Commit code for ticket 1542 Content-Encoding. (zio#1648)

* Commit code for ticket 1542 Content-Encoding.

* Commit code removing duplicate test case.

* Commit code moving the import statement to address the build error.

zio-http/src/main/scala/zio/http/model/headers/values/ContentEncoding.scala

@@ -0,0 +1,97 @@
+package zio.http.model.headers.values
+
+import zio.Chunk
+
+sealed trait ContentEncoding {
+ val encoding: String
+}
+
+object ContentEncoding {
+
+ /**
+ * InvalidEncoding is represented with ""
+ */
+ case object InvalidEncoding extends ContentEncoding {
+ override val encoding: String = ""
+ }
+
+ /**
+ * A format using the Brotli algorithm.
+ */
+ case object BrEncoding extends ContentEncoding {
+ override val encoding: String = "br"
+ }
+
+ /**
+ * A format using the Lempel-Ziv-Welch (LZW) algorithm. The value name was
+ * taken from the UNIX compress program, which implemented this algorithm.
+ * Like the compress program, which has disappeared from most UNIX
+ * distributions, this content-encoding is not used by many browsers today,
+ * partly because of a patent issue (it expired in 2003).
+ */
+ case object CompressEncoding extends ContentEncoding {
+ override val encoding: String = "compress"
+ }
+
+ /**
+ * Using the zlib structure (defined in RFC 1950) with the deflate compression
+ * algorithm (defined in RFC 1951).
+ */
+ case object DeflateEncoding extends ContentEncoding {
+ override val encoding: String = "deflate"
+ }
+
+ /**
+ * A format using the Lempel-Ziv coding (LZ77), with a 32-bit CRC. This is the
+ * original format of the UNIX gzip program. The HTTP/1.1 standard also
+ * recommends that the servers supporting this content-encoding should
+ * recognize x-gzip as an alias, for compatibility purposes.
+ */
+ case object GZipEncoding extends ContentEncoding {
+ override val encoding: String = "gzip"
+ }
+
+ /**
+ * Maintains a list of ContentEncoding values.
+ */
+ final case class MultipleEncodings(encodings: Chunk[ContentEncoding]) extends ContentEncoding {
+ override val encoding: String = encodings.map(_.encoding).mkString(",")
+ }
+
+ private def findEncoding(value: String): ContentEncoding = {
+ value.trim match {
+ case "br" => BrEncoding
+ case "compress" => CompressEncoding
+ case "deflate" => DeflateEncoding
+ case "gzip" => GZipEncoding
+ case _ => InvalidEncoding
+ }
+ }
+
+ /**
+ * @param value
+ * of string , seperated for multiple values
+ * @return
+ * ContentEncoding
+ *
+ * Note: This implementation ignores the invalid string that might occur in
+ * MultipleEncodings case.
+ */
+ def toContentEncoding(value: String): ContentEncoding = {
+ val array = value.split(",")
+ array.foldLeft[ContentEncoding](InvalidEncoding)((accum, elem) => {
+ val encoding = findEncoding(elem)
+ (accum, encoding) match {
+ case (InvalidEncoding, InvalidEncoding) => InvalidEncoding
+ case (InvalidEncoding, other) => other
+ case (MultipleEncodings(encodings), InvalidEncoding) => MultipleEncodings(encodings)
+ case (MultipleEncodings(encodings), other) => MultipleEncodings(encodings ++ Chunk(other))
+ case (other, InvalidEncoding) => other
+ case (other, other1) => MultipleEncodings(Chunk(other, other1))
+ }
+ })
+ }
+
+ def fromContentEncoding(value: ContentEncoding): String = value.encoding
+
+}

zio-http/src/test/scala/zio/http/internal/HttpGen.scala

@@ -290,4 +290,14 @@ object HttpGen {
  def connectionHeader: Gen[Any, Connection] =
  Gen.elements(Connection.Close, Connection.KeepAlive, Connection.InvalidConnection)
 
+ def allowContentEncodingSingleValue: Gen[Any, ContentEncoding] = Gen.fromIterable(
+ List(
+ ContentEncoding.BrEncoding,
+ ContentEncoding.CompressEncoding,
+ ContentEncoding.GZipEncoding,
+ ContentEncoding.MultipleEncodings(Chunk(ContentEncoding.BrEncoding, ContentEncoding.CompressEncoding)),
+ ContentEncoding.DeflateEncoding,
+ ContentEncoding.InvalidEncoding,
+ ),
+ )
 }

zio-http/src/test/scala/zio/http/model/headers/values/ContentEncodingSpec.scala

@@ -0,0 +1,57 @@
+package zio.http.model.headers.values
+
+import zio.http.internal.HttpGen
+import zio.http.model.headers.values.ContentEncoding.{InvalidEncoding, MultipleEncodings}
+import zio.test.{Spec, TestEnvironment, ZIOSpecDefault, assertTrue, check}
+import zio.{Chunk, Scope}
+
+object ContentEncodingSpec extends ZIOSpecDefault {
+ override def spec: Spec[TestEnvironment with Scope, Any] = suite("ContentEncoding suite")(
+ suite("ContentEncoding header value transformation should be symmetrical")(
+ test("gen single value") {
+ check(HttpGen.allowContentEncodingSingleValue) { value =>
+ assertTrue(ContentEncoding.toContentEncoding(ContentEncoding.fromContentEncoding(value)) == value)
+ }
+ },
+ test("single value") {
+ assertTrue(ContentEncoding.toContentEncoding("br") == ContentEncoding.BrEncoding) &&
+ assertTrue(ContentEncoding.toContentEncoding("compress") == ContentEncoding.CompressEncoding) &&
+ assertTrue(ContentEncoding.toContentEncoding("deflate") == ContentEncoding.DeflateEncoding) &&
+ assertTrue(
+ ContentEncoding.toContentEncoding("deflate, br, compress") == ContentEncoding.MultipleEncodings(
+ Chunk(ContentEncoding.DeflateEncoding, ContentEncoding.BrEncoding, ContentEncoding.CompressEncoding),
+ ),
+ ) &&
+ assertTrue(ContentEncoding.toContentEncoding("garbage") == ContentEncoding.InvalidEncoding)
+
+ },
+ test("edge cases") {
+ assertTrue(
+ ContentEncoding.toContentEncoding(
+ ContentEncoding.fromContentEncoding(MultipleEncodings(Chunk())),
+ ) == InvalidEncoding,
+ ) &&
+ assertTrue(
+ ContentEncoding.toContentEncoding(
+ ContentEncoding.fromContentEncoding(
+ MultipleEncodings(
+ Chunk(ContentEncoding.DeflateEncoding, ContentEncoding.BrEncoding, ContentEncoding.CompressEncoding),
+ ),
+ ),
+ ) == ContentEncoding.MultipleEncodings(
+ Chunk(ContentEncoding.DeflateEncoding, ContentEncoding.BrEncoding, ContentEncoding.CompressEncoding),
+ ),
+ ) &&
+ assertTrue(
+ ContentEncoding.toContentEncoding(
+ ContentEncoding.fromContentEncoding(
+ MultipleEncodings(
+ Chunk(ContentEncoding.DeflateEncoding),
+ ),
+ ),
+ ) == ContentEncoding.DeflateEncoding,
+ )
+ },
+ ),
+ )
+}