servers/src/filesystem/__tests__/lib.test.ts
Riley cda92bdaac
fix(filesystem): create_directory doesn't create parent directories (#4631)
validatePath()'s ENOENT fallback checked only the immediate parent
directory before allowing a new path through. Creating a path with
more than one missing level (e.g. a/b/c when none of a, b, c exist)
made the immediate parent check fail with "Parent directory does not
exist", even though fs.mkdir was already called with recursive: true
one level up in the create_directory handler and an existing allowed
ancestor was available further up the tree.

Walk up through missing ancestors until an existing one is found (or
the filesystem root is reached), verifying that ancestor still
resolves inside an allowed directory via realpath. The top-level
lexical containment check already ran against the full target path,
so this only extends how far the existence/symlink check climbs.

Fixes #4629

Co-authored-by: Riley <313779891+rileybuilds@users.noreply.github.com>
Co-authored-by: olaservo <olahungerford@gmail.com>
Co-authored-by: Claude Fable 5 <noreply@anthropic.com>
2026-08-28 10:58:19 -07:00

883 lines
32 KiB
TypeScript

import { describe, it, expect, beforeEach, afterEach, vi } from 'vitest';
import fs from 'fs/promises';
import path from 'path';
import os from 'os';
import {
// Pure utility functions
formatSize,
normalizeLineEndings,
createUnifiedDiff,
// Security & validation functions
validatePath,
setAllowedDirectories,
// File operations
getFileStats,
readFileContent,
writeFileContent,
moveFile,
// Search & filtering functions
searchFilesWithValidation,
// File editing functions
applyFileEdits,
tailFile,
headFile
} from '../lib.js';
// Mock fs module
vi.mock('fs/promises');
const mockFs = fs as any;
function createMockFileHandle(content: Buffer) {
return {
read: vi.fn(
async (buffer: Buffer, offset: number, length: number, position: number) => {
const bytesRead = content.copy(
buffer,
offset,
position,
Math.min(position + length, content.length),
);
return { bytesRead, buffer };
},
),
close: vi.fn().mockResolvedValue(undefined),
};
}
describe('Lib Functions', () => {
beforeEach(() => {
vi.clearAllMocks();
// Set up allowed directories for tests
const allowedDirs = process.platform === 'win32' ? ['C:\\Users\\test', 'C:\\temp', 'C:\\allowed'] : ['/home/user', '/tmp', '/allowed'];
setAllowedDirectories(allowedDirs);
});
afterEach(() => {
vi.restoreAllMocks();
// Clear allowed directories after tests
setAllowedDirectories([]);
});
describe('Pure Utility Functions', () => {
describe('formatSize', () => {
it('formats bytes correctly', () => {
expect(formatSize(0)).toBe('0 B');
expect(formatSize(512)).toBe('512 B');
expect(formatSize(1024)).toBe('1.00 KB');
expect(formatSize(1536)).toBe('1.50 KB');
expect(formatSize(1048576)).toBe('1.00 MB');
expect(formatSize(1073741824)).toBe('1.00 GB');
expect(formatSize(1099511627776)).toBe('1.00 TB');
});
it('handles edge cases', () => {
expect(formatSize(1023)).toBe('1023 B');
expect(formatSize(1025)).toBe('1.00 KB');
expect(formatSize(1048575)).toBe('1024.00 KB');
});
it('handles very large numbers beyond TB', () => {
// The function only supports up to TB, so very large numbers will show as TB
expect(formatSize(1024 * 1024 * 1024 * 1024 * 1024)).toBe('1024.00 TB');
expect(formatSize(Number.MAX_SAFE_INTEGER)).toContain('TB');
});
it('handles negative numbers', () => {
// Negative numbers should return '0 B' as file sizes cannot be negative
expect(formatSize(-1)).toBe('0 B');
expect(formatSize(-1024)).toBe('0 B');
expect(formatSize(-1000000)).toBe('0 B');
expect(formatSize(-0)).toBe('0 B');
});
it('handles decimal numbers', () => {
expect(formatSize(1536.5)).toBe('1.50 KB');
expect(formatSize(1023.9)).toBe('1023.9 B');
});
it('handles very small positive numbers', () => {
expect(formatSize(1)).toBe('1 B');
expect(formatSize(0.5)).toBe('0.5 B');
expect(formatSize(0.1)).toBe('0.1 B');
});
});
describe('normalizeLineEndings', () => {
