What causes "projectRoot is required for isOnDefaultBranch" in eyaltoledano/claude-task-master?

Pass a valid non-empty repository path to the function

projectRoot is required for isOnDefaultBranch

Error message

projectRoot is required for isOnDefaultBranch

What it means

isOnDefaultBranch compares the current branch with the default branch, running both lookups inside projectRoot. An empty projectRoot makes that comparison impossible, so the guard throws this error before git commands execute. It is a fail-fast argument check.

Source

Thrown at packages/tm-core/src/common/utils/git-utils.ts:265

		for (const defaultName of commonDefaults) {
			if (
				branches.includes(defaultName) ||
				remoteBranches.includes(defaultName)
			) {
				return defaultName;
			}
		}

		return null;
	}
}

/**
 * Check if we're currently on the default branch
 */
export async function isOnDefaultBranch(projectRoot: string): Promise<boolean> {
	if (!projectRoot) {
		throw new Error('projectRoot is required for isOnDefaultBranch');
	}

	try {
		const [currentBranch, defaultBranch] = await Promise.all([
			getCurrentBranch(projectRoot),
			getDefaultBranch(projectRoot)
		]);
		return (
			currentBranch !== null &&
			defaultBranch !== null &&
			currentBranch === defaultBranch
		);
	} catch (error) {
		return false;
	}
}

/**

View on GitHub (pinned to c0c98d367c)

Solutions

Pass a valid non-empty repository path to the function
Fall back to process.cwd() when the configured root is missing
Fix upstream projectRoot resolution/config loading
Wrap the call in a guard that returns false (or skips the check) when root is unknown

Example fix

// before
const onDefault = await isOnDefaultBranch(projectRoot); // ''
// after
const onDefault = projectRoot ? await isOnDefaultBranch(projectRoot) : false;

Defensive patterns

Strategy: validation

Validate before calling

if (!projectRoot || typeof projectRoot !== 'string') {
  throw new Error('isOnDefaultBranch requires a non-empty projectRoot');
}
// safe pre-check of both underlying values:
const [cur, def] = await Promise.all([getCurrentBranch(projectRoot), getDefaultBranch(projectRoot)]);
const onDefault = cur !== null && def !== null && cur === def;

Type guard

function isRoot(v: unknown): v is string {
  return typeof v === 'string' && v.trim().length > 0;
}

Try / catch

try {
  const onDefault = await isOnDefaultBranch(projectRoot);
} catch (err) {
  if (err instanceof Error && err.message.includes('isOnDefaultBranch')) {
    console.error('projectRoot missing; skipping default-branch safety check.');
    return false; // treat as NOT safe rather than crashing
  }
  throw err;
}

Prevention

Treat the check as a safety gate: when root is unknown, assume not-on-default and skip risky writes
Resolve and assert projectRoot before branch-safety logic
Centralize root resolution so helpers never receive empty strings
In CI, echo the workspace path before git-dependent steps to catch empty values early

When it happens

Trigger: Calling isOnDefaultBranch(undefined) or '' — typically an unset project root from config; also via Promise.all paths when the supplied root is empty string.

Common situations: Scripts checking 'safe to commit on main?' executed outside a configured project; pipelines where the workspace variable is empty; tests passing no fixture path.

Understand the failure class

Background: Missing required parameter errors: what 'X is required' and 'the required X param is missing' mean, and how to fix them — this error's family across 27 libraries.

Related errors

AI-assisted analysis of eyaltoledano/claude-task-master@c0c98d367c (2026-08-29). Data as JSON: /api/errors/c40659bcddf3de93. Report an issue: GitHub.