address nits

aws-runtime/aws-config/common/src/aws/sdk/kotlin/runtime/config/AbstractAwsSdkClientFactory.kt

@@ -66,9 +66,7 @@ public abstract class AbstractAwsSdkClientFactory<
                 config.retryStrategy = resolveRetryStrategy(profile = profile)
             }
 
-            if (block != null) {
-                config.apply(block)
-            }
+            block?.let(config::apply)
 
             config.logMode = config.logMode ?: ClientSettings.LogMode.resolve(platform = PlatformProvider.System)
             config.region = config.region ?: resolveRegion(profile = profile)

aws-runtime/aws-config/common/src/aws/sdk/kotlin/runtime/config/AwsSdkSetting.kt

@@ -171,6 +171,7 @@ public object AwsSdkSetting {
 /**
  * Resolves an endpoint url for a given service.
  */
+@InternalSdkApi
 public fun AwsSdkSetting.resolveEndpointUrl(
     provider: PlatformProvider,
     sysPropSuffix: String,

aws-runtime/aws-config/common/src/aws/sdk/kotlin/runtime/config/profile/AwsProfile.kt

@@ -143,7 +143,4 @@ internal fun AwsProfile.getUrlOrNull(key: String, subKey: String? = null): Url?
     }
 
 private fun buildKeyString(key: String, subKey: String? = null): String =
-    buildString {
-        append(key)
-        subKey?.let { append(".$it") }
-    }
+    listOfNotNull(key, subKey).joinToString(".")

codegen/smithy-aws-kotlin-codegen/src/main/kotlin/aws/sdk/kotlin/codegen/SdkIdTransform.kt

@@ -4,6 +4,8 @@
  */
 package aws.sdk.kotlin.codegen
 
+private val whitespaceRegex = Regex("\\s")
+
 /**
  * Implements a single standardized sdkId transform.
  */
@@ -56,4 +58,4 @@ object SdkIdTransform {
  */
 fun String.withTransform(transformer: SdkIdTransformer): String = transformer.transform(this)
 
-private fun String.replaceWhitespace(replacement: String) = replace(Regex("\\s"), replacement)
+private fun String.replaceWhitespace(replacement: String) = replace(whitespaceRegex, replacement)

codegen/smithy-aws-kotlin-codegen/src/main/kotlin/aws/sdk/kotlin/codegen/ServiceClientCompanionObjectWriter.kt

@@ -82,17 +82,16 @@ internal data class EndpointUrlConfigNames(
 )
 
 internal fun String.toEndpointUrlConfigNames(): EndpointUrlConfigNames = EndpointUrlConfigNames(
-    withTransform(JVMSystemPropertySuffix),
+    withTransform(JvmSystemPropertySuffix),
     withTransform(SdkIdTransform.UpperSnakeCase),
     withTransform(SdkIdTransform.LowerSnakeCase),
 )
 
-// JVM system property names follow those used by the Java SDK, which for service-specific endpoint URL config uses the
-// pattern "aws.endpointUrl${BaseClientName}"
-//
-// this is an arbitrary sdkId transform to replicate the derivation of BaseClientName - see
-// https://github.com/aws/aws-sdk-java-v2/blob/master/codegen/src/main/java/software/amazon/awssdk/codegen/naming/DefaultNamingStrategy.java#L116
-private object JVMSystemPropertySuffix : SdkIdTransformer {
+// JVM system property names follow the pattern "aws.endpointUrl${BaseClientName}"
+// where BaseClientName is the PascalCased sdk ID with any forbidden suffixes dropped - this is the same as what we use
+// for our client names
+// e.g. sdkId "Elasticsearch Service" -> client name "ElasticsearchClient", prop "aws.endpointUrlElasticsearch"
+private object JvmSystemPropertySuffix : SdkIdTransformer {
     override fun transform(id: String): String =
-        id.toPascalCase().removePrefix("Amazon").removePrefix("Aws").removeSuffix("Service")
+        id.toPascalCase().removeSuffix("Service")
 }