it('converts CRLF to LF', () => {
expect(normalizeLineEndings('line1\r\nline2\r\nline3')).toBe('line1\nline2\nline3');
});
it('leaves LF unchanged', () => {
expect(normalizeLineEndings('line1\nline2\nline3')).toBe('line1\nline2\nline3');
});
it('handles mixed line endings', () => {
expect(normalizeLineEndings('line1\r\nline2\nline3\r\n')).toBe('line1\nline2\nline3\n');
});
it('handles empty string', () => {
expect(normalizeLineEndings('')).toBe('');
});
});
describe('createUnifiedDiff', () => {
it('creates diff for simple changes', () => {
const original = 'line1\nline2\nline3';
const modified = 'line1\nmodified line2\nline3';
const diff = createUnifiedDiff(original, modified, 'test.txt');
expect(diff).toContain('--- test.txt');
expect(diff).toContain('+++ test.txt');
expect(diff).toContain('-line2');
expect(diff).toContain('+modified line2');
});
it('handles CRLF normalization', () => {
const original = 'line1\r\nline2\r\n';
const modified = 'line1\nmodified line2\n';
const diff = createUnifiedDiff(original, modified);
expect(diff).toContain('-line2');
expect(diff).toContain('+modified line2');
});
it('handles identical content', () => {
const content = 'line1\nline2\nline3';
const diff = createUnifiedDiff(content, content);
// Should not contain any +/- lines for identical content (excluding header lines)
expect(diff.split('\n').filter((line: string) => line.startsWith('+++') || line.startsWith('---'))).toHaveLength(2);
expect(diff.split('\n').filter((line: string) => line.startsWith('+') && !line.startsWith('+++'))).toHaveLength(0);
expect(diff.split('\n').filter((line: string) => line.startsWith('-') && !line.startsWith('---'))).toHaveLength(0);
});
it('handles empty content', () => {
const diff = createUnifiedDiff('', '');
expect(diff).toContain('--- file');
expect(diff).toContain('+++ file');
});
it('handles default filename parameter', () => {
const diff = createUnifiedDiff('old', 'new');
expect(diff).toContain('--- file');
expect(diff).toContain('+++ file');
});
it('handles custom filename', () => {
const diff = createUnifiedDiff('old', 'new', 'custom.txt');
expect(diff).toContain('--- custom.txt');
expect(diff).toContain('+++ custom.txt');
});
});
});
describe('Security & Validation Functions', () => {
describe('validatePath', () => {
// Use Windows-compatible paths for testing
const allowedDirs = process.platform === 'win32' ? ['C:\\Users\\test', 'C:\\temp'] : ['/home/user', '/tmp'];
beforeEach(() => {
mockFs.realpath.mockImplementation(async (path: any) => path.toString());
});
it('validates allowed paths', async () => {
const testPath = process.platform === 'win32' ? 'C:\\Users\\test\\file.txt' : '/home/user/file.txt';
const result = await validatePath(testPath);
expect(result).toBe(testPath);
});
it('rejects disallowed paths', async () => {
const testPath = process.platform === 'win32' ? 'C:\\Windows\\System32\\file.txt' : '/etc/passwd';
await expect(validatePath(testPath))
.rejects.toThrow('Access denied - path outside allowed directories');
});
it('handles non-existent files by checking parent directory', async () => {
const newFilePath = process.platform === 'win32' ? 'C:\\Users\\test\\newfile.txt' : '/home/user/newfile.txt';
const parentPath = process.platform === 'win32' ? 'C:\\Users\\test' : '/home/user';
// Create an error with the ENOENT code that the implementation checks for
const enoentError = new Error('ENOENT') as NodeJS.ErrnoException;
enoentError.code = 'ENOENT';
mockFs.realpath
.mockRejectedValueOnce(enoentError)
.mockResolvedValueOnce(parentPath);
const result = await validatePath(newFilePath);
expect(result).toBe(path.resolve(newFilePath));
});
it('walks past multiple missing ancestors to an existing allowed directory', async () => {
// e.g. create_directory('/home/user/nonexistent/nested/newfile.txt') when
// neither 'nonexistent' nor 'nonexistent/nested' exist yet, but '/home/user'
// (an allowed directory) does. Regression test for #4629.
