core-server';
import type {
Options,
Expand Down Expand Up @@ -50,8 +49,6 @@ vi.mock('vitest/node', async (importOriginal) => ({

const createVitest = vi.mocked(actualCreateVitest);

const transport = { setHandler: vi.fn(), send: vi.fn() } satisfies ChannelTransport;
const mockChannel = new Channel({ transport });
const mockStore = new experimental_MockUniversalStore<StoreState, StoreEvent>(
{
...storeOptions,
Expand Down
4 changes: 1 addition & 3 deletions code/addons/vitest/src/preset.ts
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@@ -1,4 +1,3 @@
import { readFileSync } from 'node:fs';
import { mkdir } from 'node:fs/promises';

import type { Channel } from 'storybook/internal/channels';
Expand Down Expand Up @@ -33,8 +32,7 @@ import {
} from './constants';
import { log } from './logger';
import { runTestRunner } from './node/boot-test-runner';
import type { CachedState, ErrorLike, StoreState } from './types';
import type { StoreEvent } from './types';
import type { CachedState, ErrorLike, StoreEvent, StoreState } from './types';

type Event = {
type: 'test-discrepancy';
Expand Down
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