isAscii() -> lowercase(Locale.US) // This is an ASCII string.
      else -> this
    }
  }

  /** Returns true if the [String] is ASCII encoded (0-127). */
  private fun String.isAscii() = length == utf8Size().toInt()

  /**
   * Returns true if [hostname] matches the domain name [pattern].
   *
   * @param hostname lower-case host name.
   * @param pattern domain name pattern from certificate. May be a wildcard pattern such as

    fun buildIfSupported(): Platform? {
      val jvmVersion = System.getProperty("java.specification.version", "unknown")
      try {
        // 1.8, 9, 10, 11, 12 etc
        val version = jvmVersion.toInt()
        if (version >= 9) return null
      } catch (_: NumberFormatException) {
        // expected on >= JDK 9
      }

      // Find Jetty's ALPN extension for OpenJDK.
      try {

        "-Xjvm-default=all",
      )
    }
  }

  val platform = System.getProperty("okhttp.platform", "jdk9")
  val testJavaVersion = System.getProperty("test.java.version", "21").toInt()

  val testRuntimeOnly: Configuration by configurations.getting
  dependencies {
    testRuntimeOnly(rootProject.libs.junit.jupiter.engine)
    testRuntimeOnly(rootProject.libs.junit.vintage.engine)
  }

  val ideaVersionString = System.getProperty("idea.version") ?: return false

  return try {
    val (major, minor, _) = ideaVersionString.split(".", limit = 3)
    KotlinVersion(major.toInt(), minor.toInt()) < KotlinVersion(2023, 2)
  } catch (e: Exception) {
    false // Unknown version, presumably compatible.
  }

plugins {
  kotlin("jvm")
}

val platform = System.getProperty("okhttp.platform", "jdk9")
val testJavaVersion = System.getProperty("test.java.version", "21").toInt()

tasks.withType<Test> {
  useJUnitPlatform()
  onlyIf("By default not in CI") {
    System.getenv("CI") == null
      || (project.hasProperty("containerTests") && project.property("containerTests").toString().toBoolean())
  }

  jvmArgs(
    "-Dokhttp.platform=$platform",

          // Byte xor is experimental in Kotlin so we coerce bytes to int, xor them
          // and convert back to byte.
          val bufferInt: Int = buffer[i].toInt()
          val keyInt: Int = key[keyIndex].toInt()
          buffer[i] = (bufferInt xor keyInt).toByte()

          i++
          keyIndex++
        }
      }
    } while (cursor.next() != -1)
  }

            'r'.code -> append('\r')
            's'.code -> append(' ')
            't'.code -> append('\t')
            'f'.code -> append('\u000c')
            'u'.code -> append(buffer.readUtf8(4).toInt(16).toChar())
            else -> throw IllegalArgumentException("unexpected escape character in $s")
          }
        }
      }
    }
  }

    val flags = buf.readShort().toInt() and 0xffff
    require(flags shr 15 != 0) { "not a response" }

    val responseCode = flags and 0xf

    if (responseCode == NXDOMAIN) {
      throw UnknownHostException("$hostname: NXDOMAIN")
    } else if (responseCode == SERVFAIL) {
      throw UnknownHostException("$hostname: SERVFAIL")
    }

    val questionCount = buf.readShort().toInt() and 0xffff

  override fun hashCode(): Int {
    var result = 0
    result = 31 * result + tagClass
    result = 31 * result + tag.toInt()
    result = 31 * result + (if (constructed) 0 else 1)
    result = 31 * result + length.toInt()
    return result
  }

  override fun toString(): String = "$tagClass/$tag"

  companion object {
    const val TAG_CLASS_UNIVERSAL = 0b0000_0000

      } else {
        encodedCharBuffer.writeString(input, i, i + Character.charCount(codePoint), charset)
      }

      while (!encodedCharBuffer.exhausted()) {
        val b = encodedCharBuffer.readByte().toInt() and 0xff
        writeByte('%'.code)
        writeByte(HEX_DIGITS[b shr 4 and 0xf].code)
        writeByte(HEX_DIGITS[b and 0xf].code)
      }
    } else {