Mapping(0x0233, 0x0239, TYPE_VALID, ByteString.EMPTY),
      Mapping(0x023a, 0x023a, TYPE_MAPPED, "b".encodeUtf8()),
    )
  }

  @Test fun simplifyDoesNotCombineWhenMappedTargetsAreDifferent() {
    assertThat(
      mergeAdjacentRanges(
        listOf(
          Mapping(0x0041, 0x0041, TYPE_MAPPED, "a".encodeUtf8()),
          Mapping(0x0042, 0x0042, TYPE_MAPPED, "b".encodeUtf8()),
        ),

      )
  }

  return result
}

internal fun canonicalizeType(type: Int): Int {
  return when (type) {
    TYPE_IGNORED -> TYPE_IGNORED

    TYPE_MAPPED,
    TYPE_DISALLOWED_STD3_MAPPED,
    -> TYPE_MAPPED

    TYPE_DEVIATION,
    TYPE_DISALLOWED_STD3_VALID,
    TYPE_VALID,
    -> TYPE_VALID

    TYPE_DISALLOWED -> TYPE_DISALLOWED

    require(index in mappings.indices) { "unexpected code point: $codePoint" }

    val mapping = mappings[index]
    var result = true

    when (mapping.type) {
      TYPE_IGNORED -> Unit
      TYPE_MAPPED, TYPE_DISALLOWED_STD3_MAPPED -> {
        sink.write(mapping.mappedTo)
      }

      TYPE_DEVIATION, TYPE_DISALLOWED_STD3_VALID, TYPE_VALID -> {
        sink.writeUtf8CodePoint(codePoint)
      }