const newFilePath = process.platform === 'win32' ? 'C:\\Users\\test\\nonexistent\\nested\\newfile.txt' : '/home/user/nonexistent/nested/newfile.txt';
const enoentError = new Error('ENOENT') as NodeJS.ErrnoException;
enoentError.code = 'ENOENT';
// The path itself is missing. The resolver then realpaths the allowed
// directory ('/home/user'), which falls through to the beforeEach base
// implementation and echoes the path back as-is. readdir is mocked to
// undefined, so every component below it counts as missing.
mockFs.realpath.mockRejectedValueOnce(enoentError);
const result = await validatePath(newFilePath);
expect(result).toBe(path.resolve(newFilePath));
});
it('rejects when no ancestor directory exists at all', async () => {
const newFilePath = process.platform === 'win32' ? 'C:\\Users\\test\\nonexistent\\newfile.txt' : '/home/user/nonexistent/newfile.txt';
const enoentError = new Error('ENOENT') as NodeJS.ErrnoException;
enoentError.code = 'ENOENT';
// Every ancestor, all the way up to the filesystem root, is missing.
mockFs.realpath.mockRejectedValue(enoentError);
await expect(validatePath(newFilePath))
.rejects.toThrow('Parent directory does not exist');
});
it('resolves relative paths against allowed directories instead of process.cwd()', async () => {
const relativePath = 'test-file.txt';
const originalCwd = process.cwd;
// Mock process.cwd to return a directory outside allowed directories
const disallowedCwd = process.platform === 'win32' ? 'C:\\Windows\\System32' : '/root';
(process as any).cwd = vi.fn(() => disallowedCwd);
try {
const result = await validatePath(relativePath);
// Result should be resolved against first allowed directory, not process.cwd()
const expectedPath = process.platform === 'win32'
? path.resolve('C:\\Users\\test', relativePath)
: path.resolve('/home/user', relativePath);
expect(result).toBe(expectedPath);
expect(result).not.toContain(disallowedCwd);
} finally {
// Restore original process.cwd
process.cwd = originalCwd;
}
});
});
});
describe('File Operations', () => {
describe('getFileStats', () => {
it('returns file statistics', async () => {
const mockStats = {
size: 1024,
birthtime: new Date('2023-01-01'),
mtime: new Date('2023-01-02'),
atime: new Date('2023-01-03'),
isDirectory: () => false,
isFile: () => true,
mode: 0o644
};
mockFs.stat.mockResolvedValueOnce(mockStats as any);
const result = await getFileStats('/test/file.txt');
expect(result).toEqual({
size: 1024,
created: new Date('2023-01-01'),
modified: new Date('2023-01-02'),
accessed: new Date('2023-01-03'),
isDirectory: false,
isFile: true,
permissions: '644'
});
});
it('handles directory statistics', async () => {
const mockStats = {
size: 4096,
birthtime: new Date('2023-01-01'),
mtime: new Date('2023-01-02'),
atime: new Date('2023-01-03'),
isDirectory: () => true,
isFile: () => false,
mode: 0o755
};
mockFs.stat.mockResolvedValueOnce(mockStats as any);
