fix: Add CustomDebugStringConvertible conformance to output-only structs & unions (#1066)

Author: jbelkins

Sources/SmithyCodegenCore/Serialize/SerializeCodegen.swift

@@ -30,11 +30,15 @@ package struct SerializeCodegen {
         writer.write("import typealias SmithySerialization.WriteStructConsumer")
         writer.write("")
 
-        let inputStructsAndUnions = try ctx.service.inputDescendants
+        // Must generate SerializableStruct conformance for all of a service's
+        // structs & unions, not just those that are serialized as part of operation
+        // inputs, so that all structs & unions get the CustomDebugStringConvertible
+        // conformance that hides sensitive data
+        let serviceStructsAndUnions = try ctx.service.descendants
             .filter { $0.type == .structure || $0.type == .union }
             .smithySorted()
 
-        for shape in inputStructsAndUnions {
+        for shape in serviceStructsAndUnions {
             let swiftType = try ctx.symbolProvider.swiftType(shape: shape)
             let varName = shape.type == .structure ? "structure" : "union"
             writer.write("@_spi(SchemaBasedSerde)")

Tests/SmithySerializationTests/StringSerializerTests.swift

@@ -14,6 +14,7 @@ import enum Smithy.Prelude
 import struct Smithy.Schema
 @_spi(SchemaBasedSerde)
 import struct Smithy.SensitiveTrait
+import struct RPCv2CBORTestSDK.GetWidgetOutput
 import enum RPCv2CBORTestSDK.RPCv2CBORServiceClientTypes
 
 final class StringSerializerTests: XCTestCase {
@@ -99,5 +100,11 @@ final class StringSerializerTests: XCTestCase {
             "actual: \(subject.debugDescription)"
         )
     }
+
+    func test_outputFieldsAreRedacted() throws {
+        let sensitiveString = "abcxyz"
+        let subject = GetWidgetOutput(privateString: sensitiveString)
+        XCTAssertFalse(String(reflecting: subject).contains(sensitiveString))
+    }
 }
 

test-sdks/model/model.smithy

@@ -29,6 +29,7 @@ structure GetWidgetInput {
 
 @output
 structure GetWidgetOutput {
+    privateString: PrivateString
 }
 
 structure SensitiveType {