From 35ecbb3e02053a65fe87dfccf5c3e280af5dda3a Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Ralph=20K=C3=BCpper?= <ralph@skelpo.com>
Date: Wed, 2 Sep 2026 09:48:27 +0200
Subject: [PATCH 1/3] fix(decorators): instance-member decorators receive
 Class.prototype; C.constructor === Function (#9467)

Two divergences that cancelled, found while fixing #9404 (#9465/#9472):

1. A legacy decorator on an INSTANCE member (property, method, method
   parameter) received the class itself as `target`; tsc's
   `__decorate([...], C.prototype, key, desc)` hands it `Class.prototype`.
   Static members correctly keep the constructor.
2. `C.constructor === C`; node says `Function`. The decl-prototype carries
   `constructor` as an ordinary data field and the constructor-side chain
   walk (`resolve_proto_chain_field`) returned it before the class-ref
   arm's existing `constructor -> Function` tail fallback was reached.

NestJS-style `Reflect.defineMetadata(k, v, target.constructor)` only landed
on `C` because both were wrong. Both halves fixed together:

- perry-hir `lower/decorators.rs`: `member_decorator_target` hands instance
  members `PropertyGet(ClassRef, "prototype")` (the reflective decl-proto
  object), statics `ClassRef`; `design:type` / `design:paramtypes` ride the
  same target. The metadata store's prototype->class fold keeps the
  historical `getMetadata(..., Class, prop)` reads resolving.
- perry-runtime `prototype_objects.rs`: the constructor-side walk also
  skips the `constructor` key, so `C.constructor` falls through to
  `Function`; `C.prototype.constructor` and instance reads are untouched.

Fixture `test_decorators_target_prototype_9467` (expected output from
tsc --experimentalDecorators --emitDecoratorMetadata + reflect-metadata
under node) pins: target identity per member kind, `C.constructor ===
Function`, `p.constructor === C`, and `Reflect.getMetadata` round-trips
through both `target` and `target.constructor`, including inheritance.

Claude-Session: https://claude.ai/code/session_01MmDfS97fv8TRgyDnj6bgsL
---
 CLAUDE.md                                     |   2 +-
 Cargo.lock                                    | 156 +++++++++---------
 Cargo.toml                                    |   2 +-
 crates/perry-hir/src/lower/decorators.rs      |  80 ++++++---
 .../class_registry/prototype_objects.rs       |  40 +++--
 docs/src/language/decorators.md               |   6 +-
 .../test_decorators_target_prototype_9467.ts  | 108 ++++++++++++
 .../test_decorators_target_prototype_9467.txt |  30 ++++
 8 files changed, 306 insertions(+), 118 deletions(-)
 create mode 100644 test-files/test_decorators_target_prototype_9467.ts
 create mode 100644 test-parity/expected/test_decorators_target_prototype_9467.txt

diff --git a/CLAUDE.md b/CLAUDE.md
index 61bf8dcebb..94d8b53bf4 100644
--- a/CLAUDE.md
+++ b/CLAUDE.md
@@ -8,7 +8,7 @@ This file provides guidance to Claude Code (claude.ai/code) when working with co
 
 Perry is a native TypeScript compiler written in Rust that compiles TypeScript source code directly to native executables. It uses SWC for TypeScript parsing and LLVM for code generation.
 
-**Current Version:** 0.5.1519
+**Current Version:** 0.5.1520
 
 
 ## TypeScript Parity Status
diff --git a/Cargo.lock b/Cargo.lock
index e9077d6199..d6c4beedb8 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -5632,7 +5632,7 @@ checksum = "9b4f627cb1b25917193a259e49bdad08f671f8d9708acfd5fe0a8c1455d87220"
 
 [[package]]
 name = "perry"
-version = "0.5.1519"
+version = "0.5.1520"
 dependencies = [
  "anyhow",
  "base64 0.22.1",
@@ -5694,7 +5694,7 @@ dependencies = [
 
 [[package]]
 name = "perry-api-manifest"
-version = "0.5.1519"
+version = "0.5.1520"
 dependencies = [
  "perry-dispatch",
  "serde",
@@ -5702,7 +5702,7 @@ dependencies = [
 
 [[package]]
 name = "perry-audio-miniaudio"
-version = "0.5.1519"
+version = "0.5.1520"
 dependencies = [
  "cc",
  "libc",
@@ -5711,7 +5711,7 @@ dependencies = [
 
 [[package]]
 name = "perry-codegen"
-version = "0.5.1519"
+version = "0.5.1520"
 dependencies = [
  "anyhow",
  "inkwell",
@@ -5728,7 +5728,7 @@ dependencies = [
 
 [[package]]
 name = "perry-codegen-arkts"
-version = "0.5.1519"
+version = "0.5.1520"
 dependencies = [
  "anyhow",
  "perry-hir",
@@ -5736,7 +5736,7 @@ dependencies = [
 
 [[package]]
 name = "perry-codegen-glance"
-version = "0.5.1519"
+version = "0.5.1520"
 dependencies = [
  "anyhow",
  "perry-hir",
@@ -5744,7 +5744,7 @@ dependencies = [
 
 [[package]]
 name = "perry-codegen-js"
-version = "0.5.1519"
+version = "0.5.1520"
 dependencies = [
  "anyhow",
  "perry-dispatch",
@@ -5753,7 +5753,7 @@ dependencies = [
 
 [[package]]
 name = "perry-codegen-swiftui"
-version = "0.5.1519"
+version = "0.5.1520"
 dependencies = [
  "anyhow",
  "perry-hir",
@@ -5761,7 +5761,7 @@ dependencies = [
 
 [[package]]
 name = "perry-codegen-wasm"
-version = "0.5.1519"
+version = "0.5.1520"
 dependencies = [
  "anyhow",
  "base64 0.22.1",
@@ -5773,7 +5773,7 @@ dependencies = [
 
 [[package]]
 name = "perry-codegen-wear-tiles"
-version = "0.5.1519"
+version = "0.5.1520"
 dependencies = [
  "anyhow",
  "perry-hir",
@@ -5781,7 +5781,7 @@ dependencies = [
 