const result = await getFileStats('/test/dir');
expect(result.isDirectory).toBe(true);
expect(result.isFile).toBe(false);
expect(result.permissions).toBe('755');
});
});
describe('readFileContent', () => {
it('reads file with default encoding', async () => {
mockFs.readFile.mockResolvedValueOnce('file content');
const result = await readFileContent('/test/file.txt');
expect(result).toBe('file content');
expect(mockFs.readFile).toHaveBeenCalledWith('/test/file.txt', 'utf-8');
});
it('reads file with custom encoding', async () => {
mockFs.readFile.mockResolvedValueOnce('file content');
const result = await readFileContent('/test/file.txt', 'ascii');
expect(result).toBe('file content');
expect(mockFs.readFile).toHaveBeenCalledWith('/test/file.txt', 'ascii');
});
});
describe('writeFileContent', () => {
it('writes file content', async () => {
mockFs.writeFile.mockResolvedValueOnce(undefined);
await writeFileContent('/test/file.txt', 'new content');
expect(mockFs.writeFile).toHaveBeenCalledWith('/test/file.txt', 'new content', { encoding: "utf-8", flag: 'wx' });
});
it('preserves file permissions when overwriting existing file', async () => {
// First writeFile call with 'wx' flag fails because file exists
mockFs.writeFile.mockRejectedValueOnce(Object.assign(new Error('EEXIST'), { code: 'EEXIST' }));
// stat returns executable permissions
mockFs.stat.mockResolvedValueOnce({ mode: 0o100755 });
// Second writeFile (to temp) succeeds
mockFs.writeFile.mockResolvedValueOnce(undefined);
mockFs.rename.mockResolvedValueOnce(undefined);
mockFs.chmod.mockResolvedValueOnce(undefined);
await writeFileContent('/test/script.sh', 'new content');
expect(mockFs.stat).toHaveBeenCalledWith('/test/script.sh');
expect(mockFs.chmod).toHaveBeenCalledWith('/test/script.sh', 0o755);
});
it('does not fail the write when chmod fails', async () => {
mockFs.writeFile.mockRejectedValueOnce(Object.assign(new Error('EEXIST'), { code: 'EEXIST' }));
mockFs.stat.mockResolvedValueOnce({ mode: 0o100755 });
mockFs.writeFile.mockResolvedValueOnce(undefined);
mockFs.rename.mockResolvedValueOnce(undefined);
mockFs.chmod.mockRejectedValueOnce(Object.assign(new Error('EPERM'), { code: 'EPERM' }));
await expect(writeFileContent('/test/script.sh', 'new content')).resolves.toBeUndefined();
expect(mockFs.unlink).not.toHaveBeenCalled();
});
});
describe('moveFile', () => {
it('moves the file when the destination does not exist', async () => {
const enoent = Object.assign(new Error('not found'), { code: 'ENOENT' });
mockFs.lstat.mockRejectedValueOnce(enoent);
mockFs.rename.mockResolvedValueOnce(undefined);
await moveFile('/test/source.txt', '/test/dest.txt');
expect(mockFs.rename).toHaveBeenCalledWith('/test/source.txt', '/test/dest.txt');
});
it('fails without overwriting when the destination already exists', async () => {
// lstat resolving means the destination is occupied.
