Function can

packages/dotcom-shared/src/roles.ts:36–41

(role: string | null | undefined, capability: Capability)

 * throwing, so callers never have to validate it first.
 */
export function can(role: string | null | undefined, capability: Capability): boolean {
	if (!isRole(role)) return false
	// `satisfies` narrows each array to a tuple of its own literals, so the cast
	// widens it back to the full Capability union for `includes`.
	return (roles[role] as readonly Capability[]).includes(capability)
}

/** Whether a string is a known role name. */
export function isRole(role: string | null | undefined): role is Role {