 [[package]]
 name = "perry-container-compose"
-version = "0.5.1519"
+version = "0.5.1520"
 dependencies = [
  "anyhow",
  "async-trait",
@@ -5810,14 +5810,14 @@ dependencies = [
 
 [[package]]
 name = "perry-container-e2e"
-version = "0.5.1519"
+version = "0.5.1520"
 dependencies = [
  "anyhow",
 ]
 
 [[package]]
 name = "perry-diagnostics"
-version = "0.5.1519"
+version = "0.5.1520"
 dependencies = [
  "serde",
  "serde_json",
@@ -5825,7 +5825,7 @@ dependencies = [
 
 [[package]]
 name = "perry-dispatch"
-version = "0.5.1519"
+version = "0.5.1520"
 
 [[package]]
 name = "perry-doc-fixture-my-bindings"
@@ -5836,7 +5836,7 @@ dependencies = [
 
 [[package]]
 name = "perry-doc-tests"
-version = "0.5.1519"
+version = "0.5.1520"
 dependencies = [
  "anyhow",
  "clap",
@@ -5851,7 +5851,7 @@ dependencies = [
 
 [[package]]
 name = "perry-ext-ads"
-version = "0.5.1519"
+version = "0.5.1520"
 dependencies = [
  "block2",
  "objc2",
@@ -5861,7 +5861,7 @@ dependencies = [
 
 [[package]]
 name = "perry-ext-argon2"
-version = "0.5.1519"
+version = "0.5.1520"
 dependencies = [
  "argon2",
  "perry-ffi",
@@ -5870,7 +5870,7 @@ dependencies = [
 
 [[package]]
 name = "perry-ext-axios"
-version = "0.5.1519"
+version = "0.5.1520"
 dependencies = [
  "perry-ffi",
  "reqwest",
@@ -5879,7 +5879,7 @@ dependencies = [
 
 [[package]]
 name = "perry-ext-bcrypt"
-version = "0.5.1519"
+version = "0.5.1520"
 dependencies = [
  "bcrypt",
  "perry-ffi",
@@ -5887,7 +5887,7 @@ dependencies = [
 
 [[package]]
 name = "perry-ext-better-sqlite3"
-version = "0.5.1519"
+version = "0.5.1520"
 dependencies = [
  "perry-ffi",
  "rusqlite",
@@ -5895,7 +5895,7 @@ dependencies = [
 
 [[package]]
 name = "perry-ext-cheerio"
-version = "0.5.1519"
+version = "0.5.1520"
 dependencies = [
  "perry-ffi",
  "scraper",
@@ -5903,7 +5903,7 @@ dependencies = [
 
 [[package]]
 name = "perry-ext-commander"
-version = "0.5.1519"
+version = "0.5.1520"
 dependencies = [
  "perry-ffi",
  "perry-runtime",
@@ -5911,7 +5911,7 @@ dependencies = [
 
 [[package]]
 name = "perry-ext-cron"
-version = "0.5.1519"
+version = "0.5.1520"
 dependencies = [
  "chrono",
  "cron",
@@ -5921,7 +5921,7 @@ dependencies = [
 
 [[package]]
 name = "perry-ext-dayjs"
-version = "0.5.1519"
+version = "0.5.1520"
 dependencies = [
  "chrono",
  "perry-ffi",
@@ -5929,7 +5929,7 @@ dependencies = [
 
 [[package]]
 name = "perry-ext-decimal"
-version = "0.5.1519"
+version = "0.5.1520"
 dependencies = [
  "perry-ffi",
  "rust_decimal",
@@ -5937,7 +5937,7 @@ dependencies = [
 
 [[package]]
 name = "perry-ext-dotenv"
-version = "0.5.1519"
+version = "0.5.1520"
 dependencies = [
  "perry-ffi",
  "serde_json",
@@ -5945,7 +5945,7 @@ dependencies = [
 
 [[package]]
 name = "perry-ext-ethers"
-version = "0.5.1519"
+version = "0.5.1520"
 dependencies = [
  "perry-ffi",
  "rand 0.10.2",
@@ -5953,7 +5953,7 @@ dependencies = [
 
 [[package]]
 name = "perry-ext-events"
-version = "0.5.1519"
+version = "0.5.1520"
 dependencies = [
  "perry-ffi",
  "perry-runtime",
@@ -5961,14 +5961,14 @@ dependencies = [
 
 [[package]]
 name = "perry-ext-exponential-backoff"
-version = "0.5.1519"
+version = "0.5.1520"
 dependencies = [
  "perry-ffi",
 ]
 
 [[package]]
 name = "perry-ext-fastify"
-version = "0.5.1519"
+version = "0.5.1520"
 dependencies = [
  "bytes",
  "http-body-util",
@@ -5986,7 +5986,7 @@ dependencies = [
 
 [[package]]
 name = "perry-ext-fetch"
-version = "0.5.1519"
+version = "0.5.1520"
 dependencies = [
  "bytes",
  "lazy_static",
@@ -5999,7 +5999,7 @@ dependencies = [
 
 [[package]]
 name = "perry-ext-http"
-version = "0.5.1519"
+version = "0.5.1520"
 dependencies = [
  "base64 0.22.1",
  "bytes",
@@ -6031,7 +6031,7 @@ dependencies = [
 
 [[package]]
 name = "perry-ext-ioredis"
-version = "0.5.1519"
+version = "0.5.1520"
 dependencies = [
  "lazy_static",
  "perry-ffi",
@@ -6041,7 +6041,7 @@ dependencies = [
 
 [[package]]
 name = "perry-ext-jsonwebtoken"
-version = "0.5.1519"
+version = "0.5.1520"
 dependencies = [
  "base64 0.22.1",
  "jsonwebtoken",
@@ -6052,7 +6052,7 @@ dependencies = [
 
 [[package]]
 name = "perry-ext-lru-cache"
-version = "0.5.1519"
+version = "0.5.1520"
 dependencies = [
  "lru",
  "perry-ffi",
@@ -6061,7 +6061,7 @@ dependencies = [
 
 [[package]]
 name = "perry-ext-moment"
-version = "0.5.1519"
+version = "0.5.1520"
 dependencies = [
  "chrono",
  "perry-ffi",
@@ -6069,7 +6069,7 @@ dependencies = [
 
