# ToolResultContainer Layout System Implementation Plan

> **For Claude:** REQUIRED SUB-SKILL: Use superpowers:executing-plans to implement this plan task-by-task.

**Goal:** Create a standard two-column layout (gutter | content) for all tool results, so every renderer is width-contained with a visible continuation gutter on multi-line output.

**Architecture:** A new `ToolResultContainer` component wraps every tool result. It renders a fixed-width gutter column (`⎿` on first line, `│` on continuations) and a flex content column. It computes `availableWidth` once and passes it to child renderers. All four renderers (CodeBlock, DiffBlock, StructuredList, MarkdownText) gain an `availableWidth` prop and truncation consistency.

**Tech Stack:** Ink (React for CLIs), `ink-testing-library` for tests, vitest.

---

### Task 1: Add `availableWidth` prop to all renderers (types only)

**Files:**

- Modify: `source/components/ToolOutput/CodeBlock.tsx` (Props type)
- Modify: `source/components/ToolOutput/DiffBlock.tsx` (Props type)
- Modify: `source/components/ToolOutput/StructuredList.tsx` (Props type)
- Modify: `source/components/ToolOutput/MarkdownText.tsx` (Props type)
- Modify: `source/components/ToolOutput/ToolOutputRenderer.tsx` (Props type, pass-through)

**Step 1: Add `availableWidth` to all renderer Props types and ToolOutputRenderer**

In each of the four renderers, add `availableWidth?: number` to the `Props` type. In `ToolOutputRenderer`, add it to its own Props and forward it to each renderer.

CodeBlock.tsx — change Props:

```tsx
type Props = {
	content: string;
	language?: string;
	maxLines?: number;
	availableWidth?: number;
};
```

DiffBlock.tsx — change Props:

```tsx
type Props = {
	oldText: string;
	newText: string;
	maxLines?: number;
	availableWidth?: number;
};
```

StructuredList.tsx — change Props:

```tsx
type Props = {
	items: ListItem[];
	maxItems?: number;
	availableWidth?: number;
};
```

MarkdownText.tsx — change Props:

```tsx
type Props = {
	content: string;
	maxLines?: number;
	availableWidth?: number;
};
```

ToolOutputRenderer.tsx — change Props and forward:

```tsx
type Props = {
	toolName: string;
	toolInput: Record<string, unknown>;
	toolResponse: unknown;
	availableWidth?: number;
};
```

Forward `availableWidth` to each `<CodeBlock>`, `<DiffBlock>`, `<StructuredList>`, `<MarkdownText>` in the switch.

**Step 2: Run typecheck**

Run: `npx tsc --noEmit`
Expected: PASS (all new props are optional)

**Step 3: Commit**

```bash
git add source/components/ToolOutput/
git commit -m "feat: add availableWidth prop to all tool output renderers"
```

---

### Task 2: Add `maxLines` to DiffBlock and MarkdownText

Both currently render unbounded content. Add truncation.

**Files:**

- Modify: `source/components/ToolOutput/DiffBlock.tsx`
- Modify: `source/components/ToolOutput/MarkdownText.tsx`
- Modify: `source/types/toolOutput.ts` (add `maxLines` to diff variant)
- Modify: `source/utils/toolExtractors.ts` (add maxLines to extractEdit)
- Test: `source/components/ToolOutput/DiffBlock.test.tsx` (create)
- Test: `source/components/ToolOutput/MarkdownText.test.tsx` (create)

**Step 1: Write the failing test for DiffBlock truncation**

Create `source/components/ToolOutput/DiffBlock.test.tsx`:

```tsx
import React from 'react';
import {describe, it, expect} from 'vitest';
import {render} from 'ink-testing-library';
import DiffBlock from './DiffBlock.js';

describe('DiffBlock', () => {
	it('returns null for empty old and new text', () => {
		const {lastFrame} = render(<DiffBlock oldText="" newText="" />);
		expect(lastFrame()).toBe('');
	});

	it('renders old lines with - prefix and new lines with + prefix', () => {
		const {lastFrame} = render(
			<DiffBlock oldText="old line" newText="new line" />,
		);
		const frame = lastFrame() ?? '';
		expect(frame).toContain('- old line');
		expect(frame).toContain('+ new line');
	});

	it('truncates when total lines exceed maxLines', () => {
		const oldText = Array.from({length: 30}, (_, i) => `old ${i}`).join('\n');
		const newText = Array.from({length: 30}, (_, i) => `new ${i}`).join('\n');
		const {lastFrame} = render(
			<DiffBlock oldText={oldText} newText={newText} maxLines={10} />,
		);
		const frame = lastFrame() ?? '';
		// Should show truncation indicator
		expect(frame).toContain('more lines');
		// Should not contain lines beyond the limit
		expect(frame).not.toContain('old 29');
	});
});
```

