refactor transformers

Author: xinsong-cui

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

@@ -64,15 +64,15 @@ internal data class EndpointUrlConfigNames(
 
 internal fun String.toEndpointUrlConfigNames(): EndpointUrlConfigNames = EndpointUrlConfigNames(
     withTransform(JvmSystemPropertySuffix),
-    withTransform(SdkIdTransform.UpperSnakeCase),
-    withTransform(SdkIdTransform.LowerSnakeCase),
+    withTransform(SdkIdTransformers.UpperSnakeCase),
+    withTransform(SdkIdTransformers.LowerSnakeCase),
 )
 
 // 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 {
+private object JvmSystemPropertySuffix : StringTransformer {
     override fun transform(id: String): String =
         id.toPascalCase().removeSuffix("Service")
 }

codegen/aws-sdk-codegen/src/main/kotlin/aws/sdk/kotlin/codegen/StringTransform.kt

@@ -13,77 +13,39 @@ private val spaceOrDashRegex = Regex("\\s|-")
 /**
  * Base interface for string transformers.
  */
-interface StringTransformer {
+fun interface StringTransformer {
     fun transform(input: String): String
 }
 
-/**
- * Implements a single standardized sdkId transform.
- */
-interface SdkIdTransformer : StringTransformer
-
-/**
- * Implements a single standardized SigV4 service signing name transform.
- */
-interface SigV4NameTransformer : StringTransformer
-
 /**
  * Implements all standardized sdkId transforms.
  */
-object SdkIdTransform {
-    /**
-     * Replace all whitespace from the sdkId with underscores and lowercase all letters.
-     */
-    object LowerSnakeCase : SdkIdTransformer {
-        override fun transform(input: String): String = input.replaceWhitespace("_").lowercase()
-    }
+object SdkIdTransformers {
+    // Replace all whitespace from the sdkId with underscores and lowercase all letters.
+    val LowerSnakeCase = StringTransformer { it.replaceWhitespace("_").lowercase() }
 
-    /**
-     * None. Directly use the sdkId.
-     */
-    object Identity : SdkIdTransformer {
-        override fun transform(input: String): String = input
-    }
+    // None. Directly use the sdkId.
+    val Identity = StringTransformer { it }
 
-    /**
-     * Remove all whitespace from the sdkId.
-     */
-    object NoWhitespace : SdkIdTransformer {
-        override fun transform(input: String): String = input.replaceWhitespace("")
-    }
+    // Remove all whitespace from the sdkId.
+    val NoWhitespace = StringTransformer { it.replaceWhitespace("") }
 
-    /**
-     * Replace all whitespace from the sdkId with dashes and lowercase all letters.
-     */
-    object LowerKebabCase : SdkIdTransformer {
-        override fun transform(input: String): String = input.replaceWhitespace("-").lowercase()
-    }
+    // Replace all whitespace from the sdkId with dashes and lowercase all letters.
+    val LowerKebabCase = StringTransformer { it.replaceWhitespace("-").lowercase() }
 
-    /**
-     * Replace all whitespace from the sdkId with underscores and capitalize all letters.
-     */
-    object UpperSnakeCase : SdkIdTransformer {
-        override fun transform(input: String): String = input.replaceWhitespace("_").uppercase()
-    }
+    // Replace all whitespace from the sdkId with underscores and capitalize all letters.
+    val UpperSnakeCase = StringTransformer { it.replaceWhitespace("_").uppercase() }
 }
 
 /**
  * Implements all standardized SigV4 service signing name transforms.
  */
-object SigV4NameTransform {
-    /**
-     * Replace all dashes from the SigV4 service signing name with underscores and capitalize all letters.
-     */
-    object UpperSnakeCase : SigV4NameTransformer {
-        override fun transform(input: String): String = input.lowercase().replaceSpaceOrDash("_").uppercase()
-    }
+object SigV4NameTransformers {
+    // Replace all dashes from the SigV4 service signing name with underscores and capitalize all letters.
+    val UpperSnakeCase = StringTransformer { it.replaceSpaceOrDash("_").uppercase() }
 
-    /**
-     * Remove dashes and convert SigV4 service signing name to PascalCase
-     */
-    object PascalCase : SigV4NameTransformer {
-        override fun transform(input: String): String = input.toPascalCase()
-    }
+    // Remove dashes and convert SigV4 service signing name to PascalCase
+    val PascalCase = StringTransformer { it.toPascalCase() }
 }
 
 /**

codegen/aws-sdk-codegen/src/main/kotlin/aws/sdk/kotlin/codegen/customization/EnvironmentBearerTokenCustomization.kt

@@ -5,7 +5,7 @@
 package aws.sdk.kotlin.codegen.customization
 
 import aws.sdk.kotlin.codegen.ServiceClientCompanionObjectWriter
-import aws.sdk.kotlin.codegen.SigV4NameTransform
+import aws.sdk.kotlin.codegen.SigV4NameTransformers
 import aws.sdk.kotlin.codegen.withTransform
 import software.amazon.smithy.kotlin.codegen.KotlinSettings
 import software.amazon.smithy.kotlin.codegen.core.*
@@ -69,8 +69,8 @@ class EnvironmentBearerTokenCustomization : KotlinIntegration {
         val serviceSymbol = ctx.symbolProvider.toSymbol(serviceShape)
         val signingServiceName = AwsSignatureVersion4.signingServiceName(serviceShape)
         // Transform signing service name to environment variable key suffix
-        val envSuffix = signingServiceName.withTransform(SigV4NameTransform.UpperSnakeCase)
-        val sysPropSuffix = signingServiceName.withTransform(SigV4NameTransform.PascalCase)
+        val envSuffix = signingServiceName.withTransform(SigV4NameTransformers.UpperSnakeCase)
+        val sysPropSuffix = signingServiceName.withTransform(SigV4NameTransformers.PascalCase)
         val envKey = "AWS_BEARER_TOKEN_$envSuffix"
         val sysPropKey = "aws.bearerToken$sysPropSuffix"
         val authSchemeId = RuntimeTypes.Auth.Identity.AuthSchemeId