AcmeCompanyApi1.ts

class AcmeCompanyApi implements CompanyApi {

    constructor(
        private readonly forGettingCauses: ForGettingCauses,
        private readonly forOpeningClaim: ForOpeningClaim,
        private readonly authTokenRetriever: AuthTokenRetriever) {
    }

    async open(claim: Claim): Promise<OpeningResult> {
        try {
            const token = await this.authTokenRetriever.retrieveToken();
            const causes = await this.forGettingCauses.getAllFor(claim, token);
            const cause = this.findCauseInClaim(causes, claim);
            const referenceInCompany = await this.forOpeningClaim.open(claim, cause, token);
            return OpeningResult.successful(referenceInCompany, claim);
        } catch (e) {
            if (e instanceof CannotRetrieveTokenError) {
                return OpeningResult.failed(claim, 'Acme API: failure retrieving token');
            }
            if (e instanceof CannotGetCausesError) {
                return OpeningResult.failed(claim, 'Acme API: failure getting claim causes');
            }
            if (e instanceof CannotOpenClaimError) {
                return OpeningResult.failed(
                    claim, `Acme API: cannot open claim ${claim.id()}`
                );
            }
            if (e instanceof CannotFindMatchingCauseError) {
                return OpeningResult.failed(
                    claim, `Acme API: cannot find cause for claim ${claim.id()}`
                );
            }
            return OpeningResult.failed(
                claim, `Acme API: ${e.message}`
            );
        }
    }

    private findCauseInClaim(causes: Cause[], claim: Claim): Cause {
        let foundCause = causes.find((c) => c.causeCode === claim.causeCode());
        if (!foundCause) {
            throw new CannotFindMatchingCauseError();
        }
        return foundCause;
    }
}