Swift 5.9 warning about Hashable being deprecated

[sebsto]

Generate swift code has compilation warning about deprecated protocol.

SamSchema.swift:5645:16: warning: 'Hashable.hashValue' is deprecated as a protocol requirement; conform type 'JSONNull' to 'Hashable' by implementing 'hash(into:)' instead
    public var hashValue: Int {

Using :

swift --version 
swift-driver version: 1.87.1 Apple Swift version 5.9 (swiftlang-5.9.0.128.108 clang-1500.0.40.1)
Target: arm64-apple-macosx14.0

Steps to reproduce :

curl -o sam.schema.json https://raw.githubusercontent.com/aws/serverless-application-model/develop/schema_source/sam.schema.json

quicktype -s schema sam.schema.json -o SamSchema.swift

swift SamSchema.swift 
SamSchema.swift:5645:16: warning: 'Hashable.hashValue' is deprecated as a protocol requirement; conform type 'JSONNull' to 'Hashable' by implementing 'hash(into:)' instead
    public var hashValue: Int {

Expected behaviour : generated code is updated to not include deprecated features.

Thanks !

[schani]

Triage sweep note (systematic issue-backlog triage, assisted by Claude): confirmed reproducible on current master (v23.3.0, 68ecb284), including against the AWS SAM schema from the report.

Root cause: packages/quicktype-core/src/language/Swift/SwiftRenderer.ts:1184 always emits JSONNull's hashValue property, and only emits hash(into:) when the swift5Support option is set (BooleanOption, defaults to false — packages/quicktype-core/src/language/Swift/language.ts:89). Since hashValue alone satisfies Hashable on older Swift but is deprecated in favor of hash(into:) since Swift 4.2, default output triggers the deprecation warning under Swift 5.9. Passing --swift-5-support adds hash(into:) and silences the warning, so a workaround exists today.

Assessment

• Severity: low. Code compiles fine; this is a warning-only cosmetic issue.
• Difficulty: easy. hash(into:) has been available since Swift 4.2, so it can be emitted unconditionally (dropping hashValue, or emitting both) regardless of swift5Support. A few-line renderer change plus updating Swift golden fixtures.

Reproduction (minimal — no need for the full SAM schema; any schema producing a nullable "any" property triggers JSONNull emission):

{
  "$schema": "http://json-schema.org/draft-07/schema#",
  "type": "object",
  "properties": {
    "value": {}
  }
}

$ quicktype -s schema --lang swift schema.json -o Out.swift
$ grep -n "hashValue\|hash(into" Out.swift
68:class JSONNull: Codable, Hashable {
74:    public var hashValue: Int {

No hash(into:) present without --swift-5-support.

Also reproduced directly against the original report's input:

curl -o sam.schema.json https://raw.githubusercontent.com/aws/serverless-application-model/develop/schema_source/sam.schema.json
quicktype -s schema sam.schema.json -o SamSchema.swift
grep -n hashValue SamSchema.swift   # -> public var hashValue: Int {