 [[package]]
 name = "perry-ext-mongodb"
-version = "0.5.1519"
+version = "0.5.1520"
 dependencies = [
  "bson",
  "futures-util",
@@ -6081,7 +6081,7 @@ dependencies = [
 
 [[package]]
 name = "perry-ext-mysql2"
-version = "0.5.1519"
+version = "0.5.1520"
 dependencies = [
  "chrono",
  "perry-ffi",
@@ -6093,7 +6093,7 @@ dependencies = [
 
 [[package]]
 name = "perry-ext-nanoid"
-version = "0.5.1519"
+version = "0.5.1520"
 dependencies = [
  "nanoid",
  "perry-ffi",
@@ -6102,7 +6102,7 @@ dependencies = [
 
 [[package]]
 name = "perry-ext-net"
-version = "0.5.1519"
+version = "0.5.1520"
 dependencies = [
  "bytes",
  "perry-ffi",
@@ -6117,7 +6117,7 @@ dependencies = [
 
 [[package]]
 name = "perry-ext-node-forge"
-version = "0.5.1519"
+version = "0.5.1520"
 dependencies = [
  "const-oid 0.10.2",
  "der 0.8.1",
@@ -6136,7 +6136,7 @@ dependencies = [
 
 [[package]]
 name = "perry-ext-nodemailer"
-version = "0.5.1519"
+version = "0.5.1520"
 dependencies = [
  "lettre",
  "perry-ffi",
@@ -6146,7 +6146,7 @@ dependencies = [
 
 [[package]]
 name = "perry-ext-parcel-watcher"
-version = "0.5.1519"
+version = "0.5.1520"
 dependencies = [
  "fancy-regex",
  "notify",
@@ -6158,7 +6158,7 @@ dependencies = [
 
 [[package]]
 name = "perry-ext-pdf"
-version = "0.5.1519"
+version = "0.5.1520"
 dependencies = [
  "perry-ffi",
  "printpdf",
@@ -6166,7 +6166,7 @@ dependencies = [
 
 [[package]]
 name = "perry-ext-pg"
-version = "0.5.1519"
+version = "0.5.1520"
 dependencies = [
  "perry-ffi",
  "sqlx",
@@ -6175,7 +6175,7 @@ dependencies = [
 
 [[package]]
 name = "perry-ext-qs"
-version = "0.5.1519"
+version = "0.5.1520"
 dependencies = [
  "perry-ffi",
  "perry-runtime",
@@ -6184,7 +6184,7 @@ dependencies = [
 
 [[package]]
 name = "perry-ext-ratelimit"
-version = "0.5.1519"
+version = "0.5.1520"
 dependencies = [
  "governor",
  "perry-ffi",
@@ -6192,7 +6192,7 @@ dependencies = [
 
 [[package]]
 name = "perry-ext-sharp"
-version = "0.5.1519"
+version = "0.5.1520"
 dependencies = [
  "fast_image_resize",
  "image",
@@ -6203,7 +6203,7 @@ dependencies = [
 
 [[package]]
 name = "perry-ext-streams"
-version = "0.5.1519"
+version = "0.5.1520"
 dependencies = [
  "lazy_static",
  "perry-ffi",
@@ -6212,7 +6212,7 @@ dependencies = [
 
 [[package]]
 name = "perry-ext-typescript"
-version = "0.5.1519"
+version = "0.5.1520"
 dependencies = [
  "perry-ffi",
  "serde",
@@ -6228,7 +6228,7 @@ dependencies = [
 
 [[package]]
 name = "perry-ext-undici"
-version = "0.5.1519"
+version = "0.5.1520"
 dependencies = [
  "perry-ffi",
  "perry-runtime",
@@ -6237,7 +6237,7 @@ dependencies = [
 
 [[package]]
 name = "perry-ext-uuid"
-version = "0.5.1519"
+version = "0.5.1520"
 dependencies = [
  "perry-ffi",
  "uuid",
@@ -6245,7 +6245,7 @@ dependencies = [
 
 [[package]]
 name = "perry-ext-validator"
-version = "0.5.1519"
+version = "0.5.1520"
 dependencies = [
  "perry-ffi",
  "regex",
@@ -6255,7 +6255,7 @@ dependencies = [
 
 [[package]]
 name = "perry-ext-ws"
-version = "0.5.1519"
+version = "0.5.1520"
 dependencies = [
  "futures-util",
  "lazy_static",
@@ -6268,7 +6268,7 @@ dependencies = [
 
 [[package]]
 name = "perry-ext-zlib"
-version = "0.5.1519"
+version = "0.5.1520"
 dependencies = [
  "brotli",
  "flate2",
@@ -6278,7 +6278,7 @@ dependencies = [
 
 [[package]]
 name = "perry-ffi"
-version = "0.5.1519"
+version = "0.5.1520"
 dependencies = [
  "dashmap",
  "once_cell",
@@ -6287,7 +6287,7 @@ dependencies = [
 
 [[package]]
 name = "perry-hir"
-version = "0.5.1519"
+version = "0.5.1520"
 dependencies = [
  "anyhow",
  "perry-api-manifest",
@@ -6306,7 +6306,7 @@ dependencies = [
 
 [[package]]
 name = "perry-parser"
-version = "0.5.1519"
+version = "0.5.1520"
 dependencies = [
  "anyhow",
  "perry-diagnostics",
@@ -6319,7 +6319,7 @@ dependencies = [
 
 [[package]]
 name = "perry-runtime"
-version = "0.5.1519"
+version = "0.5.1520"
 dependencies = [
  "anyhow",
  "base64 0.22.1",
@@ -6369,14 +6369,14 @@ dependencies = [
 
 [[package]]
 name = "perry-runtime-static"
-version = "0.5.1519"
+version = "0.5.1520"
 dependencies = [
  "perry-runtime",
 ]
 
 [[package]]
 name = "perry-stdlib"
-version = "0.5.1519"
+version = "0.5.1520"
 dependencies = [
  "aes 0.8.4",
  "aes 0.9.1",
@@ -6471,14 +6471,14 @@ dependencies = [
 
 [[package]]
 name = "perry-stdlib-static"
-version = "0.5.1519"
+version = "0.5.1520"
 dependencies = [
  "perry-stdlib",
 ]
 
