Real npm Packages Now Compile: axios, zod, express — and a Conformance Sweep

The last post ended at v0.5.875 with the GC story — closing the gap aya_koto's benchmark exposed. That post was about winning one benchmark. This one is about a different kind of work: the roughly 270 releases between v0.5.875 and v0.5.1146, landed over about four weeks, almost none of which are benchmark headlines. The theme shifted from “go fast on a microbenchmark” to “make real-world TypeScript and real npm packages actually compile and run.” Plus a full Windows visual overhaul and a pile of new widgets along the way.

Here's what shipped, grouped by what it was actually for.

Real npm packages compile now

The biggest single thread through this window is a sweep to make popular npm packages compile to native binaries and pass behavioral tests — not just “link without errors,” but run and produce the right output. The list that now works through perry.compilePackages includes axios, jose, zod v4, vitest, express, fastify, @hono/node-server, dayjs, chalk, ms, debug, lodash, ethers, argon2, and Colyseus.

Each one failed for its own reason, and each fix is its own small story:

• zod v4 crashed with Cannot read properties of undefined (reading 'onattach'). Root cause (v0.5.1144, #4698): new F() where F is a function imported from another module silently produced an empty object — the constructor body never ran, so every $ZodCheckMinLength-style check came back stripped of its _zod property.
• axios + jose needed crypto and compression Perry didn't have yet: zlib.createBrotliDecompress, crypto.subtle.wrapKey/unwrapKey, subtle.generateKey / encrypt / decrypt for AES-GCM, and randomFillSync (v0.5.972–976).
• fastify was deadlocking on a one-second polling timeout in wait_for_promise; we replaced it with a condvar wait and made rejected promises surface as HTTP 500 instead of hanging (v0.5.912).
• @hono/node-server couldn't read a POST body — c.req.text() / .json() / .formData() returned empty on POST/PUT until a parent-registration fix in v0.5.1142.
• chalk, ms, debug, express all hit the same shape: a callable value with properties attached (chalk.red, express() plus express.Router). Three flavors of that pattern got fixed across v0.5.935 and the surrounding npm sweep, plus util.inherits + a stream prototype scaffold to unblock express (v0.5.990).
• dayjs, shipped as a minified bundle, exercised JS-classic prototype-method dispatch (Class.prototype.m = fn) that Perry lowered wrong (v0.5.924/932).

Underneath all of that sits the part that makes packages Perry can't compile natively still run: the V8-fallback runtime got real this window. Its ModuleLoader now reads from an embedded module map, so a fallback binary is still self-contained — no loose node_modules at runtime (v0.5.994). createServer bridges to a real hyper server (v0.5.999), and Response / Request / Headers Web Fetch globals exist in the fallback path (v0.5.1006). And compile-time dynamic import() — string-literal await import('./foo.ts') resolved at build time — finally landed (v0.5.905, #100).

A test262 conformance sweep

The other dominant thread is conformance. We ran focused passes against the test262 subset radars and moved the needle on the built-ins that real code leans on hardest:

built-ins/String         60.2% → 79.3%   (v0.5.1128)
built-ins/Array          61.5% → 72.5%   (v0.5.1127)
language/.../destructuring 41.6% → 53.9%  (v0.5.1143)

The String jump came from giving every String.prototype method generic-this dispatch and fixing slice/substring index coercion. The Array jump was thisArg on the dense-array callbacks (forEach/map/filter/…), array-like ToLength, spec operation ordering, and zero-argument validation. Destructuring picked up parameter-destructuring across plain, generator, async-generator, static, and private class methods.

Alongside the headline numbers, a long tail of correctness landed: JSON.parse now throws a real SyntaxError (not a TypeError) and rejects trailing tokens; its reviver walks via the spec InternalizeJSONProperty algorithm; Object.prototype.toString brands correctly for typed arrays, Symbol, BigInt, Map/Set/WeakMap/WeakSet/Promise/RegExp; RegExp.prototype.toString returns /source/flags; async generators got their yield-awaits-operand semantics right. These are subset radars, not the full suite — Perry is still climbing — but the climb this month was steep.