**Step 2: Run test to verify it fails**

Run: `npx vitest run source/components/ToolOutput/DiffBlock.test.tsx`
Expected: FAIL — `maxLines` prop doesn't exist yet, no truncation.

**Step 3: Implement DiffBlock truncation**

Update `source/components/ToolOutput/DiffBlock.tsx`:

```tsx
import React from 'react';
import {Box, Text} from 'ink';
import {useTheme} from '../../theme/index.js';

type Props = {
	oldText: string;
	newText: string;
	maxLines?: number;
	availableWidth?: number;
};

export default function DiffBlock({
	oldText,
	newText,
	maxLines,
}: Props): React.ReactNode {
	const theme = useTheme();

	if (!oldText && !newText) return null;

	const oldLines = oldText.split('\n');
	const newLines = newText.split('\n');
	const allLines = [
		...oldLines.map(line => ({prefix: '- ', line, color: theme.status.error})),
		...newLines.map(line => ({
			prefix: '+ ',
			line,
			color: theme.status.success,
		})),
	];

	const truncated = maxLines != null && allLines.length > maxLines;
	const displayLines = truncated ? allLines.slice(0, maxLines) : allLines;
	const omitted = truncated ? allLines.length - maxLines! : 0;

	return (
		<Box flexDirection="column">
			{displayLines.map((entry, i) => (
				<Text key={i} color={entry.color}>
					{entry.prefix}
					{entry.line}
				</Text>
			))}
			{truncated && <Text dimColor>({omitted} more lines)</Text>}
		</Box>
	);
}
```

**Step 4: Run test to verify it passes**

Run: `npx vitest run source/components/ToolOutput/DiffBlock.test.tsx`
Expected: PASS

**Step 5: Write the failing test for MarkdownText truncation**

Create `source/components/ToolOutput/MarkdownText.test.tsx`:

```tsx
import React from 'react';
import {describe, it, expect} from 'vitest';
import {render} from 'ink-testing-library';
import MarkdownText from './MarkdownText.js';

describe('MarkdownText', () => {
	it('returns null for empty content', () => {
		const {lastFrame} = render(<MarkdownText content="" />);
		expect(lastFrame()).toBe('');
	});

	it('renders markdown content', () => {
		const {lastFrame} = render(<MarkdownText content="hello **world**" />);
		const frame = lastFrame() ?? '';
		expect(frame).toContain('hello');
		expect(frame).toContain('world');
	});

	it('truncates when output exceeds maxLines', () => {
		const content = Array.from({length: 50}, (_, i) => `Line ${i}`).join(
			'\n\n',
		);
		const {lastFrame} = render(<MarkdownText content={content} maxLines={5} />);
		const frame = lastFrame() ?? '';
		expect(frame).toContain('more lines');
		expect(frame).not.toContain('Line 49');
	});
});
```

**Step 6: Run test to verify it fails**

Run: `npx vitest run source/components/ToolOutput/MarkdownText.test.tsx`
Expected: FAIL — `maxLines` prop doesn't exist yet.

**Step 7: Implement MarkdownText truncation**

In `source/components/ToolOutput/MarkdownText.tsx`, after the `marked.parse()` call, add line truncation:

Replace the return section (lines 136-152) with:

```tsx
export default function MarkdownText({
	content,
	maxLines,
	availableWidth,
}: Props): React.ReactNode {
	if (!content) return null;

	const width = availableWidth ?? process.stdout.columns ?? 80;
	const marked = createMarked(width);

	let rendered: string;
	try {
		const result = marked.parse(content);
		rendered = typeof result === 'string' ? result.trimEnd() : content;
	} catch {
		rendered = content;
	}

	// Truncate rendered output if maxLines is set
	if (maxLines != null) {
		const lines = rendered.split('\n');
		if (lines.length > maxLines) {
			const omitted = lines.length - maxLines;
			rendered = lines.slice(0, maxLines).join('\n');
			return (
				<Box flexDirection="column">
					<Text>{rendered}</Text>
					<Text dimColor>({omitted} more lines)</Text>
				</Box>
			);
		}
	}

	return <Text>{rendered}</Text>;
}
```