mockFs.lstat.mockResolvedValueOnce({} as any);
await expect(moveFile('/test/source.txt', '/test/dest.txt')).rejects.toThrow(
'Destination already exists'
);
expect(mockFs.rename).not.toHaveBeenCalled();
});
});
});
describe('Search & Filtering Functions', () => {
describe('searchFilesWithValidation', () => {
beforeEach(() => {
mockFs.realpath.mockImplementation(async (path: any) => path.toString());
});
it('excludes files matching exclude patterns', async () => {
const mockEntries = [
{ name: 'test.txt', isDirectory: () => false },
{ name: 'test.log', isDirectory: () => false },
{ name: 'node_modules', isDirectory: () => true }
];
mockFs.readdir.mockResolvedValueOnce(mockEntries as any);
const testDir = process.platform === 'win32' ? 'C:\\allowed\\dir' : '/allowed/dir';
const allowedDirs = process.platform === 'win32' ? ['C:\\allowed'] : ['/allowed'];
// Mock realpath to return the same path for validation to pass
mockFs.realpath.mockImplementation(async (inputPath: any) => {
const pathStr = inputPath.toString();
// Return the path as-is for validation
return pathStr;
});
const result = await searchFilesWithValidation(
testDir,
'*test*',
allowedDirs,
{ excludePatterns: ['*.log', 'node_modules'] }
);
const expectedResult = process.platform === 'win32' ? 'C:\\allowed\\dir\\test.txt' : '/allowed/dir/test.txt';
expect(result).toEqual([expectedResult]);
});
it('handles validation errors during search', async () => {
const mockEntries = [
{ name: 'test.txt', isDirectory: () => false },
{ name: 'invalid_file.txt', isDirectory: () => false }
];
mockFs.readdir.mockResolvedValueOnce(mockEntries as any);
// Mock validatePath to throw error for invalid_file.txt
mockFs.realpath.mockImplementation(async (path: any) => {
if (path.toString().includes('invalid_file.txt')) {
throw new Error('Access denied');
}
return path.toString();
});
const testDir = process.platform === 'win32' ? 'C:\\allowed\\dir' : '/allowed/dir';
const allowedDirs = process.platform === 'win32' ? ['C:\\allowed'] : ['/allowed'];
const result = await searchFilesWithValidation(
testDir,
'*test*',
allowedDirs,
{}
);
// Should only return the valid file, skipping the invalid one
const expectedResult = process.platform === 'win32' ? 'C:\\allowed\\dir\\test.txt' : '/allowed/dir/test.txt';
expect(result).toEqual([expectedResult]);
});
it('handles complex exclude patterns with wildcards', async () => {
const mockEntries = [
{ name: 'test.txt', isDirectory: () => false },
{ name: 'test.backup', isDirectory: () => false },
{ name: 'important_test.js', isDirectory: () => false }
];
mockFs.readdir.mockResolvedValueOnce(mockEntries as any);
const testDir = process.platform === 'win32' ? 'C:\\allowed\\dir' : '/allowed/dir';
const allowedDirs = process.platform === 'win32' ? ['C:\\allowed'] : ['/allowed'];
const result = await searchFilesWithValidation(
testDir,
'*test*',
allowedDirs,
{ excludePatterns: ['*.backup'] }
);
const expectedResults = process.platform === 'win32' ? [
'C:\\allowed\\dir\\test.txt',
'C:\\allowed\\dir\\important_test.js'
] : [
'/allowed/dir/test.txt',
'/allowed/dir/important_test.js'
];
expect(result).toEqual(expectedResults);
});
});
});
describe('File Editing Functions', () => {
describe('applyFileEdits', () => {
beforeEach(() => {
mockFs.readFile.mockResolvedValue('line1\nline2\nline3\n');
mockFs.writeFile.mockResolvedValue(undefined);
