S3: Minor cleanups

s3/src/main/scala/akka/stream/alpakka/s3/S3Attributes.scala

@@ -24,7 +24,7 @@ object S3Attributes {
 
 final class S3SettingsPath private (val path: String) extends Attribute
 object S3SettingsPath {
-  val Default = S3SettingsPath(S3Settings.ConfigPath)
+  val Default: S3SettingsPath = S3SettingsPath(S3Settings.ConfigPath)
 
   def apply(path: String) = new S3SettingsPath(path)
 }

s3/src/main/scala/akka/stream/alpakka/s3/S3Ext.scala

@@ -15,7 +15,7 @@ final class S3Ext private (sys: ExtendedActorSystem) extends Extension {
 }
 
 object S3Ext extends ExtensionId[S3Ext] with ExtensionIdProvider {
-  override def lookup = S3Ext
+  override def lookup: S3Ext.type = S3Ext
   override def createExtension(system: ExtendedActorSystem) = new S3Ext(system)
 
   /**

s3/src/main/scala/akka/stream/alpakka/s3/S3Headers.scala

@@ -26,7 +26,7 @@ final class MetaHeaders private (val metaHeaders: Map[String, String]) {
     metaHeaders = metaHeaders
   )
 
-  override def toString =
+  override def toString: String =
     "MetaHeaders(" +
     s"metaHeaders=$metaHeaders," +
     ")"
@@ -45,7 +45,7 @@ object MetaHeaders {
   def apply(metaHeaders: Map[String, String]) =
     new MetaHeaders(metaHeaders)
 
-  def create(metaHeaders: java.util.Map[String, String]) =
+  def create(metaHeaders: java.util.Map[String, String]): MetaHeaders =
     apply(metaHeaders.asScala.toMap)
 }
 
@@ -70,13 +70,13 @@ final class S3Headers private (val cannedAcl: Option[CannedAcl] = None,
   @InternalApi private[s3] def headersFor(request: S3Request) =
     headers ++ serverSideEncryption.toIndexedSeq.flatMap(_.headersFor(request))
 
-  def withCannedAcl(cannedAcl: CannedAcl) = copy(cannedAcl = Some(cannedAcl))
-  def withMetaHeaders(metaHeaders: MetaHeaders) = copy(metaHeaders = Some(metaHeaders))
-  def withStorageClass(storageClass: StorageClass) = copy(storageClass = Some(storageClass))
-  def withCustomHeaders(customHeaders: Map[String, String]) = copy(customHeaders = customHeaders)
-  def withServerSideEncryption(serverSideEncryption: ServerSideEncryption) =
+  def withCannedAcl(cannedAcl: CannedAcl): S3Headers = copy(cannedAcl = Some(cannedAcl))
+  def withMetaHeaders(metaHeaders: MetaHeaders): S3Headers = copy(metaHeaders = Some(metaHeaders))
+  def withStorageClass(storageClass: StorageClass): S3Headers = copy(storageClass = Some(storageClass))
+  def withCustomHeaders(customHeaders: Map[String, String]): S3Headers = copy(customHeaders = customHeaders)
+  def withServerSideEncryption(serverSideEncryption: ServerSideEncryption): S3Headers =
     copy(serverSideEncryption = Some(serverSideEncryption))
-  def withOptionalServerSideEncryption(serverSideEncryption: Option[ServerSideEncryption]) =
+  def withOptionalServerSideEncryption(serverSideEncryption: Option[ServerSideEncryption]): S3Headers =
     copy(serverSideEncryption = serverSideEncryption)
 
   private def copy(
@@ -93,7 +93,7 @@ final class S3Headers private (val cannedAcl: Option[CannedAcl] = None,
     serverSideEncryption = serverSideEncryption
   )
 
-  override def toString =
+  override def toString: String =
     "S3Headers(" +
     s"cannedAcl=$cannedAcl," +
     s"metaHeaders=$metaHeaders," +
@@ -126,10 +126,10 @@ object S3Headers {
    */
   val empty: S3Headers = new S3Headers()
 