 [[package]]
 name = "perry-transform"
-version = "0.5.1519"
+version = "0.5.1520"
 dependencies = [
  "anyhow",
  "perry-hir",
@@ -6487,7 +6487,7 @@ dependencies = [
 
 [[package]]
 name = "perry-ui"
-version = "0.5.1519"
+version = "0.5.1520"
 dependencies = [
  "perry-ffi",
  "perry-ui-model",
@@ -6495,7 +6495,7 @@ dependencies = [
 
 [[package]]
 name = "perry-ui-android"
-version = "0.5.1519"
+version = "0.5.1520"
 dependencies = [
  "base64 0.22.1",
  "itoa",
@@ -6513,7 +6513,7 @@ dependencies = [
 
 [[package]]
 name = "perry-ui-geisterhand"
-version = "0.5.1519"
+version = "0.5.1520"
 dependencies = [
  "rand 0.10.2",
  "serde",
@@ -6523,7 +6523,7 @@ dependencies = [
 
 [[package]]
 name = "perry-ui-gtk4"
-version = "0.5.1519"
+version = "0.5.1520"
 dependencies = [
  "base64 0.22.1",
  "cairo-rs 0.22.0",
@@ -6546,7 +6546,7 @@ dependencies = [
 
 [[package]]
 name = "perry-ui-ios"
-version = "0.5.1519"
+version = "0.5.1520"
 dependencies = [
  "base64 0.22.1",
  "block2",
@@ -6563,7 +6563,7 @@ dependencies = [
 
 [[package]]
 name = "perry-ui-macos"
-version = "0.5.1519"
+version = "0.5.1520"
 dependencies = [
  "base64 0.22.1",
  "block2",
@@ -6579,7 +6579,7 @@ dependencies = [
 
 [[package]]
 name = "perry-ui-model"
-version = "0.5.1519"
+version = "0.5.1520"
 
 [[package]]
 name = "perry-ui-test"
@@ -6590,11 +6590,11 @@ dependencies = [
 
 [[package]]
 name = "perry-ui-testkit"
-version = "0.5.1519"
+version = "0.5.1520"
 
 [[package]]
 name = "perry-ui-tvos"
-version = "0.5.1519"
+version = "0.5.1520"
 dependencies = [
  "base64 0.22.1",
  "block2",
@@ -6611,7 +6611,7 @@ dependencies = [
 
 [[package]]
 name = "perry-ui-visionos"
-version = "0.5.1519"
+version = "0.5.1520"
 dependencies = [
  "base64 0.22.1",
  "block2",
@@ -6628,7 +6628,7 @@ dependencies = [
 
 [[package]]
 name = "perry-ui-watchos"
-version = "0.5.1519"
+version = "0.5.1520"
 dependencies = [
  "block2",
  "libc",
@@ -6642,7 +6642,7 @@ dependencies = [
 
 [[package]]
 name = "perry-ui-windows"
-version = "0.5.1519"
+version = "0.5.1520"
 dependencies = [
  "base64 0.22.1",
  "libc",
@@ -6661,7 +6661,7 @@ dependencies = [
 
 [[package]]
 name = "perry-ui-windows-winui"
-version = "0.5.1519"
+version = "0.5.1520"
 dependencies = [
  "base64 0.22.1",
  "libc",
@@ -6674,7 +6674,7 @@ dependencies = [
 
 [[package]]
 name = "perry-updater"
-version = "0.5.1519"
+version = "0.5.1520"
 dependencies = [
  "anyhow",
  "base64 0.22.1",
@@ -6690,7 +6690,7 @@ dependencies = [
 
 [[package]]
 name = "perry-wasm-host"
-version = "0.5.1519"
+version = "0.5.1520"
 dependencies = [
  "wasmi",
 ]
diff --git a/Cargo.toml b/Cargo.toml
index 08061d929f..7652038146 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -335,7 +335,7 @@ codegen-units = 16
 codegen-units = 16
 
 [workspace.package]
-version = "0.5.1519"
+version = "0.5.1520"
 edition = "2021"
 license = "MIT"
 repository = "https://github.com/PerryTS/perry"
diff --git a/crates/perry-hir/src/lower/decorators.rs b/crates/perry-hir/src/lower/decorators.rs
index 37dc8532da..ed41b54d25 100644
--- a/crates/perry-hir/src/lower/decorators.rs
+++ b/crates/perry-hir/src/lower/decorators.rs
@@ -64,16 +64,16 @@ pub(crate) fn append_legacy_decorator_init_for_class(
     }
 
     for method in &class.methods {
-        append_method_decorator_init(ctx, init, class, method);
+        append_method_decorator_init(ctx, init, class, method, false);
     }
     for method in &class.static_methods {
-        append_method_decorator_init(ctx, init, class, method);
+        append_method_decorator_init(ctx, init, class, method, true);
     }
     for field in &class.fields {
-        append_property_decorator_init(ctx, init, class, field);
+        append_property_decorator_init(ctx, init, class, field, false);
     }
     for field in &class.static_fields {
-        append_property_decorator_init(ctx, init, class, field);
+        append_property_decorator_init(ctx, init, class, field, true);
     }
 
     append_class_decorator_invocations(
@@ -93,29 +93,60 @@ fn field_has_legacy_decorators(field: &ClassField) -> bool {
     !field.decorators.is_empty()
 }
 