Add `Box` to the ink import at line 2:

```tsx
import {Box, Text} from 'ink';
```

**Step 8: Run test to verify it passes**

Run: `npx vitest run source/components/ToolOutput/MarkdownText.test.tsx`
Expected: PASS

**Step 9: Add `maxLines` to the `diff` variant in RenderableOutput**

In `source/types/toolOutput.ts`, update the diff variant:

```tsx
export type RenderableOutput =
	| {type: 'code'; content: string; language?: string; maxLines?: number}
	| {type: 'diff'; oldText: string; newText: string; maxLines?: number}
	| {type: 'list'; items: ListItem[]; maxItems?: number}
	| {type: 'text'; content: string; maxLines?: number};
```

**Step 10: Set default maxLines in extractors**

In `source/utils/toolExtractors.ts`:

- `extractEdit` (line 176): change return to `{type: 'diff', oldText, newText, maxLines: 40}`
- `extractWebFetch` (line 248): add `maxLines: 30` to the text return
- `extractWebSearch`: add `maxLines: 20` to the links return
- `extractTask` (line 328): add `maxLines: 30` to the text return
- Fallback (line 366): add `maxLines: 40`

Update `ToolOutputRenderer.tsx` to pass `maxLines` to the `text` and `diff` cases:

```tsx
case 'diff':
	return <DiffBlock oldText={output.oldText} newText={output.newText} maxLines={output.maxLines} availableWidth={availableWidth} />;
// ...
case 'text':
	return <MarkdownText content={output.content} maxLines={output.maxLines} availableWidth={availableWidth} />;
```

**Step 11: Run all tests**

Run: `npx vitest run`
Expected: PASS

**Step 12: Commit**

```bash
git add source/components/ToolOutput/ source/types/toolOutput.ts source/utils/toolExtractors.ts
git commit -m "feat: add truncation to DiffBlock and MarkdownText renderers"
```

---

### Task 3: Create `ToolResultContainer` component

The core layout component: fixed gutter column + flex content column with `availableWidth` computation.

**Files:**

- Create: `source/components/ToolOutput/ToolResultContainer.tsx`
- Test: `source/components/ToolOutput/ToolResultContainer.test.tsx` (create)
- Modify: `source/components/ToolOutput/index.ts` (add export)

**Step 1: Write the failing test**

Create `source/components/ToolOutput/ToolResultContainer.test.tsx`:

```tsx
import React from 'react';
import {describe, it, expect} from 'vitest';
import {render} from 'ink-testing-library';
import {Text} from 'ink';
import ToolResultContainer from './ToolResultContainer.js';

describe('ToolResultContainer', () => {
	it('renders gutter prefix on first line', () => {
		const {lastFrame} = render(
			<ToolResultContainer>
				<Text>content</Text>
			</ToolResultContainer>,
		);
		const frame = lastFrame() ?? '';
		expect(frame).toContain('⎿');
		expect(frame).toContain('content');
	});

	it('returns null when children is null', () => {
		const {lastFrame} = render(
			<ToolResultContainer>{null}</ToolResultContainer>,
		);
		expect(lastFrame()).toBe('');
	});

	it('passes availableWidth to render prop', () => {
		let receivedWidth = 0;
		render(
			<ToolResultContainer>
				{width => {
					receivedWidth = width;
					return <Text>test</Text>;
				}}
			</ToolResultContainer>,
		);
		// availableWidth = terminal columns - GUTTER_WIDTH(2) - LEFT_MARGIN(2) - RIGHT_PAD(1)
		expect(receivedWidth).toBeGreaterThan(0);
	});
});
```

**Step 2: Run test to verify it fails**

Run: `npx vitest run source/components/ToolOutput/ToolResultContainer.test.tsx`
Expected: FAIL — file doesn't exist.