mockFs.stat.mockResolvedValue({ mode: 0o100644 });
mockFs.chmod.mockResolvedValue(undefined);
});
it('applies simple text replacement', async () => {
const edits = [
{ oldText: 'line2', newText: 'modified line2' }
];
mockFs.rename.mockResolvedValueOnce(undefined);
const result = await applyFileEdits('/test/file.txt', edits, false);
expect(result).toContain('modified line2');
// Should write to temporary file then rename
expect(mockFs.writeFile).toHaveBeenCalledWith(
expect.stringMatching(/\/test\/file\.txt\.[a-f0-9]+\.tmp$/),
'line1\nmodified line2\nline3\n',
'utf-8'
);
expect(mockFs.rename).toHaveBeenCalledWith(
expect.stringMatching(/\/test\/file\.txt\.[a-f0-9]+\.tmp$/),
'/test/file.txt'
);
});
it('treats dollar signs in replacement text literally', async () => {
const edits = [
{ oldText: 'line2', newText: "price=$$; match=$&; before=$`; after=$'" }
];
mockFs.rename.mockResolvedValueOnce(undefined);
await applyFileEdits('/test/file.txt', edits, false);
expect(mockFs.writeFile).toHaveBeenCalledWith(
expect.stringMatching(/\/test\/file\.txt\.[a-f0-9]+\.tmp$/),
"line1\nprice=$$; match=$&; before=$`; after=$'\nline3\n",
'utf-8'
);
});
it('handles dry run mode', async () => {
const edits = [
{ oldText: 'line2', newText: 'modified line2' }
];
const result = await applyFileEdits('/test/file.txt', edits, true);
expect(result).toContain('modified line2');
expect(mockFs.writeFile).not.toHaveBeenCalled();
});
it('applies multiple edits sequentially', async () => {
const edits = [
{ oldText: 'line1', newText: 'first line' },
{ oldText: 'line3', newText: 'third line' }
];
mockFs.rename.mockResolvedValueOnce(undefined);
await applyFileEdits('/test/file.txt', edits, false);
expect(mockFs.writeFile).toHaveBeenCalledWith(
expect.stringMatching(/\/test\/file\.txt\.[a-f0-9]+\.tmp$/),
'first line\nline2\nthird line\n',
'utf-8'
);
expect(mockFs.rename).toHaveBeenCalledWith(
expect.stringMatching(/\/test\/file\.txt\.[a-f0-9]+\.tmp$/),
'/test/file.txt'
);
});
it('handles whitespace-flexible matching', async () => {
mockFs.readFile.mockResolvedValue(' line1\n line2\n line3\n');
const edits = [
{ oldText: 'line2', newText: 'modified line2' }
];
mockFs.rename.mockResolvedValueOnce(undefined);
await applyFileEdits('/test/file.txt', edits, false);
expect(mockFs.writeFile).toHaveBeenCalledWith(
expect.stringMatching(/\/test\/file\.txt\.[a-f0-9]+\.tmp$/),
' line1\n modified line2\n line3\n',
'utf-8'
);
expect(mockFs.rename).toHaveBeenCalledWith(
expect.stringMatching(/\/test\/file\.txt\.[a-f0-9]+\.tmp$/),
'/test/file.txt'
);
});
it('preserves file permissions after applying edits', async () => {
mockFs.stat.mockResolvedValue({ mode: 0o100755 });
const edits = [
{ oldText: 'line2', newText: 'modified line2' }
];
mockFs.rename.mockResolvedValueOnce(undefined);
await applyFileEdits('/test/script.sh', edits, false);
expect(mockFs.stat).toHaveBeenCalledWith('/test/script.sh');
expect(mockFs.chmod).toHaveBeenCalledWith('/test/script.sh', 0o755);
});
it('does not restore permissions in dry run mode', async () => {
const edits = [
{ oldText: 'line2', newText: 'modified line2' }
];
await applyFileEdits('/test/file.txt', edits, true);
expect(mockFs.chmod).not.toHaveBeenCalled();
});
it('throws error for non-matching edits', async () => {
const edits = [
{ oldText: 'nonexistent line', newText: 'replacement' }
];
await expect(applyFileEdits('/test/file.txt', edits, false))