+/// The `target` a legacy member decorator receives (#9467).
+///
+/// `tsc` emits `__decorate([...], C.prototype, "m", desc)` for an INSTANCE
+/// member and `__decorate([...], C, "s", desc)` for a STATIC one, and the
+/// `design:*` metadata rides the same target. Perry used to hand every member
+/// decorator the class itself; NestJS-style code
+/// (`Reflect.defineMetadata(k, v, target.constructor)`) only kept working
+/// because the runtime answered `C.constructor === C` — a second divergence
+/// that cancelled the first (node: `C.constructor === Function`). Both were
+/// fixed together; the runtime half is the `constructor` clause of
+/// `resolve_proto_chain_field_inner` in
+/// `perry-runtime/src/object/class_registry/prototype_objects.rs`.
+///
+/// `Class.prototype` is read as an ordinary `PropertyGet` on the class ref,
+/// which the class-ref arm of `js_object_get_field_by_name` materializes as
+/// the reflective decl-prototype object (`class_decl_prototype_value`) — the
+/// same object `C.prototype` answers with everywhere else, so
+/// `target === C.prototype` and `target.constructor === C` both hold.
+fn member_decorator_target(class: &Class, is_static: bool) -> Expr {
+    if is_static {
+        Expr::ClassRef(class.name.clone())
+    } else {
+        Expr::PropertyGet {
+            object: Box::new(Expr::ClassRef(class.name.clone())),
+            property: "prototype".to_string(),
+            byte_offset: 0,
+        }
+    }
+}
+
 fn append_property_decorator_init(
     ctx: &mut LoweringContext,
     out: &mut Vec<Stmt>,
     class: &Class,
     field: &ClassField,
+    is_static: bool,
 ) {
     if field.decorators.is_empty() {
         return;
     }
 
-    // NOTE: TypeScript's `emitDecoratorMetadata` stores instance-member
-    // `design:type` on `Class.prototype`, and class-transformer reads it back
-    // with `Reflect.getMetadata("design:type", SomeClass.prototype, prop)`.
-    // Perry stores it on the class constructor (`ClassRef`) here; the runtime
-    // metadata store folds class-prototype lookup targets onto the same class
-    // key (see `proxy/metadata.rs::normalize_target_bits`), so both the
-    // historical `getMetadata(..., Class, prop)` reads (locked in by
-    // test_decorators_legacy_property_metadata.ts) and the library's
-    // `Class.prototype` reads resolve to this entry.
+    // `design:type` rides the decorator's own target — `Class.prototype` for
+    // an instance member, the constructor for a static one (#9467) — which is
+    // where class-transformer reads it back
+    // (`Reflect.getMetadata("design:type", SomeClass.prototype, prop)`). The
+    // runtime metadata store folds prototype targets onto the class key (see
+    // `proxy/metadata.rs::normalize_target_bits`), so the historical
+    // `getMetadata(..., Class, prop)` reads locked in by
+    // test_decorators_legacy_property_metadata.ts keep resolving too.
+    let target = member_decorator_target(class, is_static);
     out.push(Stmt::Expr(Expr::ReflectDefineMetadata {
         key: Box::new(Expr::String("design:type".to_string())),
         value: Box::new(type_metadata_expr(&field.ty)),
-        target: Box::new(Expr::ClassRef(class.name.clone())),
+        target: Box::new(target.clone()),
         property_key: Some(Box::new(Expr::String(field.name.clone()))),
     }));
 
@@ -123,10 +154,7 @@ fn append_property_decorator_init(
         ctx,
         out,
         &field.decorators,
-        vec![
-            Expr::ClassRef(class.name.clone()),
-            Expr::String(field.name.clone()),
-        ],
+        vec![target, Expr::String(field.name.clone())],
     );
 }
 
@@ -135,11 +163,17 @@ fn append_method_decorator_init(
     out: &mut Vec<Stmt>,
     class: &Class,
     method: &Function,
+    is_static: bool,
 ) {
     if !method_has_legacy_decorators(method) {
         return;
     }
 
+    // #9467: `Class.prototype` for an instance method, the constructor for a
+    // static one — the target of the method decorator, its parameter
+    // decorators, and their `design:paramtypes` alike (one `__decorate` call
+    // in `tsc`'s emit carries all three).
+    let target = member_decorator_target(class, is_static);
     if method.params.iter().any(|p| !p.decorators.is_empty()) || !method.decorators.is_empty() {
         let param_types = method
             .params
@@ -149,7 +183,7 @@ fn append_method_decorator_init(
         out.push(Stmt::Expr(Expr::ReflectDefineMetadata {
             key: Box::new(Expr::String("design:paramtypes".to_string())),
             value: Box::new(Expr::Array(param_types)),
-            target: Box::new(Expr::ClassRef(class.name.clone())),
+            target: Box::new(target.clone()),
             property_key: Some(Box::new(Expr::String(method.name.clone()))),
         }));
     }
@@ -160,7 +194,7 @@ fn append_method_decorator_init(
             out,
             &param.decorators,
             vec![
-                Expr::ClassRef(class.name.clone()),
+                target.clone(),
                 Expr::String(method.name.clone()),
                 Expr::Number(index as f64),
             ],
@@ -187,11 +221,7 @@ fn append_method_decorator_init(
         ctx,
         out,
         &method.decorators,
-        vec![
-            Expr::ClassRef(class.name.clone()),
-            Expr::String(method.name.clone()),
-            descriptor,
-        ],
+        vec![target, Expr::String(method.name.clone()), descriptor],
     );
 }
 