-  def apply() = empty
+  def apply(): S3Headers = empty
 
   /**
    * Java Api
    */
-  def create() = empty
+  def create(): S3Headers = empty
 }

s3/src/main/scala/akka/stream/alpakka/s3/headers/ServerSideEncryption.scala

@@ -43,7 +43,7 @@ final class AES256 private[headers] () extends ServerSideEncryption {
     case _ => Nil
   }
 
-  override def toString =
+  override def toString: String =
     "ServerSideEncryption.AES256(" +
     ")"
 
@@ -78,8 +78,8 @@ final class KMS private[headers] (val keyId: String, val context: Option[String]
     case _ => Nil
   }
 
-  def withKeyId(keyId: String) = copy(keyId = keyId)
-  def withContext(context: String) = copy(context = Some(context))
+  def withKeyId(keyId: String): KMS = copy(keyId = keyId)
+  def withContext(context: String): KMS = copy(context = Some(context))
 
   private def copy(
       keyId: String = keyId,
@@ -89,7 +89,7 @@ final class KMS private[headers] (val keyId: String, val context: Option[String]
     context = context
   )
 
-  override def toString =
+  override def toString: String =
     "ServerSideEncryption.KMS(" +
     s"keyId=$keyId," +
     s"context=$context" +
@@ -143,8 +143,8 @@ final class CustomerKeys private[headers] (val key: String, val md5: Option[Stri
     case _ => Nil
   }
 
-  def withKey(key: String) = copy(key = key)
-  def withMd5(md5: String) = copy(md5 = Some(md5))
+  def withKey(key: String): CustomerKeys = copy(key = key)
+  def withMd5(md5: String): CustomerKeys = copy(md5 = Some(md5))
 
   private def copy(
       key: String = key,
@@ -154,7 +154,7 @@ final class CustomerKeys private[headers] (val key: String, val md5: Option[Stri
     md5 = md5
   )
 
-  override def toString =
+  override def toString: String =
     "ServerSideEncryption.CustomerKeys(" +
     s"key=$key," +
     s"md5=$md5" +

s3/src/main/scala/akka/stream/alpakka/s3/impl/HttpRequests.scala

@@ -207,7 +207,7 @@ import scala.concurrent.{ExecutionContext, Future}
     val range = copyPartition.range
     val source = copyPartition.sourceLocation.validate(conf)
     val encodedKey = URLEncoder.encode(source.key, StandardCharsets.UTF_8.toString)
-    val sourceHeaderValuePrefix = s"/${source.bucket}/${encodedKey}"
+    val sourceHeaderValuePrefix = s"/${source.bucket}/$encodedKey"
     val sourceHeaderValue = sourceVersionId
       .map(versionId => s"$sourceHeaderValuePrefix?versionId=$versionId")
       .getOrElse(sourceHeaderValuePrefix)

s3/src/main/scala/akka/stream/alpakka/s3/impl/auth/package.scala

@@ -13,12 +13,12 @@ import akka.util.ByteString
 
 package object auth {
 
-  private val Digits = "0123456789abcdef".toCharArray()
+  private val Digits = "0123456789abcdef".toCharArray
 
   @InternalApi private[impl] def encodeHex(bytes: Array[Byte]): String = {
     val length = bytes.length
     val out = new Array[Char](length * 2)
-    for (i <- 0 to length - 1) {
+    for (i <- 0 until length) {
       val b = bytes(i)
       out(i * 2) = Digits((b >> 4) & 0xF)
       out(i * 2 + 1) = Digits(b & 0xF)

s3/src/main/scala/akka/stream/alpakka/s3/model.scala

@@ -59,7 +59,7 @@ final class MultipartUploadResult private (
     versionId = versionId
   )
 
-  override def toString =
+  override def toString: String =
     "MultipartUploadResult(" +
     s"location=$location," +
     s"bucket=$bucket," +
@@ -412,10 +412,10 @@ final class FailedUpload private (
 
 object FailedUpload {
 
-  def apply(reasons: Seq[Throwable]) = new FailedUpload(reasons)
+  def apply(reasons: Seq[Throwable]): FailedUpload = new FailedUpload(reasons)
 
