message: Fail tests if required exceptions are not thrown.
diff: @@ -74,6 +74,7 @@ if ((Environment.IS_WEBCRYPTO_AVAILABLE)) {
  async testType() {
  try {
  await AesGcm.newInstance('blah');
  + fail('expected AesGcm.newInstance to fail');
  } catch (e) {
  assertEquals(
  'CustomError: input must be a non null Uint8Array', e.toString());
  @@ -82,24 +83,28 @@ if ((Environment.IS_WEBCRYPTO_AVAILABLE)) {
  const aead = await AesGcm.newInstance(Random.randBytes(16));
  try {
  await aead.encrypt('blah');
  + fail('expected aead.encrypt to fail');
  } catch (e) {
  assertEquals(
  'CustomError: input must be a non null Uint8Array', e.toString());
  }
  try {
  await aead.encrypt(Random.randBytes(20), 'blah');
  + fail('expected aead.encrypt to fail');
  } catch (e) {
  assertEquals(
  'CustomError: input must be a non null Uint8Array', e.toString());
  }
  try {
  await aead.decrypt('blah');
  + fail('expected aead.decrypt to fail');
  } catch (e) {
  assertEquals(
  'CustomError: input must be a non null Uint8Array', e.toString());
  }
  try {
  await aead.decrypt(Random.randBytes(32), 'blah');
  + fail('expected aead.decrypt to fail');
  } catch (e) {
  assertEquals(
  'CustomError: input must be a non null Uint8Array', e.toString());
  @@ -117,6 +122,7 @@ if ((Environment.IS_WEBCRYPTO_AVAILABLE)) {
  c1[i] = (c1[i] ^ (1 << j));
  try {
  await aead.decrypt(c1, aad);
  + fail('expected aead.decrypt to fail');
  } catch (e) {
  assertTrue(e.toString().startsWith('CustomError: OperationError'));
  }
  @@ -135,6 +141,7 @@ if ((Environment.IS_WEBCRYPTO_AVAILABLE)) {
  aad1[i] = (aad1[i] ^ (1 << j));
  try {
  await aead.decrypt(ciphertext, aad1);
  + fail('expected aead.decrypt to fail');
  } catch (e) {
  assertTrue(e.toString().startsWith('CustomError: OperationError'));
  }
  @@ -151,6 +158,7 @@ if ((Environment.IS_WEBCRYPTO_AVAILABLE)) {
  const c1 = new Uint8Array(ciphertext.buffer, 0, ciphertext.length - i);
  try {
  await aead.decrypt(c1, aad);
  + fail('expected aead.decrypt to fail');
  } catch (e) {
  if (c1.length < 12 /* iv */ + 16 /* tag */) {
  assertEquals('CustomError: ciphertext too short', e.toString());
  