diff --git a/crates/perry-runtime/src/object/class_registry/prototype_objects.rs b/crates/perry-runtime/src/object/class_registry/prototype_objects.rs
index 1271493e24..ec638bb7dd 100644
--- a/crates/perry-runtime/src/object/class_registry/prototype_objects.rs
+++ b/crates/perry-runtime/src/object/class_registry/prototype_objects.rs
@@ -403,18 +403,30 @@ unsafe fn inherited_proto_accessor_value(
 /// door for #1021/NestJS; this is that door's chain-walk twin.
 ///
 /// The exclusion is keyed on `class_instance_has_member` — the exact
-/// "is this a prototype method / getter / setter of the chain" predicate — and
-/// NOT on "skip the decl-prototype entirely". A blanket skip also removed
-/// `C.constructor`, which the decl-prototype carries as an ordinary data field,
-/// and that is load-bearing today for a reason outside this issue: perry hands
-/// a PROPERTY DECORATOR the class itself where the spec hands it
-/// `Class.prototype`, so NestJS-style `Reflect.defineMetadata(k, v,
-/// target.constructor)` relies on `C.constructor === C`. Node says
-/// `C.constructor === Function`, so perry has two divergences that cancel;
-/// removing either one alone breaks decorator metadata
+/// "is this a prototype method / getter / setter of the chain" predicate —
+/// plus the `constructor` back-edge, and NOT on "skip the decl-prototype
+/// entirely": a blanket skip would also hide a user's own
+/// `Object.defineProperty(C.prototype, ...)` data field from this walk.
+///
+/// #9467: `constructor` is the one decl-prototype data field that is NOT an
+/// instance member by `class_instance_has_member`'s definition, and walking
+/// into it from the constructor side answered `C.constructor === C`. Node says
+/// `C.constructor === Function` — a constructor object's own chain is
+/// `C → Function.prototype`, with no back-edge to `C`; only
+/// `C.prototype.constructor` and `(new C()).constructor` are `C`. The
+/// `Function` answer already existed as the tail fallback of the class-ref arm
+/// in `get_field_by_name.rs`; this walk simply returned first. The wrong
+/// answer used to be load-bearing: perry handed a decorator on an INSTANCE
+/// member the class itself where the spec hands it `Class.prototype`, so
+/// NestJS-style `Reflect.defineMetadata(k, v, target.constructor)` landed on
+/// `C` only because `C.constructor === C`. Two divergences that cancelled;
+/// fixing either alone broke decorator metadata
 /// (`test_decorators_nest_common_canary`,
-/// `test_decorators_legacy_property_metadata`). The decorator-target defect is
-/// the one to fix, and it is not this issue.
+/// `test_decorators_legacy_property_metadata`). Both halves were fixed
+/// together — the decorator target in
+/// `perry-hir/src/lower/decorators.rs::member_decorator_target` and the
+/// `constructor` clause below; `test_decorators_target_prototype_9467` pins
+/// the pair.
 ///
 /// The `class_prototype_object` step below is never skipped: for a subclass of
 /// a class-EXPRESSION value it holds the parent CLASS OBJECT (#1788/#6552),
@@ -432,7 +444,11 @@ unsafe fn resolve_proto_chain_field_inner(
         let key_ptr = crate::string::string_data(key);
         let key_len = (*key).byte_len as usize;
         std::str::from_utf8(std::slice::from_raw_parts(key_ptr, key_len))
-            .map(|name| crate::object::class_instance_has_member(class_id, name))
+            .map(|name| {
+                // #9467: `C.prototype.constructor` is `C`; `C.constructor` is
+                // `Function` (the class-ref arm's tail fallback), never `C`.
+                name == "constructor" || crate::object::class_instance_has_member(class_id, name)
+            })
             .unwrap_or(false)
     };
     let mut cid = class_id;
diff --git a/docs/src/language/decorators.md b/docs/src/language/decorators.md
index 8034111784..32c8293f95 100644
--- a/docs/src/language/decorators.md
+++ b/docs/src/language/decorators.md
@@ -36,7 +36,11 @@ supports two paths:
   `Reflect.getOwnMetadataKeys`, `Reflect.deleteMetadata`, and
   `@Reflect.metadata(...)` are available. Perry emits
   `design:paramtypes` for decorated classes/methods and `design:type`
-  for decorated properties.
+  for decorated properties. A member decorator receives the same
+  `target` `tsc` hands it: `Class.prototype` for an instance member and
+  the constructor for a static one, so the NestJS idiom
+  `Reflect.defineMetadata(key, value, target.constructor)` lands on the
+  class, and `Class.constructor === Function` as in node.
 - **Compile-time-only transforms.** The bundled `@log` transform is the
   canonical example — it rewrites a decorated method into a wrapper that
   prints entry/exit at compile time, with zero runtime decorator
diff --git a/test-files/test_decorators_target_prototype_9467.ts b/test-files/test_decorators_target_prototype_9467.ts
new file mode 100644
index 0000000000..f679f838fd
--- /dev/null
+++ b/test-files/test_decorators_target_prototype_9467.ts
@@ -0,0 +1,108 @@
+// #9467: a legacy decorator on an INSTANCE member receives `Class.prototype`
+// as its `target` — what tsc's `__decorate([...], C.prototype, key, desc)`
+// hands it — and a decorator on a STATIC member receives the constructor.
+// Separately, a class constructor's own `constructor` is inherited from
+// Function.prototype: `C.constructor === Function`, never `C`; only
+// `C.prototype.constructor` and `(new C()).constructor` are `C`.
+//
+// Perry used to get both wrong in a way that cancelled (target = C and
+// C.constructor = C), so the NestJS idiom
+// `Reflect.defineMetadata(k, v, target.constructor)` landed on C by accident.
+// Fixing either half alone broke decorator metadata; this fixture pins the
+// pair. Decorator application ORDER across member kinds is deliberately not
+// under test (records are collected, then printed sorted).
+import "reflect-metadata";
+
+class Repo {}
+
+const seen = new Map<string, string>();
+
+function describeTarget(target: any): string {
+  if (target === Service) return "Service";
+  if (target === Service.prototype) return "Service.prototype";
+  return "other:" + typeof target;
+}
+
+function Prop(): PropertyDecorator {
+  return (target: any, key: string | symbol) => {
+    seen.set(
+      "prop:" + String(key),
+      describeTarget(target) + " ctor===Service:" + (target.constructor === Service),
+    );
+    Reflect.defineMetadata("via:target", "T:" + String(key), target, key);
+    Reflect.defineMetadata("via:ctor", "C:" + String(key), target.constructor, key);
+  };
+}
+
+function Method(): MethodDecorator {
+  return (target: any, key: string | symbol, desc: PropertyDescriptor) => {
+    seen.set(
+      "method:" + String(key),
+      describeTarget(target) +
+        " ctor===Service:" +
+        (target.constructor === Service) +
+        " value:" +
+        typeof desc.value,
+    );
+    Reflect.defineMetadata("via:ctor", "M:" + String(key), target.constructor, key);
+  };
+}
+
+function Param(): ParameterDecorator {
+  return (target: any, key: string | symbol | undefined, index: number) => {
+    seen.set(
+      "param:" + String(key) + ":" + index,
+      describeTarget(target) + " ctor===Service:" + (target.constructor === Service),
+    );
+    if (key !== undefined) {
+      Reflect.defineMetadata("param:via:ctor", index, target.constructor, key);
+    }
+  };
+}
+
+class Service {
+  @Prop()
+  repo!: Repo;
+
+  @Prop()
+  static counter: number = 0;
+
+  @Method()
+  run(@Param() a: Repo) {}
+
+  @Method()
+  static make(@Param() n: number) {}
+
+  constructor(@Param() r: Repo) {}
+}
+
+class Sub extends Service {}
+
+for (const k of [...seen.keys()].sort()) {
+  console.log(k, "->", seen.get(k));
+}
+
+console.log("Service.constructor === Function", Service.constructor === Function);
+console.log("Service.constructor === Service", Service.constructor === Service);
+console.log("Sub.constructor === Function", Sub.constructor === Function);
+console.log("typeof Service.constructor", typeof Service.constructor);
+console.log("Service.constructor.name", Service.constructor.name);
+console.log("Service.prototype.constructor === Service", Service.prototype.constructor === Service);
+console.log("Sub.prototype.constructor === Sub", Sub.prototype.constructor === Sub);
+console.log("instance.constructor === Service", new Service(new Repo()).constructor === Service);
+console.log("sub instance.constructor === Sub", new Sub(new Repo()).constructor === Sub);
+console.log("'constructor' in Service", "constructor" in Service);
+console.log("hasOwn constructor", Object.prototype.hasOwnProperty.call(Service, "constructor"));
+
+console.log("design:type via prototype", Reflect.getMetadata("design:type", Service.prototype, "repo") === Repo);
+console.log("design:type static via class", Reflect.getMetadata("design:type", Service, "counter") === Number);
+console.log("design:paramtypes ctor", Reflect.getMetadata("design:paramtypes", Service)[0] === Repo);
+console.log("design:paramtypes method via prototype", Reflect.getMetadata("design:paramtypes", Service.prototype, "run")[0] === Repo);
+console.log("design:paramtypes static via class", Reflect.getMetadata("design:paramtypes", Service, "make")[0] === Number);
+console.log("via:target on prototype", Reflect.getMetadata("via:target", Service.prototype, "repo"));
+console.log("via:ctor on class", Reflect.getMetadata("via:ctor", Service, "repo"));
+console.log("via:ctor method on class", Reflect.getMetadata("via:ctor", Service, "run"));
+console.log("param:via:ctor on class", Reflect.getMetadata("param:via:ctor", Service, "run"));
+console.log("via:ctor inherited on Sub", Reflect.getMetadata("via:ctor", Sub, "repo"));
+console.log("via:target inherited on Sub.prototype", Reflect.getMetadata("via:target", Sub.prototype, "repo"));
+console.log("nothing for repo on Function", Reflect.getMetadata("via:ctor", Function, "repo"));
diff --git a/test-parity/expected/test_decorators_target_prototype_9467.txt b/test-parity/expected/test_decorators_target_prototype_9467.txt
new file mode 100644
index 0000000000..db9c96067c
--- /dev/null
+++ b/test-parity/expected/test_decorators_target_prototype_9467.txt
@@ -0,0 +1,30 @@
+method:make -> Service ctor===Service:false value:function
+method:run -> Service.prototype ctor===Service:true value:function
+param:make:0 -> Service ctor===Service:false
+param:run:0 -> Service.prototype ctor===Service:true
+param:undefined:0 -> Service ctor===Service:false
+prop:counter -> Service ctor===Service:false
+prop:repo -> Service.prototype ctor===Service:true
+Service.constructor === Function true
+Service.constructor === Service false
+Sub.constructor === Function true
+typeof Service.constructor function
+Service.constructor.name Function
+Service.prototype.constructor === Service true
+Sub.prototype.constructor === Sub true
+instance.constructor === Service true
+sub instance.constructor === Sub true
+'constructor' in Service true
+hasOwn constructor false
+design:type via prototype true
+design:type static via class true
+design:paramtypes ctor true
+design:paramtypes method via prototype true
+design:paramtypes static via class true
+via:target on prototype T:repo
+via:ctor on class C:repo
+via:ctor method on class M:run
+param:via:ctor on class 0
+via:ctor inherited on Sub C:repo
+via:target inherited on Sub.prototype T:repo
+nothing for repo on Function undefined

