export type BankingInstitution = { bic?: unknown [key: string]: unknown } export const findBankInstitutionByBic = ( institutions: unknown, bic: string, ): BankingInstitution | null => { if (!Array.isArray(institutions)) return null const normalizedBic = bic.trim().toUpperCase() if (!normalizedBic) return null const institution = institutions.find((candidate): candidate is BankingInstitution => { if (!candidate || typeof candidate !== "object") return false const candidateBic = (candidate as BankingInstitution).bic return typeof candidateBic === "string" && candidateBic.trim().toUpperCase() === normalizedBic }) return institution || null }