.rejects.toThrow('Could not find exact match for edit');
});
it('handles complex multi-line edits with indentation', async () => {
mockFs.readFile.mockResolvedValue('function test() {\n console.log("hello");\n return true;\n}');
const edits = [
{
oldText: ' console.log("hello");\n return true;',
newText: ' console.log("world");\n console.log("test");\n return false;'
}
];
mockFs.rename.mockResolvedValueOnce(undefined);
await applyFileEdits('/test/file.js', edits, false);
expect(mockFs.writeFile).toHaveBeenCalledWith(
expect.stringMatching(/\/test\/file\.js\.[a-f0-9]+\.tmp$/),
'function test() {\n console.log("world");\n console.log("test");\n return false;\n}',
'utf-8'
);
expect(mockFs.rename).toHaveBeenCalledWith(
expect.stringMatching(/\/test\/file\.js\.[a-f0-9]+\.tmp$/),
'/test/file.js'
);
});
it('handles edits with different indentation patterns', async () => {
mockFs.readFile.mockResolvedValue(' if (condition) {\n doSomething();\n }');
const edits = [
{
oldText: 'doSomething();',
newText: 'doSomethingElse();\n doAnotherThing();'
}
];
mockFs.rename.mockResolvedValueOnce(undefined);
await applyFileEdits('/test/file.js', edits, false);
expect(mockFs.writeFile).toHaveBeenCalledWith(
expect.stringMatching(/\/test\/file\.js\.[a-f0-9]+\.tmp$/),
' if (condition) {\n doSomethingElse();\n doAnotherThing();\n }',
'utf-8'
);
expect(mockFs.rename).toHaveBeenCalledWith(
expect.stringMatching(/\/test\/file\.js\.[a-f0-9]+\.tmp$/),
'/test/file.js'
);
});
it('handles CRLF line endings in file content', async () => {
mockFs.readFile.mockResolvedValue('line1\r\nline2\r\nline3\r\n');
const edits = [
{ oldText: 'line2', newText: 'modified line2' }
];
mockFs.rename.mockResolvedValueOnce(undefined);
await applyFileEdits('/test/file.txt', edits, false);
expect(mockFs.writeFile).toHaveBeenCalledWith(
expect.stringMatching(/\/test\/file\.txt\.[a-f0-9]+\.tmp$/),
'line1\nmodified line2\nline3\n',
'utf-8'
);
expect(mockFs.rename).toHaveBeenCalledWith(
expect.stringMatching(/\/test\/file\.txt\.[a-f0-9]+\.tmp$/),
'/test/file.txt'
);
});
});
describe('tailFile', () => {
it('handles empty files', async () => {
mockFs.stat.mockResolvedValue({ size: 0 } as any);
const result = await tailFile('/test/empty.txt', 5);
expect(result).toBe('');
expect(mockFs.open).not.toHaveBeenCalled();
});
it('calls stat to check file size', async () => {
mockFs.stat.mockResolvedValue({ size: 100 } as any);
// Mock file handle with proper typing
const mockFileHandle = {
read: vi.fn(),
close: vi.fn()
} as any;
mockFileHandle.read.mockResolvedValue({ bytesRead: 0 });
mockFileHandle.close.mockResolvedValue(undefined);
mockFs.open.mockResolvedValue(mockFileHandle);
await tailFile('/test/file.txt', 2);
expect(mockFs.stat).toHaveBeenCalledWith('/test/file.txt');
expect(mockFs.open).toHaveBeenCalledWith('/test/file.txt', 'r');
});
it('handles files with content and returns last lines', async () => {
mockFs.stat.mockResolvedValue({ size: 50 } as any);
const mockFileHandle = {
read: vi.fn(),
close: vi.fn()
} as any;
// Simulate reading file content in chunks
mockFileHandle.read
.mockResolvedValueOnce({ bytesRead: 20, buffer: Buffer.from('line3\nline4\nline5\n') })
.mockResolvedValueOnce({ bytesRead: 0 });
mockFileHandle.close.mockResolvedValue(undefined);
mockFs.open.mockResolvedValue(mockFileHandle);
const result = await tailFile('/test/file.txt', 2);