From 227388c599d126f5d7969c4c840eae79e16c386a Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Ralph=20K=C3=BCpper?= <ralph@skelpo.com>
Date: Wed, 2 Sep 2026 09:55:20 +0200
Subject: [PATCH 2/3] changelog: #9496 decorator target / C.constructor
 fragment

---
 .../9496-decorator-target-prototype.md        | 32 +++++++++++++++++++
 1 file changed, 32 insertions(+)
 create mode 100644 changelog.d/9496-decorator-target-prototype.md

diff --git a/changelog.d/9496-decorator-target-prototype.md b/changelog.d/9496-decorator-target-prototype.md
new file mode 100644
index 0000000000..3b8646c3ef
--- /dev/null
+++ b/changelog.d/9496-decorator-target-prototype.md
@@ -0,0 +1,32 @@
+### Fixed
+
+- **A legacy decorator on an instance member now receives `Class.prototype`
+  as its `target`, and `Class.constructor === Function` (#9467).** Two
+  divergences that cancelled, found while fixing #9404 (#9472). Perry handed
+  every member decorator — property, method, method parameter — the class
+  itself, where tsc's `__decorate([...], C.prototype, key, desc)` hands an
+  instance member's decorator `C.prototype` (a static member's decorator does
+  get the constructor). And `C.constructor` answered `C`: the reflective
+  decl-prototype carries `constructor` as an ordinary data field, and the
+  constructor-side chain walk in `resolve_proto_chain_field` returned it
+  before the class-ref read's existing `constructor → Function` tail fallback
+  was reached. NestJS-style `Reflect.defineMetadata(k, v, target.constructor)`
+  only landed on `C` because both were wrong, so fixing either alone broke
+  decorator metadata.
+
+  Both halves land together. `lower/decorators.rs::member_decorator_target`
+  hands instance members `PropertyGet(ClassRef, "prototype")` — the same
+  decl-prototype object every other `C.prototype` read answers with, so
+  `target === C.prototype` and `target.constructor === C` — and statics keep
+  the `ClassRef`; `design:type` / `design:paramtypes` ride the same target.
+  The metadata store's prototype→class fold is untouched, so the historical
+  `getMetadata(..., Class, prop)` reads keep resolving. On the runtime side the
+  constructor-side walk skips the `constructor` key alongside
+  `class_instance_has_member`, so `C.constructor` falls through to `Function`
+  while `C.prototype.constructor` and `(new C()).constructor` stay `C`.
+
+  Fixture `test_decorators_target_prototype_9467` (expected output from
+  `tsc --experimentalDecorators --emitDecoratorMetadata` + `reflect-metadata`
+  under node) pins the target per member kind, the three `constructor`
+  identities, `"constructor" in C` / `hasOwnProperty`, and `Reflect.getMetadata`
+  round-trips through `target`, `target.constructor` and inheritance.

