TypeScript Consumer Pattern

TypeScript Consumer Pattern

A TypeScript consumer should separate parsing from the application decision.

type KnownStatus =
  | "PASS"
  | "FAIL"
  | "INCOMPLETE"
  | "UNKNOWN";

type VerificationResult = {
  status: KnownStatus;
  artifactId?: string;
  raw: Record<string, unknown>;
};

function parseVerificationResult(
  payload: Record<string, unknown>
): VerificationResult {
  const candidate = payload.status;

  const known: KnownStatus[] = [
    "PASS",
    "FAIL",
    "INCOMPLETE",
    "UNKNOWN",
  ];

  const status: KnownStatus =
    typeof candidate === "string" &&
    known.includes(candidate as KnownStatus)
      ? (candidate as KnownStatus)
      : "UNKNOWN";

  return {
    status,
    artifactId:
      typeof payload.artifact_id === "string"
        ? payload.artifact_id
        : undefined,
    raw: payload,
  };
}

function mayAccept(
  result: VerificationResult
): boolean {
  return result.status === "PASS";
}

Integration rule

Do not let an unknown enum value fall through to a default success path.

When the authoritative DigiEmu contract changes, update the parser and tests before enabling the new state in production.