thin-wrapper-functions

a function that only renames parameters or forwards to another

Agent checkadvisory by defaultbasecode

The argument

Anti-Patterns to Avoid

Thin Wrapper Functions

Don't create functions that only rename parameters or forward to another function:

// ❌ adds nothing but indirection
export const buildBrowserLabel = ({ browser, browserVersion }) =>
	buildVersionedLabel({ name: browser, version: browserVersion });

// ✅ call the underlying function directly at the call site

A wrapper IS justified when it adds real validation/transformation, meaningfully simplifies a complex API, or handles errors/defaults.

Delegation to a held collaborator is not a thin wrapper

A class that holds a collaborator instead of extending one — the remedy the composition-over-inheritance rule requires — reaches it through one-line methods that forward unchanged. Those methods are the seam that rule asks for, not indirection to delete:

// ✅ the composition remedy: the sharing is visible at the seam
export class RefactorRun {
	private readonly runState: RunState;

	update({ patch }: { patch: Partial<RunManifest> }): Promise<void> {
		return this.runState.update({ patch });
	}
}

Deleting them means publishing the held value so callers can reach through it, and a caller that can reach through it can also step around a sibling method that adds something — a timer, a counter, a progress line — on the same call. The forward is what keeps the class's surface the only way in.

This carve-out covers a class delegating to something it holds, and nothing else. A free function that only forwards to another free function is still a thin wrapper.

The proof

fail

import { buildVersionedLabel } from './buildVersionedLabel';

interface Params {
	browser: string;
	browserVersion: string;
}

// Adds nothing but indirection: no validation, no defaults, no error handling —
// only two parameters renamed on their way through.
export const buildBrowserLabel = ({ browser, browserVersion }: Params): string =>
	buildVersionedLabel({ name: browser, version: browserVersion });

pass

import { buildVersionedLabel } from '../common/utils/buildVersionedLabel';

interface Params {
	browser: string;
	browserVersion: string;
}

// The call site does the renaming, so there is no second function to keep in
// step with the first.
export const getBrowserBadge = ({ browser, browserVersion }: Params): string =>
	`<span>${buildVersionedLabel({ name: browser, version: browserVersion })}</span>`;

Turn it down

Both lines go in your lightsout.config.json.

"standards-checks": { "thin-wrapper-functions": "advisory" }

"standards-checks": { "thin-wrapper-functions": "off" }