update

Author: thomas-k-cameron

codegen-core/src/main/kotlin/software/amazon/smithy/rust/codegen/core/rustlang/RustWriter.kt

@@ -515,7 +515,6 @@ class RustWriter private constructor(
     init {
         expressionStart = '#'
         if (filename.endsWith(".rs")) {
-            RenderSerdeAttribute.importSerde(this)
             require(namespace.startsWith("crate") || filename.startsWith("tests/")) {
                 "We can only write into files in the crate (got $namespace)"
             }

codegen-core/src/main/kotlin/software/amazon/smithy/rust/codegen/core/smithy/generators/BuilderGenerator.kt

@@ -216,7 +216,7 @@ class BuilderGenerator(
         writer.docs("A builder for #D.", structureSymbol)
         metadata.additionalAttributes.render(writer)
         Attribute(derive(builderDerives)).render(writer)
-        RenderSerdeAttribute.forStructureShape(writer, shape, model)
+        RenderSerdeAttribute.forBuilders(writer, shape, model)
         SensitiveWarning.addDoc(writer, shape)
         writer.rustBlock("pub struct $builderName") {
             // add serde

codegen-core/src/main/kotlin/software/amazon/smithy/rust/codegen/core/smithy/generators/RenderSerdeAttribute.kt

@@ -22,6 +22,12 @@ public object RenderSerdeAttribute {
         }
     }
 
+    public fun forBuilders(writer: RustWriter, shape: StructureShape, model: Model) {
+        if (shape.members().none { it.isEventStream(model) }) {
+            writeAttributes(writer)
+        }
+    }
+
     public fun skipIfStream(writer: RustWriter, member: MemberShape, model: Model) {
         if (member.isEventStream(model)) {
             return
@@ -39,6 +45,8 @@ public object RenderSerdeAttribute {
     }
 
     public fun writeAttributes(writer: RustWriter) {
+        
+
         Attribute("").SerdeSerialize().render(writer)
         Attribute("").SerdeDeserialize().render(writer)
     }

codegen-core/src/main/kotlin/software/amazon/smithy/rust/codegen/core/smithy/generators/StructureGenerator.kt

@@ -160,6 +160,7 @@ open class StructureGenerator(
     }
 
     open fun renderStructure() {
+        RenderSerdeAttribute.importSerde(writer)
         val symbol = symbolProvider.toSymbol(shape)
         val containerMeta = symbol.expectRustMetadata()
         writer.documentShape(shape, model)