**Step 3: Implement ToolResultContainer**

Create `source/components/ToolOutput/ToolResultContainer.tsx`:

```tsx
import React from 'react';
import {Box, Text} from 'ink';

/**
 * Layout constants for the two-column tool result layout.
 *
 *   [LEFT_MARGIN][GUTTER][CONTENT..................][RIGHT_PAD]
 *   2 chars      2 chars  flex                      1 char
 *
 * GUTTER renders ⎿ on the first line. Multi-line continuation
 * is handled by Ink's flexbox — the gutter column stays fixed.
 */
const LEFT_MARGIN = 2;
const GUTTER_WIDTH = 2; // "⎿ " or "│ "
const RIGHT_PAD = 1;
const TOTAL_OVERHEAD = LEFT_MARGIN + GUTTER_WIDTH + RIGHT_PAD;

const GUTTER_CHAR = '\u23bf'; // ⎿

type Props = {
	children: React.ReactNode | ((availableWidth: number) => React.ReactNode);
	dimGutter?: boolean;
	gutterColor?: string;
};

export default function ToolResultContainer({
	children,
	dimGutter = true,
	gutterColor,
}: Props): React.ReactNode {
	if (children == null) return null;

	const terminalWidth = process.stdout.columns || 80;
	const availableWidth = Math.max(terminalWidth - TOTAL_OVERHEAD, 20);

	const content =
		typeof children === 'function' ? children(availableWidth) : children;

	if (content == null) return null;

	return (
		<Box paddingLeft={LEFT_MARGIN}>
			<Box width={GUTTER_WIDTH} flexShrink={0}>
				<Text dimColor={dimGutter} color={gutterColor}>
					{GUTTER_CHAR}{' '}
				</Text>
			</Box>
			<Box flexDirection="column" flexGrow={1} flexShrink={1}>
				{content}
			</Box>
		</Box>
	);
}

export {TOTAL_OVERHEAD, GUTTER_WIDTH, LEFT_MARGIN, RIGHT_PAD};
```

**Step 4: Add export to index.ts**

In `source/components/ToolOutput/index.ts`, add:

```tsx
export {default as ToolResultContainer} from './ToolResultContainer.js';
export {TOTAL_OVERHEAD} from './ToolResultContainer.js';
```

**Step 5: Run test to verify it passes**

Run: `npx vitest run source/components/ToolOutput/ToolResultContainer.test.tsx`
Expected: PASS

**Step 6: Commit**

```bash
git add source/components/ToolOutput/
git commit -m "feat: add ToolResultContainer layout component"
```

---

### Task 4: Wire ToolResultContainer into UnifiedToolCallEvent

Replace the ad-hoc `<Box paddingLeft={2}><Text>{RESPONSE_PREFIX}</Text>...` pattern with `<ToolResultContainer>`.

**Files:**

- Modify: `source/components/UnifiedToolCallEvent.tsx`
- Test: `source/components/UnifiedToolCallEvent.test.tsx` (update assertions)

**Step 1: Update UnifiedToolCallEvent to use ToolResultContainer**

In `source/components/UnifiedToolCallEvent.tsx`:

1. Add import:

```tsx
import {ToolResultContainer} from './ToolOutput/index.js';
```

2. Remove `RESPONSE_PREFIX` from the import of `hookEventUtils.js` (keep other imports).

3. Replace the success response block (lines 126-141):

Old:

```tsx
responseNode = (
	<Box paddingLeft={2}>
		<Text dimColor>{RESPONSE_PREFIX}</Text>
		<Box flexDirection="column" flexShrink={1}>
			<ToolOutputRenderer
				toolName={toolName}
				toolInput={toolInput}
				toolResponse={...}
			/>
		</Box>
	</Box>
);
```

New:

```tsx
responseNode = (
	<ToolResultContainer>
		{availableWidth => (
			<ToolOutputRenderer
				toolName={toolName}
				toolInput={toolInput}
				toolResponse={
					isPostToolUseEvent(resolvedPost)
						? resolvedPost.tool_response
						: undefined
				}
				availableWidth={availableWidth}
			/>
		)}
	</ToolResultContainer>
);
```

4. Replace the blocked response block (lines 108-112):

Old:

```tsx
responseNode = (
	<Box paddingLeft={2}>
		<Text color={statusColors.blocked}>{RESPONSE_PREFIX}User rejected</Text>
	</Box>
);
```

New:

```tsx
responseNode = (
	<ToolResultContainer gutterColor={statusColors.blocked} dimGutter={false}>
		<Text color={statusColors.blocked}>User rejected</Text>
	</ToolResultContainer>
);
```

