feat(codegen): add order parameter to ClientConfigProperty to be used for ordering configuration dependencies (#721)

Author: lauzadis

.changes/490f40f2-97e1-47f9-b53c-d0740e394814.json

@@ -0,0 +1,6 @@
+{
+  "id": "490f40f2-97e1-47f9-b53c-d0740e394814",
+  "type": "feature",
+  "description": "Add order parameter to ClientConfigProperty to be used for ordering configuration dependencies",
+  "issues": ["awslabs/aws-sdk-kotlin/#711"]
+}

smithy-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/rendering/ClientConfigGenerator.kt

@@ -68,7 +68,7 @@ class ClientConfigGenerator(
 
         addPropertyImports()
 
-        props.sortBy { it.propertyName }
+        props.sortWith(compareBy({ it.order }, { it.propertyName }))
         val baseClasses = props
             .mapNotNull { it.baseClass?.name }
             .toSet()

smithy-kotlin-codegen/src/main/kotlin/software/amazon/smithy/kotlin/codegen/rendering/ClientConfigProperty.kt

@@ -69,6 +69,11 @@ class ClientConfigProperty private constructor(builder: Builder) {
      */
     val additionalImports: List<Symbol> = builder.additionalImports
 
+    /**
+     * The priority order of rendering the property. Used to manage dependencies between configuration properties.
+     */
+    val order: Int = builder.order
+
     /**
      * Flag indicating if this property stems from some base class and needs an override modifier when rendered
      */
@@ -144,6 +149,8 @@ class ClientConfigProperty private constructor(builder: Builder) {
 
         var additionalImports: List<Symbol> = emptyList()
 
+        var order: Int = 0
+
         fun build(): ClientConfigProperty = ClientConfigProperty(this)
     }
 }
@@ -237,6 +244,7 @@ object KotlinClientRuntimeConfigProperty {
             NOTE: The caller is responsible for managing the lifetime of the engine when set. The SDK
             client will not close it when the client is closed.
             """.trimIndent()
+            order = -100
         }
 
         IdempotencyTokenProvider = ClientConfigProperty {

smithy-kotlin-codegen/src/test/kotlin/software/amazon/smithy/kotlin/codegen/rendering/ClientConfigGeneratorTest.kt

@@ -40,8 +40,8 @@ public class Config private constructor(builder: Builder): HttpClientConfig, Ide
         contents.shouldContainWithDiff(expectedCtor)
 
         val expectedProps = """
-    public val endpointResolver: EndpointResolver = requireNotNull(builder.endpointResolver) { "endpointResolver is a required configuration property" }
     override val httpClientEngine: HttpClientEngine? = builder.httpClientEngine
+    public val endpointResolver: EndpointResolver = requireNotNull(builder.endpointResolver) { "endpointResolver is a required configuration property" }
     override val idempotencyTokenProvider: IdempotencyTokenProvider? = builder.idempotencyTokenProvider
     public val retryStrategy: RetryStrategy = builder.retryStrategy ?: StandardRetryStrategy()
     override val sdkLogMode: SdkLogMode = builder.sdkLogMode
@@ -50,17 +50,17 @@ public class Config private constructor(builder: Builder): HttpClientConfig, Ide
 
         val expectedBuilder = """
     public class Builder {
-        /**
-         * Set the [aws.smithy.kotlin.runtime.http.endpoints.EndpointResolver] used to resolve service endpoints. Operation requests will be
-         * made against the endpoint returned by the resolver.
-         */
-        public var endpointResolver: EndpointResolver? = null
         /**
          * Override the default HTTP client engine used to make SDK requests (e.g. configure proxy behavior, timeouts, concurrency, etc).
          * NOTE: The caller is responsible for managing the lifetime of the engine when set. The SDK
          * client will not close it when the client is closed.
          */
         public var httpClientEngine: HttpClientEngine? = null
+        /**
+         * Set the [aws.smithy.kotlin.runtime.http.endpoints.EndpointResolver] used to resolve service endpoints. Operation requests will be
+         * made against the endpoint returned by the resolver.
+         */
+        public var endpointResolver: EndpointResolver? = null
         /**
          * Override the default idempotency token generator. SDK clients will generate tokens for members
          * that represent idempotent tokens when not explicitly set by the caller using this generator.