Added getAs for QueryParams

zio-http/src/main/scala/zio/http/QueryParams.scala

@@ -18,9 +18,10 @@ package zio.http
 
 import java.nio.charset.Charset
 
-import zio.Chunk
+import zio.{Chunk, NonEmptyChunk}
 
 import zio.http.Charsets
+import zio.http.codec.{HttpCodecError, TextCodec}
 import zio.http.internal.QueryParamEncoding
 
 /**
@@ -88,25 +89,62 @@ final case class QueryParams(map: Map[String, Chunk[String]]) {
    */
   def getAll(key: String): Option[Chunk[String]] = map.get(key)
 
+  /**
+   * Retrieves all typed query parameter values having the specified name.
+   */
+  def getAllAs[A](key: String)(implicit codec: TextCodec[A]): Either[QueryParamsError, Chunk[A]] =
+    map.get(key) match {
+      case Some(params) =>
+        params
+          .map(param => codec.decode(param).toRight(QueryParamsError.MalformedQueryParam(key, param, codec)))
+          .partitionMap(identity) match {
+          case (errors, _) if errors.nonEmpty => Left(QueryParamsError.MultiMalformedQueryParam(errors))
+          case (_, typedParams)               => Right(typedParams)
+        }
+      case None         => Left(QueryParamsError.MissingQueryParam(key))
+    }
+
   /**
    * Retrieves the first query parameter value having the specified name.
    */
   def get(key: String): Option[String] = getAll(key).flatMap(_.headOption)
 
+  /**
+   * Retrieves the first typed query parameter value having the specified name.
+   */
+  def getAs[A](key: String)(implicit codec: TextCodec[A]): Either[QueryParamsError, A] = for {
+    param      <- get(key).toRight(QueryParamsError.MissingQueryParam(key))
+    typedParam <- codec.decode(param).toRight(QueryParamsError.MalformedQueryParam(key, param, codec))
+  } yield typedParam
+
   /**
    * Retrieves all query parameter values having the specified name, or else
    * uses the default iterable.
    */
   def getAllOrElse(key: String, default: => Iterable[String]): Chunk[String] =
     getAll(key).getOrElse(Chunk.fromIterable(default))
 
+  /**
+   * Retrieves all query parameter values having the specified name, or else
+   * uses the default iterable.
+   */
+  def getAllAsOrElse[A](key: String, default: => Iterable[A])(implicit codec: TextCodec[A]): Chunk[A] =
+    getAllAs[A](key).getOrElse(Chunk.fromIterable(default))
+
   /**
    * Retrieves the first query parameter value having the specified name, or
    * else uses the default value.
    */
   def getOrElse(key: String, default: => String): String =
     get(key).getOrElse(default)
 
+  /**
+   * Retrieves the first typed query parameter value having the specified name,
+   * or else uses the default value.
+   */
+  def getAsOrElse[A](key: String, default: => A)(implicit codec: TextCodec[A]): A =
+    getAs[A](key).getOrElse(default)
+
   override def hashCode: Int = normalize.map.hashCode
 
   /**

zio-http/src/main/scala/zio/http/QueryParamsError.scala

@@ -0,0 +1,44 @@
+/*
+ * Copyright 2021 - 2023 Sporta Technologies PVT LTD & the ZIO HTTP contributors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package zio.http
+
+import java.nio.charset.Charset
+
+import scala.util.control.NoStackTrace
+
+import zio.Chunk
+
+import zio.http.codec.TextCodec
+import zio.http.internal.QueryParamEncoding
+
+sealed trait QueryParamsError extends Exception with NoStackTrace {
+  override def getMessage(): String = message
+  def message: String
+}
+object QueryParamsError {
+  final case class MissingQueryParam(queryParamName: String) extends QueryParamsError {
+    def message = s"Missing query parameter with name $queryParamName"
+  }
+
+  final case class MalformedQueryParam(name: String, value: String, codec: TextCodec[_]) extends QueryParamsError {
+    def message = s"Unable to decode query parameter with name $name and value $value using $codec"
+  }
+
+  final case class MultiMalformedQueryParam(chunk: Chunk[MalformedQueryParam]) extends QueryParamsError {
+    def message: String = chunk.map(_.getMessage()).mkString("; ")
+  }
+}

zio-http/src/test/scala/zio/http/QueryParamsSpec.scala

@@ -236,10 +236,39 @@ object QueryParamsSpec extends ZIOHttpSpec {
           val default     = "default"
           val unknown     = "non-existent"
           val queryParams = QueryParams(name -> "a", name -> "b")
-          assertTrue(queryParams.get(name).get == "a") &&
-          assertTrue(queryParams.getOrElse(unknown, default) == default) &&
-          assertTrue(queryParams.getAll(name).get.length == 2) &&
-          assertTrue(queryParams.getAllOrElse(unknown, Chunk(default)).length == 1)
+          assertTrue(
+            queryParams.get(name).get == "a",
+            queryParams.get(unknown).isEmpty,
+            queryParams.getOrElse(name, default) == "a",
+            queryParams.getOrElse(unknown, default) == default,
+            queryParams.getAll(name).get.length == 2,
+            queryParams.getAll(unknown).isEmpty,
+            queryParams.getAllOrElse(name, Chunk(default)).length == 2,
+            queryParams.getAllOrElse(unknown, Chunk(default)).length == 1,
+          )
+        },
+      ),
+      suite("getAs - getAllAs")(
+        test("success") {
+          val typed        = "typed"
+          val default      = 3
+          val invalidTyped = "invalidTyped"
+          val unknown      = "non-existent"
+          val queryParams  = QueryParams(typed -> "1", typed -> "2", invalidTyped -> "str")
+          assertTrue(
+            queryParams.getAs[Int](typed) == Right(1),
+            queryParams.getAs[Int](invalidTyped).isLeft,
+            queryParams.getAs[Int](unknown).isLeft,
+            queryParams.getAsOrElse[Int](typed, default) == 1,
+            queryParams.getAsOrElse[Int](invalidTyped, default) == default,
+            queryParams.getAsOrElse[Int](unknown, default) == default,
+            queryParams.getAllAs[Int](typed).map(_.length) == Right(2),
+            queryParams.getAllAs[Int](invalidTyped).isLeft,
+            queryParams.getAllAs[Int](unknown).isLeft,
+            queryParams.getAllAsOrElse[Int](typed, Chunk(default)).length == 2,
+            queryParams.getAllAsOrElse[Int](invalidTyped, Chunk(default)).length == 1,
+            queryParams.getAllAsOrElse[Int](unknown, Chunk(default)).length == 1,
+          )
         },
       ),
       suite("encode - decode")(