5. Replace the failure response block (lines 117-124):

Old:

```tsx
responseNode = (
	<Box paddingLeft={2}>
		<Text color={statusColors.blocked}>{formatResponseBlock(errorText)}</Text>
	</Box>
);
```

New:

```tsx
responseNode = (
	<ToolResultContainer gutterColor={statusColors.blocked} dimGutter={false}>
		<Text color={statusColors.blocked}>{errorText}</Text>
	</ToolResultContainer>
);
```

6. Replace the pending "Running…" block (lines 146-150):

Old:

```tsx
responseNode = (
	<Box paddingLeft={2}>
		<Text dimColor>{'\u2514 Running\u2026'}</Text>
	</Box>
);
```

New:

```tsx
responseNode = (
	<ToolResultContainer>
		<Text dimColor>Running…</Text>
	</ToolResultContainer>
);
```

**Step 2: Update test assertions**

In `source/components/UnifiedToolCallEvent.test.tsx`, the `⎿` character is now rendered by `ToolResultContainer`. Existing assertions should still pass since they check for content text (`Bash`, `hello world`, `command not found`, `User rejected`) — not for layout details. Verify no assertion depends on `RESPONSE_PREFIX` being inline with content.

**Step 3: Run tests**

Run: `npx vitest run source/components/UnifiedToolCallEvent.test.tsx`
Expected: PASS

**Step 4: Commit**

```bash
git add source/components/UnifiedToolCallEvent.tsx source/components/UnifiedToolCallEvent.test.tsx
git commit -m "refactor: use ToolResultContainer in UnifiedToolCallEvent"
```

---

### Task 5: Wire ToolResultContainer into SubagentEvent

Same pattern as Task 4 but for the subagent rendering path.

**Files:**

- Modify: `source/components/SubagentEvent.tsx`

**Step 1: Update SubagentEvent to use ToolResultContainer**

In `source/components/SubagentEvent.tsx`:

1. Add import:

```tsx
import {ToolResultContainer} from './ToolOutput/index.js';
```

2. In `ChildEvent` function, replace the PostToolUse success block (lines 79-92):

Old:

```tsx
<Box paddingLeft={2}>
	<Text dimColor>{RESPONSE_PREFIX}</Text>
	<Box flexDirection="column" flexShrink={1}>
		<ToolOutputRenderer
			toolName={payload.tool_name}
			toolInput={payload.tool_input}
			toolResponse={...}
		/>
	</Box>
</Box>
```

New:

```tsx
<ToolResultContainer>
	{availableWidth => (
		<ToolOutputRenderer
			toolName={payload.tool_name}
			toolInput={payload.tool_input}
			toolResponse={
				isPostToolUseEvent(payload) ? payload.tool_response : undefined
			}
			availableWidth={availableWidth}
		/>
	)}
</ToolResultContainer>
```

3. Remove `RESPONSE_PREFIX` from the `hookEventUtils.js` import if no longer used elsewhere in the file. (Note: `ResponseBlock` at line 77 still uses it for the completed subagent response — leave `ResponseBlock` import.)

**Step 2: Run all tests**

Run: `npx vitest run`
Expected: PASS

**Step 3: Commit**

```bash
git add source/components/SubagentEvent.tsx
git commit -m "refactor: use ToolResultContainer in SubagentEvent"
```

---

### Task 6: Make MarkdownText use `availableWidth` instead of `process.stdout.columns`

Currently MarkdownText computes its own width from `process.stdout.columns`, which doesn't account for the gutter it's nested inside.

**Files:**

- Modify: `source/components/ToolOutput/MarkdownText.tsx`

**Step 1: Update width computation**

This was already done in Task 2 Step 7 — `MarkdownText` now uses `availableWidth ?? process.stdout.columns ?? 80`. No further changes needed — just verify it works end-to-end.

**Step 2: Run tests**

Run: `npx vitest run source/components/ToolOutput/MarkdownText.test.tsx`
Expected: PASS

**Step 3: Commit** (skip if no changes)

---

### Task 7: Normalize truncation limits across extractors

Standardize: code=20 lines, diff=40 lines, list=15 items, text=30 lines.

