js-ceramic key-did-resolver/secp256r.ts null errors

gistfile1.txt

test('public key as null', () => {
  const inputPublicKeyHex = null;
  const base64urlPoint = mapper.publicKeyToXY(inputPublicKeyHex);
  //  expect(base64urlPoint).toEqual(output);
 });

triggers an error:

  ● public key as null

    TypeError: Cannot read property 'slice' of null

      77 |
      78 | export function publicKeyHexToUint8ArrayPointPair(publicKeyHex: string) {
    > 79 |     const xHex = publicKeyHex.slice(0,publicKeyHex.length/2);
         |                               ^
      80 |     const yHex = publicKeyHex.slice(publicKeyHex.length/2,publicKeyHex.length);
      81 |     const xOctet = u8a.fromString(xHex,'base16');
      82 |     const yOctet = u8a.fromString(yHex,'base16');

      at publicKeyHexToUint8ArrayPointPair (src/secp256r1.ts:79:31)
      at Object.publicKeyToXY (src/secp256r1.ts:72:24)
      at Object.<anonymous> (src/__tests__/secp256r1.test.ts:62:33)



Note: publicKeyToXY(publicKeyHex: string) first calls publicKeyHexToUint8ArrayPointPair(publicKeyHex: string)


export function publicKeyHexToUint8ArrayPointPair(publicKeyHex: string) {
    const xHex = publicKeyHex.slice(0,publicKeyHex.length/2);    // BREAKS ON NULL
    const yHex = publicKeyHex.slice(publicKeyHex.length/2,publicKeyHex.length);  // BREAKS ON NULL
    const xOctet = u8a.fromString(xHex,'base16'); // BREAKS ON NULL
    const yOctet = u8a.fromString(yHex,'base16'); // BREAKS ON NULL
    return { xOctet, yOctet };
}


This produces an error:

 const xOctet = u8a.fromString(null,'base16');

This produces an error:

 const xOctet = u8a.fromString(xHex,'base16'); 



publicKeyIntToXY(ecpoint: BigIntPoint) first calls publicKeyIntToUint8ArrayPointPair(ecpoint: BigIntPoint)


test('convert a public key x,y as nulls', () => {
   const ecpoint = {
          x: null,
          y: null
   };

   const u8aPoint = mapper.publicKeyIntToUint8ArrayPointPair(ecpoint);
});

triggers an error:

  ● convert a public key x,y as nulls

    TypeError: Cannot read property 'toString' of null

      92 |
      93 | export function publicKeyIntToUint8ArrayPointPair(ecpoint: BigIntPoint) {
    > 94 |   const xHex = (ecpoint.x).toString();
         |                            ^
      95 |   const yHex = (ecpoint.y).toString();
      96 |   const xOctet = u8a.fromString(xHex,'base10');
      97 |   const yOctet = u8a.fromString(yHex,'base10');

      at Object.publicKeyIntToUint8ArrayPointPair (src/secp256r1.ts:94:28)
      at Object.<anonymous> (src/__tests__/secp256r1.test.ts:67:28)