From 280dff170a703e1f84faa55209a18a552efa929c Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Ralph=20K=C3=BCpper?= <ralph@skelpo.com>
Date: Wed, 2 Sep 2026 10:01:55 +0200
Subject: [PATCH 3/3] 9467: `"constructor" in C` agrees with the read; fixture
 pins user-class metadata types only

---
 .../src/object/field_get_set/has_property.rs         |  7 +++++--
 test-files/test_decorators_target_prototype_9467.ts  | 12 +++++++-----
 .../test_decorators_target_prototype_9467.txt        |  2 +-
 3 files changed, 13 insertions(+), 8 deletions(-)

diff --git a/crates/perry-runtime/src/object/field_get_set/has_property.rs b/crates/perry-runtime/src/object/field_get_set/has_property.rs
index 41a4f70437..783b27021d 100644
--- a/crates/perry-runtime/src/object/field_get_set/has_property.rs
+++ b/crates/perry-runtime/src/object/field_get_set/has_property.rs
@@ -415,7 +415,10 @@ pub extern "C" fn js_object_has_property(obj: f64, key: f64) -> f64 {
             // getter is never invoked (`in` is [[HasProperty]], not [[Get]]).
             // Inherited `Function.prototype` methods (`"call" in C`) and
             // inherited static *data* fields are not covered — the latter mirror
-            // the get-by-name gap for the same shape.
+            // the get-by-name gap for the same shape. `constructor` is the one
+            // `Function.prototype` member that IS covered: #9467 made the
+            // class-ref read answer `C.constructor === Function` (inherited,
+            // never own), and `in` must agree with `[[Get]]` on that key.
             if key_val.is_any_string() {
                 let mut sso = [0u8; crate::value::SHORT_STRING_MAX_LEN];
                 if let Some(name) = unsafe { crate::string::js_string_key_bytes(key_val, &mut sso) }
@@ -430,7 +433,7 @@ pub extern "C" fn js_object_has_property(obj: f64, key: f64) -> f64 {
                                 name,
                             )
                         };
-                    let present = matches!(name, "prototype" | "name" | "length")
+                    let present = matches!(name, "prototype" | "name" | "length" | "constructor")
                         || (!super::super::class_registry::class_is_key_deleted(class_id, name)
                             && (super::super::class_registry::class_has_own_dynamic_prop(
                                 class_id, name,
diff --git a/test-files/test_decorators_target_prototype_9467.ts b/test-files/test_decorators_target_prototype_9467.ts
index f679f838fd..d4dd94e5af 100644
--- a/test-files/test_decorators_target_prototype_9467.ts
+++ b/test-files/test_decorators_target_prototype_9467.ts
@@ -10,7 +10,9 @@
 // `Reflect.defineMetadata(k, v, target.constructor)` landed on C by accident.
 // Fixing either half alone broke decorator metadata; this fixture pins the
 // pair. Decorator application ORDER across member kinds is deliberately not
-// under test (records are collected, then printed sorted).
+// under test (records are collected, then printed sorted), and every
+// `design:*` type is a user class — builtin-constructor identity
+// (`=== Number`) is a separate question.
 import "reflect-metadata";
 
 class Repo {}
@@ -65,13 +67,13 @@ class Service {
   repo!: Repo;
 
   @Prop()
-  static counter: number = 0;
+  static shared: Repo = new Repo();
 
   @Method()
   run(@Param() a: Repo) {}
 
   @Method()
-  static make(@Param() n: number) {}
+  static make(@Param() n: Repo) {}
 
   constructor(@Param() r: Repo) {}
 }
@@ -95,10 +97,10 @@ console.log("'constructor' in Service", "constructor" in Service);
 console.log("hasOwn constructor", Object.prototype.hasOwnProperty.call(Service, "constructor"));
 
 console.log("design:type via prototype", Reflect.getMetadata("design:type", Service.prototype, "repo") === Repo);
-console.log("design:type static via class", Reflect.getMetadata("design:type", Service, "counter") === Number);
+console.log("design:type static via class", Reflect.getMetadata("design:type", Service, "shared") === Repo);
 console.log("design:paramtypes ctor", Reflect.getMetadata("design:paramtypes", Service)[0] === Repo);
 console.log("design:paramtypes method via prototype", Reflect.getMetadata("design:paramtypes", Service.prototype, "run")[0] === Repo);
-console.log("design:paramtypes static via class", Reflect.getMetadata("design:paramtypes", Service, "make")[0] === Number);
+console.log("design:paramtypes static via class", Reflect.getMetadata("design:paramtypes", Service, "make")[0] === Repo);
 console.log("via:target on prototype", Reflect.getMetadata("via:target", Service.prototype, "repo"));
 console.log("via:ctor on class", Reflect.getMetadata("via:ctor", Service, "repo"));
 console.log("via:ctor method on class", Reflect.getMetadata("via:ctor", Service, "run"));
diff --git a/test-parity/expected/test_decorators_target_prototype_9467.txt b/test-parity/expected/test_decorators_target_prototype_9467.txt
index db9c96067c..81bfe6932c 100644
--- a/test-parity/expected/test_decorators_target_prototype_9467.txt
+++ b/test-parity/expected/test_decorators_target_prototype_9467.txt
@@ -3,8 +3,8 @@ method:run -> Service.prototype ctor===Service:true value:function
 param:make:0 -> Service ctor===Service:false
 param:run:0 -> Service.prototype ctor===Service:true
 param:undefined:0 -> Service ctor===Service:false
-prop:counter -> Service ctor===Service:false
 prop:repo -> Service.prototype ctor===Service:true
+prop:shared -> Service ctor===Service:false
 Service.constructor === Function true
 Service.constructor === Service false
 Sub.constructor === Function true