   /** Java API */
-  def create(reasons: Seq[Throwable]) = FailedUpload(reasons)
+  def create(reasons: Seq[Throwable]): FailedUpload = FailedUpload(reasons)
 }
 
 /**
@@ -476,7 +476,7 @@ final class ListBucketResultContents private (
     storageClass = storageClass
   )
 
-  override def toString =
+  override def toString: String =
     "ListBucketResultContents(" +
     s"bucketName=$bucketName," +
     s"key=$key," +
@@ -564,7 +564,7 @@ final class ListBucketResultCommonPrefixes private (
     prefix = prefix
   )
 
-  override def toString =
+  override def toString: String =
     "ListBucketResultCommonPrefixes(" +
     s"bucketName=$bucketName," +
     s"prefix=$prefix" +

s3/src/main/scala/akka/stream/alpakka/s3/settings.scala

@@ -44,7 +44,7 @@ final class Proxy private (
   private def copy(host: String = host, port: Int = port, scheme: String = scheme): Proxy =
     new Proxy(host = host, port = port, scheme = scheme)
 
-  override def toString =
+  override def toString: String =
     "Proxy(" +
     s"host=$host," +
     s"port=$port," +
@@ -82,13 +82,13 @@ final class ForwardProxyCredentials private (val username: String, val password:
   /** Java API */
   def getPassword: String = password
 
-  def withUsername(username: String) = copy(username = username)
-  def withPassword(password: String) = copy(password = password)
+  def withUsername(username: String): ForwardProxyCredentials = copy(username = username)
+  def withPassword(password: String): ForwardProxyCredentials = copy(password = password)
 
   private def copy(username: String = username, password: String = password) =
     new ForwardProxyCredentials(username, password)
 
-  override def toString =
+  override def toString: String =
     "ForwardProxyCredentials(" +
     s"username=$username," +
     s"password=******" +
@@ -137,18 +137,18 @@ final class ForwardProxy private (val scheme: String,
   /** Java API */
   def getCredentials: java.util.Optional[ForwardProxyCredentials] = credentials.asJava
 
-  def withScheme(value: String) = copy(scheme = value)
-  def withHost(host: String) = copy(host = host)
-  def withPort(port: Int) = copy(port = port)
-  def withCredentials(credentials: ForwardProxyCredentials) = copy(credentials = Option(credentials))
+  def withScheme(value: String): ForwardProxy = copy(scheme = value)
+  def withHost(host: String): ForwardProxy = copy(host = host)
+  def withPort(port: Int): ForwardProxy = copy(port = port)
+  def withCredentials(credentials: ForwardProxyCredentials): ForwardProxy = copy(credentials = Option(credentials))
 
   private def copy(scheme: String = scheme,
                    host: String = host,
                    port: Int = port,
                    credentials: Option[ForwardProxyCredentials] = credentials) =
     new ForwardProxy(scheme, host, port, credentials)
 
-  override def toString =
+  override def toString: String =
     "ForwardProxy(" +
     s"scheme=$scheme," +
     s"host=$host," +
@@ -175,7 +175,7 @@ object ForwardProxy {
     new ForwardProxy("https", host, port, credentials)
 
   /** Java API */
-  def create(host: String, port: Int, credentials: Optional[ForwardProxyCredentials]) =
+  def create(host: String, port: Int, credentials: Optional[ForwardProxyCredentials]): ForwardProxy =
     apply(host, port, credentials.asScala)
 
   /** Use an HTTP proxy. */
@@ -316,7 +316,7 @@ final class MultipartUploadSettings private (val retrySettings: RetrySettings) {
   /** Java API */
   def getRetrySettings: RetrySettings = retrySettings
 
-  def withRetrySettings(value: RetrySettings) = MultipartUploadSettings(value)
+  def withRetrySettings(value: RetrySettings): MultipartUploadSettings = MultipartUploadSettings(value)
 
   override def toString =
     s"MultipartUploadSettings(retrySettings=$retrySettings)"
@@ -433,7 +433,7 @@ final class S3Settings private (
     multipartUploadSettings
   )
 
-  override def toString =
+  override def toString: String =
     "S3Settings(" +
     s"bufferType=$bufferType," +
     s"credentialsProvider=$credentialsProvider," +