expect(mockFileHandle.close).toHaveBeenCalled();
});
it('preserves UTF-8 characters split across chunk boundaries', async () => {
const content = Buffer.concat([
Buffer.from('discard\n'),
Buffer.from('界'),
Buffer.alloc(1017, 'a'),
Buffer.from('\nlast'),
]);
const mockFileHandle = createMockFileHandle(content);
mockFs.stat.mockResolvedValue({ size: content.length } as any);
mockFs.open.mockResolvedValue(mockFileHandle);
const result = await tailFile('/test/file.txt', 2);
expect(result).toBe(`界${'a'.repeat(1017)}\nlast`);
});
it('handles read errors gracefully', async () => {
mockFs.stat.mockResolvedValue({ size: 100 } as any);
const mockFileHandle = {
read: vi.fn(),
close: vi.fn()
} as any;
mockFileHandle.read.mockResolvedValue({ bytesRead: 0 });
mockFileHandle.close.mockResolvedValue(undefined);
mockFs.open.mockResolvedValue(mockFileHandle);
await tailFile('/test/file.txt', 5);
expect(mockFileHandle.close).toHaveBeenCalled();
});
});
describe('headFile', () => {
it('opens file for reading', async () => {
// Mock file handle with proper typing
const mockFileHandle = {
read: vi.fn(),
close: vi.fn()
} as any;
mockFileHandle.read.mockResolvedValue({ bytesRead: 0 });
mockFileHandle.close.mockResolvedValue(undefined);
mockFs.open.mockResolvedValue(mockFileHandle);
await headFile('/test/file.txt', 2);
expect(mockFs.open).toHaveBeenCalledWith('/test/file.txt', 'r');
});
it('handles files with content and returns first lines', async () => {
const mockFileHandle = {
read: vi.fn(),
close: vi.fn()
} as any;
// Simulate reading file content with newlines
mockFileHandle.read
.mockResolvedValueOnce({ bytesRead: 20, buffer: Buffer.from('line1\nline2\nline3\n') })
.mockResolvedValueOnce({ bytesRead: 0 });
mockFileHandle.close.mockResolvedValue(undefined);
mockFs.open.mockResolvedValue(mockFileHandle);
const result = await headFile('/test/file.txt', 2);
expect(mockFileHandle.close).toHaveBeenCalled();
});
it('preserves UTF-8 characters split across chunk boundaries', async () => {
const content = Buffer.concat([
Buffer.alloc(1023, 'a'),
Buffer.from('界\nsecond'),
]);
const mockFileHandle = createMockFileHandle(content);
mockFs.open.mockResolvedValue(mockFileHandle);
const result = await headFile('/test/file.txt', 1);
expect(result).toBe(`${'a'.repeat(1023)}界`);
});
it('handles files with leftover content', async () => {
const mockFileHandle = {
read: vi.fn(),
close: vi.fn()
} as any;
// Simulate reading file content without final newline
mockFileHandle.read
.mockResolvedValueOnce({ bytesRead: 15, buffer: Buffer.from('line1\nline2\nend') })
.mockResolvedValueOnce({ bytesRead: 0 });
mockFileHandle.close.mockResolvedValue(undefined);
mockFs.open.mockResolvedValue(mockFileHandle);
const result = await headFile('/test/file.txt', 5);
expect(mockFileHandle.close).toHaveBeenCalled();
});
it('handles reaching requested line count', async () => {
const mockFileHandle = {
read: vi.fn(),
close: vi.fn()
} as any;
// Simulate reading exactly the requested number of lines
mockFileHandle.read
.mockResolvedValueOnce({ bytesRead: 12, buffer: Buffer.from('line1\nline2\n') })
.mockResolvedValueOnce({ bytesRead: 0 });
mockFileHandle.close.mockResolvedValue(undefined);
mockFs.open.mockResolvedValue(mockFileHandle);
const result = await headFile('/test/file.txt', 2);
expect(mockFileHandle.close).toHaveBeenCalled();
});
});
});
});