eyaltoledano/claude-task-master · error · Error

Invalid subtask ID: ${subId}. Subtask ID must be a positive

Error message

Invalid subtask ID: ${subId}. Subtask ID must be a positive integer.

What it means

After splitting a dotted subtask ID, updateSubtaskStatusInFile() validates that the subtask segment is a positive integer (digits only). If the portion after the dot is non-numeric (e.g. '5.a' or '5.2x'), it throws this error so downstream numeric comparisons against subtask ids are safe.

Source

Thrown at packages/tm-core/src/modules/storage/adapters/file-storage/file-storage.ts:516

	 */
	private async updateSubtaskStatusInFile(
		tasks: Task[],
		subtaskId: string,
		newStatus: TaskStatus,
		tag?: string
	): Promise<UpdateStatusResult> {
		// Parse the subtask ID to get parent ID and subtask ID
		const parts = subtaskId.split('.');
		if (parts.length !== 2) {
			throw new Error(
				`Invalid subtask ID format: ${subtaskId}. Expected format: parentId.subtaskId`
			);
		}

		const [parentId, subIdRaw] = parts;
		const subId = subIdRaw.trim();
		if (!/^\d+$/.test(subId)) {
			throw new Error(
				`Invalid subtask ID: ${subId}. Subtask ID must be a positive integer.`
			);
		}
		const subtaskNumericId = Number(subId);

		// Find the parent task
		const parentTaskIndex = tasks.findIndex(
			(t) => String(t.id) === String(parentId)
		);

		if (parentTaskIndex === -1) {
			throw new Error(`Parent task ${parentId} not found`);
		}

		const parentTask = tasks[parentTaskIndex];

		// Find the subtask within the parent task
		const subtaskIndex = parentTask.subtasks.findIndex(

View on GitHub (pinned to c0c98d367c)

Solutions

1. Sanitize the subtask segment to digits-only before calling (e.g. parseInt and re-validate)
2. Use /^\d+\.\d+$/ to validate the full dotted ID up front
3. Confirm the subtask's numeric index from the parent task's subtasks list
4. Reject/reprompt on invalid user input before invoking the storage API

Example fix

// before
await storage.updateTaskStatus(`5.${userInput}`, 'done'); // 'abc' throws
// after
const subId = Number.parseInt(userInput, 10);
if (!Number.isInteger(subId) || subId <= 0) {
  throw new Error(`Subtask index must be a positive integer, got: ${userInput}`);
}
await storage.updateTaskStatus(`5.${subId}`, 'done');

function isPositiveIntSegment(seg: string): boolean {
  return /^\d+$/.test(seg.trim());
}
function canUpdateSubtask(id: string): boolean {
  const [parent, sub] = id.split('.');
  return id.split('.').length === 2 && /^\d+$/.test(parent) && isPositiveIntSegment(sub);
}
// guard: if (!canUpdateSubtask(id)) reject();

function isInvalidSubtaskIdError(e: unknown): e is Error {
  return e instanceof Error && e.message.startsWith('Invalid subtask ID:');
}

try {
  await storage.updateTaskStatus(subtaskId, newStatus);
} catch (e) {
  if (isInvalidSubtaskIdError(e)) {
    // coerce/re-prompt: const n = parseInt(sub, 10); if (!Number.isInteger(n) || n <= 0) ...
  } else throw e;
}

When it happens

Trigger: Passing an ID like '5.abc', '5.2x', or '5.-1' where the subtask segment is not purely digits; usually the result of unvalidated user input or mixing ID schemes from another system.

Common situations: CLI users typing descriptive text instead of the numeric subtask index, importing IDs from external trackers with alphanumeric keys, or string concatenation bugs building the subtask ID dynamically.

Related errors

• Invalid subtask ID format: ${subtaskId}. Expected format: pa
• Invalid iterations: ${iterations}. Must be a positive intege
• Invalid format: ${options.format}. Valid formats are: text,
• PARENT_TASK_NOT_FOUND
• PARENT_TASK_NO_SUBTASKS

AI-assisted analysis of eyaltoledano/claude-task-master@c0c98d367c (2026-08-29). Data as JSON: /api/errors/3b24ff03b63aacfa. Report an issue: GitHub.