A class binding may hold a subclass of the class it was declared with.
When the declared class has subclasses, a caught payload of that class is
now tested against the class the binding holds, as for other operands, so
a base-class instance no longer passes a test against a subclass.
The reflection gate turned on only for an untyped or Error-shaped
defineProperty target, so a helper taking `target: object` (or `{}`,
`Object`, a weak type, or a type parameter) installed a message or name
accessor that typed Error reads then skipped, returning the old slot
value. The gate now turns on for any target an Error may flow into: an
untyped or generic type, a type Error is assignable to, or an
Error-shaped type, alone or in a union or intersection.
e instanceof E where e is a catch binding and E a binding holding a class expression (var E = class extends Error {}) refused with "'instanceof' right-hand sides other than classes declared in the program". The binding holds exactly that class, so the test is the class's caught test (hono's SmartRouter fallback on UnsupportedPathError).
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
entries(), keys() and values() on a checked-dynamic Headers value threw 'is not a function'. They now return live native iterators over the sorted header list, re-read on every step with set-cookie values one by one, as Node's Headers iterator does (hono's Context copies response headers this way).
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Worklist passes that transform every function (the class-construction dispatch rewriting dyn.classBasePrototype) rebuild statement objects, so a recorded lazy bag store could be a detached copy. When the class gained prototype data later, only the copy was upgraded and the live store kept creating a bare {} bag: inherited methods read as undefined through the property bag (hono's SmartRouter.match once zod was in the program). Upgrades now also reach the stores as they stand in the generated bodies.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
An implicit-any package function specialized for a string argument lowered base?.[0] to the element-access refusal: the checker types the receiver any, so only the lowered string reached the string-index path. Hono's mergePath failed at startup.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
s.match(p) and s.search(p) with an untyped pattern now choose at run time, as Node does: a RegExp is used as is (with its lastIndex state), any other value builds new RegExp(value). The checked-dynamic receiver form previously threw 'method calls like path.match on a string are not supported yet' (hono's RegExpRouter matcher).
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
A package function declared to return its own type parameter, which also
types one of its parameters (<T extends object>(obj: T) => T), hands back
the argument or something standing in for it, and the package may track
that object's identity. Effect's Equal.byReference returns a proxy it
keeps in a WeakSet. The declaration-typed boundary cast such a result to
the argument's type and built a separate native record, so
Equal.equals(a, b) on two by-reference objects compared them by value and
printed true where Node prints false. The result's type comes from the
caller's argument, not from data the package declares, so the projection
no longer casts these calls.
The package re-export coverage test now expects three dynamic statements:
since the boundary, readRows's declared number result keeps its type, so
count - 1 in 7004-package-declared-type-reexports is native arithmetic.
The prototype object of a function-local class, created once per evaluation
of the class, now starts with its own non-enumerable `constructor`, the
class value of that evaluation, as every class prototype does. Reflecting
the prototype of a function-local class without prototype members exposed
an object without it: `proto.constructor` answered the base class, and
`Object.hasOwn(proto, "constructor")` and its property descriptor did not
match Node.
zod 4 defines its error message with Object.defineProperty(inst, "message",
{ get, set }). The typed-ref commit of an Error subclass read the accessor
as a data value and threw "expected string". The commit and the slot sync
now leave the slot alone and mark the property absent; typed reads and
writes of name and message call the accessor when the program reflects on
an untyped or Error-shaped target.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Object.getPrototypeOf on an instance of a function-local class refused
unless its prototype members were installed at run time. A class that
declares no prototype methods or accessors (zod 4's
class Definition extends Parent {}) has nothing to install, so its shared
prototype view is returned, as is a bare Local.prototype value.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
A JavaScript package function lowered once per argument-type tuple
collects its local class per instance. A function hoisted above the class
statement in a later instance resolved the class an earlier instance
collected (zod 4's $constructor: "expected class constructor"). It now
takes the forward-class TDZ box unless the collected class is this
instance's.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
A fresh array literal wrapped in parentheses or `satisfies` on the right
side of a write to a member of a typed view of the global object
(`g.cache ??= ([])`, `g.cache ||= [] satisfies number[]`) is now built as
the declared native array too, so typed reads return the same array.
globalViewSlot walks up through those wrappers to the write's right operand
and answers it, and the slot type comes from that operand's contextual type.
- A bare arrow parameter after `async` (`async x => ...`) gets parentheses
with its projected type, as `x => ...` does. Without them the rewritten
file failed its check and lost its projection (SC6102).
- A cast that starts an unbraced loop or `if` body gets no `;` guard. Only
a statement in a statement list can continue the previous line, and in
a body the `;` became the body, which moved the statement after the
loop.
- Adoption walks a tuple's elements through the live element capsules of
the tuple's view, so references package code holds to them see the
native values.
- scr_runtime.h declares scr_dyn_decl_adopt (in scr_dyn.h), which the
backend emits, so llvm-runtime-abi.test.ts finds its prototype.
- npm.test.ts gives zod3-adoption and zod3-boundary the long per-case
timeout of the other zod 3 cases; their sanitized builds compile zod's
types module too.
Any computed write with a key TypeScript cannot know (zod's
`curr[el] = ...` in ZodError.js, for one) puts every class method name
in the method census. Every typed call of such a method then went
through the observable prototype slot: a dynamic call with boxed
arguments, followed by a checked conversion of the result (for a
`Product[]` result, a deep walk of every element). Bundling untyped
JavaScript made unrelated typed code several times slower per call.
The prototype data now keeps each observed method's original value in a
global. A typed, non-virtual call of a TypeScript method still reads the
slot first, as before, and calls the method natively when the slot holds
that original value. A replacement, on the prototype or as an own
property, still takes the dynamic call. Virtual calls and methods
declared in unchecked JavaScript keep the dynamic call.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
A fresh array literal written to a checked-dynamic slot is built as a
dynamic array. On a member of a typed view of the global object
(`(globalThis as typeof globalThis & { cache?: number[] }).cache ??= []`)
the program reads it back through that declaration, and each typed read
extracted a new native copy. `cache().push(x)` was lost, and two reads
were never the same array. Node keeps one array.
When the literal is the right side of a write (`=`, `??=`, `||=`) to a
member of the global object, and the member is declared as a native
array, build the native array and store it boxed. Every typed read then
extracts that same array, and untyped reads see it through its live
capsule.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
BigInt of byte storage joined the elements with "," for every kind, so a
Buffer, whose text is its UTF-8 decoding, and a DataView, whose text is
"[object DataView]", converted as typed arrays. BigInt now parses the
value's ToString, which the runtime value decides, as String does. This also
covers a Buffer held in a Uint8Array slot.
Corpus 7403 adds Buffers, a DataView, and a Buffer in a typed array slot.
Refs #1647
Chris Tate