esr-code-line/src/index.test.ts

A code line generator for orange payment slips used in Switzerland

import {
  codeLine,
  checkDigit,
  attachCheckDigit,
  toSubscriberNumber,
  pad,
} from "./index";

test("Pads prices in CHF to the left with zeros.", () => {
  const codeRequiresPaddingEightDigits = pad("1", 8);
  expect(codeRequiresPaddingEightDigits).toBe("00000001");

  const requiresPaddingToTwoDigits = pad("5", 2);
  expect(requiresPaddingToTwoDigits).toBe("05");

  const codeExactRequiredLength = pad("12345678", 8);
  expect(codeExactRequiredLength).toBe("12345678");

  const codeOverRequiredLength = pad("0123456789", 8);
  expect(codeOverRequiredLength).toBe("0123456789");
});

test("Transforms a customer number to the code line value.", () => {
  // Value take from ISR Manual p. 24
  const r1 = toSubscriberNumber("01-162-8");
  expect(r1).toBe("010001628");

  const r2 = toSubscriberNumber("03-162-5");
  expect(r2).toBe("030001625");

  expect(() => {
    toSubscriberNumber("010001628");
  }).toThrow(TypeError);
});

test("Computes valid check digits.", () => {
  // Values taken from ISR Manual p. 26
  const shortCode = checkDigit("31");
  expect(shortCode).toBe(9);

  const shortCodeLeadingZero = checkDigit("04");
  expect(shortCodeLeadingZero).toBe(2);

  const longCode = checkDigit("210000044000");
  expect(longCode).toBe(1);

  const longCodeLeadingZero = checkDigit("010000394975");
  expect(longCodeLeadingZero).toBe(3);

  // Helper function
  const attachedCheckDigit = attachCheckDigit("04");
  expect(attachedCheckDigit).toBe("042");
});

test("Contains a valid check digit in the correct spot.", () => {
  // Values taken from ISR Manual p. 25
  const result = codeLine({
    slipType: "01",
    amountFrancsOrEuros: "3949",
    amountRappenOrCents: "75",
    referenceNumber: "12 00000 00000 23447 89432 16899",
    customerNumber: "01-162-8",
  });

  // check digit of slip type and amount is 3
  expect(result).toContain("0100003949753");
});

test("Assembles code in the correct order.", () => {
  const result = codeLine({
    slipType: "01",
    amountFrancsOrEuros: "3949",
    amountRappenOrCents: "75",
    referenceNumber: "12 00000 00000 23447 89432 16899",
    customerNumber: "01-162-8",
  });
  expect(result).toBe("0100003949753>120000000000234478943216899+ 010001628>");
});

test("Doesn't include price if zero or empty", () => {
  const priceZero = codeLine({
    slipType: "04",
    amountFrancsOrEuros: "0",
    amountRappenOrCents: "0",
    referenceNumber: "12 34567 89012 34567 89012 34567",
    customerNumber: "01-162-8",
  });
  expect(priceZero).toBe("042>123456789012345678901234567+ 010001628>");

  const priceEmpty = codeLine({
    slipType: "04",
    amountFrancsOrEuros: "",
    amountRappenOrCents: "",
    referenceNumber: "12 34567 89012 34567 89012 34567",
    customerNumber: "01-162-8",
  });
  expect(priceEmpty).toBe("042>123456789012345678901234567+ 010001628>");
});