/**
* File System Error Helpers
*
* Utilities for creating mock filesystem errors in tests.
* These simulate real error conditions like disk full, permission denied, etc.
*/
/**
* Create a Node.js filesystem error with the proper structure
*/
export function createFsError(
code: string,
message: string,
path?: string
): NodeJS.ErrnoException {
const fullMessage = path
? `${code}: ${message}, '${path}'`
: `${code}: ${message}`;
const error = new Error(fullMessage) as NodeJS.ErrnoException;
error.code = code;
if (path) {
error.path = path;
}
return error;
}
/**
* Common filesystem errors for testing
*/
export const FS_ERRORS = {
/** Disk full / no space left on device */
ENOSPC: (path?: string) =>
createFsError('ENOSPC', 'no space left on device', path),
/** Disk quota exceeded */
EDQUOT: (path?: string) =>
createFsError('EDQUOT', 'disk quota exceeded', path),
/** Permission denied */
EACCES: (path?: string) => createFsError('EACCES', 'permission denied', path),
/** I/O error */
EIO: (path?: string) => createFsError('EIO', 'i/o error', path),
/** No such file or directory */
ENOENT: (path: string) =>
createFsError('ENOENT', `no such file or directory, open`, path),
/** Cross-device link not permitted (rename across filesystems) */
EXDEV: (oldPath?: string, newPath?: string) =>
createFsError(
'EXDEV',
`cross-device link not permitted${oldPath ? `, '${oldPath}' -> '${newPath}'` : ''}`,
oldPath
),
/** Read-only file system */
EROFS: (path?: string) =>
createFsError('EROFS', 'read-only file system', path),
/** File is busy */
EBUSY: (path?: string) =>
createFsError('EBUSY', 'resource busy or locked', path),
/** Too many open files */
EMFILE: () => createFsError('EMFILE', 'too many open files'),
/** Invalid argument */
EINVAL: (message?: string) =>
createFsError('EINVAL', message ?? 'invalid argument'),
/** File exists (for exclusive create operations) */
EEXIST: (path?: string) =>
createFsError('EEXIST', 'file already exists', path),
};
/**
* Create a session with specific stats for testing edge cases
*/
export function createTestSession(overrides: {
sessionId?: string;
version?: number;
createdAt?: string;
lastActiveAt?: string;
stats?: Partial<{
toolCalls: number | string | null | undefined | object;
promptCalls: number | string | null | undefined | object;
errors: number | string | null | undefined | object;
rateLimits: number | string | null | undefined | object;
}>;
}) {
return {
version: overrides.version ?? 1,
sessionId: overrides.sessionId ?? 'test-uuid',
createdAt: overrides.createdAt ?? '2026-01-09T10:00:00.000Z',
lastActiveAt: overrides.lastActiveAt ?? '2026-01-09T10:00:00.000Z',
stats: {
toolCalls: overrides.stats?.toolCalls ?? 0,
promptCalls: overrides.stats?.promptCalls ?? 0,
errors: overrides.stats?.errors ?? 0,
rateLimits: overrides.stats?.rateLimits ?? 0,
},
};
}
/**
* Generate truncated JSON content at various points
*/
export function generateTruncatedJson(
fullJson: string,
truncateAt: 'start' | 'middle' | 'end' | number
): string {
const length = fullJson.length;
switch (truncateAt) {
case 'start':
return fullJson.slice(0, 10);
case 'middle':
return fullJson.slice(0, Math.floor(length / 2));
case 'end':
return fullJson.slice(0, length - 1); // Missing closing brace
default:
return fullJson.slice(0, truncateAt);
}
}
/**
* Generate malformed JSON strings for testing
*/
export const MALFORMED_JSON = {
unclosedBrace: '{"unclosed": "string',
trailingComma: '{"version": 1,}',
unquotedKey: '{version: 1}',
null: 'null',
undefined: 'undefined',
array: '[]',
emptyString: '',
randomGarbage: 'invalid json{{{',
doubleComma: '{"a": 1,, "b": 2}',
missingValue: '{"a": }',
singleQuotes: "{'version': 1}",
};