**Files:**

- Modify: `source/utils/toolExtractors.ts`
- Test: `source/utils/toolExtractors.test.ts` (update if affected)

**Step 1: Update extractor limits**

In `source/utils/toolExtractors.ts`:

- `extractBash` line 119: change `maxLines: 30` → `maxLines: 20`
- `extractRead` line 164: keep `maxLines: 20` (already correct)
- `extractEdit` line 176: add `maxLines: 40` (done in Task 2)
- `extractNotebookEdit` line 318: keep `maxLines: 20` (already correct)
- `extractGrep` line 214: keep `maxItems: 15`
- `extractGlob` line 228/237: change `maxItems: 20` → `maxItems: 15`
- `extractWebFetch`: add `maxLines: 30` (done in Task 2)
- `extractWebSearch`: add `maxLines: 20` (done in Task 2)
- `extractTask`: add `maxLines: 30` (done in Task 2)
- Fallback line 366: add `maxLines: 40` (done in Task 2)

**Step 2: Run tests**

Run: `npx vitest run source/utils/toolExtractors.test.ts`
Expected: PASS (or update any assertions that check specific maxItems values)

**Step 3: Run lint and typecheck**

Run: `npm run lint && npx tsc --noEmit`
Expected: PASS

**Step 4: Commit**

```bash
git add source/utils/toolExtractors.ts source/utils/toolExtractors.test.ts
git commit -m "refactor: normalize truncation limits across tool extractors"
```

---

### Task 8: Clean up dead code

Remove `RESPONSE_PREFIX`, `CONTINUATION_PAD`, and `formatResponseBlock` from `hookEventUtils.tsx` if no longer used.

**Files:**

- Modify: `source/components/hookEventUtils.tsx`
- Test: `source/components/HookEvent.test.tsx` (update if affected)

**Step 1: Check usage of RESPONSE_PREFIX and formatResponseBlock**

Search for remaining usages across the codebase. If `ResponseBlock` component in `hookEventUtils.tsx` still uses `RESPONSE_PREFIX` and `formatResponseBlock` (for subagent completed responses), keep them. If `ResponseBlock` can also be migrated to `ToolResultContainer`, do so and then remove the dead code.

Likely outcome: `ResponseBlock` is still used by `SubagentEvent` (line 77 and 157) for the subagent's completed response text. Migrate it:

Replace `ResponseBlock` in `hookEventUtils.tsx`:

```tsx
export function ResponseBlock({
	response,
	isFailed,
}: {
	response: string;
	isFailed: boolean;
}): React.ReactNode {
	if (!response) return null;
	return (
		<ToolResultContainer
			gutterColor={isFailed ? 'red' : undefined}
			dimGutter={!isFailed}
		>
			<Text color={isFailed ? 'red' : undefined} dimColor={!isFailed}>
				{response}
			</Text>
		</ToolResultContainer>
	);
}
```

Add import: `import {ToolResultContainer} from './ToolOutput/index.js';`

After this, if `RESPONSE_PREFIX`, `CONTINUATION_PAD`, and `formatResponseBlock` have zero remaining usages, delete them.

**Step 2: Run all tests**

Run: `npx vitest run`
Expected: PASS

**Step 3: Run lint**

Run: `npm run lint`
Expected: PASS

**Step 4: Commit**

```bash
git add source/components/hookEventUtils.tsx source/components/HookEvent.test.tsx
git commit -m "refactor: migrate ResponseBlock to ToolResultContainer, remove dead prefix code"
```

---

### Task 9: Final integration test

**Files:**

- Test: `source/components/UnifiedToolCallEvent.test.tsx`

**Step 1: Add integration test for gutter rendering**

Add to `UnifiedToolCallEvent.test.tsx`:

```tsx
it('renders ⎿ gutter prefix on tool result', () => {
	const post = makePostToolPayload({
		stdout: 'test output',
		stderr: '',
		interrupted: false,
		isImage: false,
		noOutputExpected: false,
	});
	const event = makePreToolEvent({postToolEvent: post.display});
	const {lastFrame} = render(<UnifiedToolCallEvent event={event} />);
	const frame = lastFrame() ?? '';
	expect(frame).toContain('\u23bf'); // ⎿
	expect(frame).toContain('test output');
});
```

**Step 2: Run full test suite**

Run: `npx vitest run`
Expected: PASS

**Step 3: Run lint and typecheck**

Run: `npm run lint && npx tsc --noEmit`
Expected: PASS

**Step 4: Build**

Run: `npm run build`
Expected: PASS

**Step 5: Commit**

```bash
git add source/components/UnifiedToolCallEvent.test.tsx
git commit -m "test: add integration test for ToolResultContainer gutter"
```