Windows goes Fluent

Windows got a visual overhaul (the #4681 series). Perry windows now opt into the modern DWM chrome by default — Mica backdrop, rounded corners, and a theme-aware title bar — and the common controls render through comctl32 v6 instead of the Windows 95-era defaults. The window proc now handles WM_DPICHANGED, so a window stays crisp when you drag it between monitors with mixed scaling instead of getting bitmap-stretched.

Crucially, none of this reintroduced the old #1542 “black area after resize” regression: the client area is still painted opaque, and full-frame Mica/Acrylic blur-through stays an explicit app.setVibrancy(...) opt-in. There's also a new --target windows-winui backend scaffold (WinUI 3) for apps that want the fully modern stack, and a small but real fix that makes perry compile main.ts -o main produce main.exe on Windows so PowerShell will actually launch it (v0.5.1146).

New widgets, every platform

Two widgets landed in just the last day, and both span every UI platform Perry targets:

• DatePicker (#4772) — a compact, field-style date control: NSDatePicker on macOS, UIDatePicker (.compact) on iOS/visionOS, SysDateTimePick32 on Windows, android.widget.DatePicker on Android, GTK4 on Linux. One TS surface across all of them.
• Drag & drop (#4773) — any widget can be a drop destination and a drag source for text/files/URLs, mapped to NSDraggingDestination (AppKit), UIDropInteraction (UIKit), and View.setOnDragListener (Android).

import { DatePicker } from "@perry/ui";

DatePicker(2026, 6, (iso) => {
  // iso is a POSIX-locale "yyyy-MM-dd" string
  console.log("picked", iso);
});

Earlier in the window the widget shelf filled out across desktop and mobile too — Combobox, TreeView, Calendar, Chart, CommandPalette, RichTextEditor, MapView, PdfView, BottomNavigation, and a swipeable ImageGallery — each backed by the real native control on every platform. HarmonyOS (ArkTS) got Chart and TreeView (v0.5.893), the last two widgets it needed to reach parity with the others.

GC, internals, and stability

Most of those 270 releases are not headlines — they're bug fixes and internals, and that's the point of this phase. A few worth calling out:

• GC continued. The conditional free-list work from the GC post kept settling in, and a sharp class of bug got closed: native-bridged Promises are now pinned while in flight on a tokio worker so the GC can't sweep them before resolution lands (v0.5.923). If you ran an async fetch under load and saw a phantom collection, that was this.
• The memory model is documented. There's now an internals/memory-model.md deep-dive — NaN-boxing, the generational GC, the shadow stack, and write barriers — wired into the docs site (v0.5.933).
• A wave of codegen stability fixes surfaced by the npm sweep: a module-level const arrow called inside a resumed async step no longer SIGSEGVs (v0.5.953), try { await rejected } catch { return X } no longer hangs forever (v0.5.870), and a handful of js_is_truthy / raw-pointer-range crashes that real bundles tripped.

Apple housekeeping

Smaller but real: perry setup ios --development now provisions for development builds (v0.5.1023), and the Apple cross-library build/link path was deduplicated and made pointer-width-portable (v0.5.1121/1125) — which is what unblocked the npm / Homebrew / APT / winget publish matrix that had been wedged.

Where this leaves things

The bet behind Perry has always been that “native TypeScript” only matters if real TypeScript runs — not a toy subset, the actual packages people npm install. This month was mostly that work: less a single number to brag about, more a long, unglamorous push to close the gap between “compiles” and “works.” The conformance radars and the npm parity tests are the scoreboard we're watching now, and we'll keep posting the numbers — the good and the still-imperfect.

Source: github.com/PerryTS/perry — Issues: github.com/PerryTS/perry/issues

— Ralph