A require cycle was always refused (SC1016). Node answers a require of a
module that is still evaluating with its exports as they stand, while the
compiled bindings alias the final declarations; the two agree when every
module of the cycle assigns all of its exports before its first statement
that can run another module's code, every other use of its export object
is a plain member read, and no module's top-level code can reach its
binding of another member. Each module then initializes exactly as it
would outside the cycle. This admits semver's comparator/range cycle
("hoisted class for cyclic dependency"); other cycles keep SC1016 with a
reason naming the offending statement.
The require reachability scan no longer treats a declaration's own name
as a read (esbuild's `var X = class {...}` before its requires), treats a
plain write of an export member as running only a setter published for it
(on-finished's `module.exports.isFinished = isFinished`), and keeps the
conservative scan for writes of __proto__, __esModule and members of a
replaced export object.
Evidence: corpus 6145 (the cycle), 6142 gains the esbuild layout; the
npm-static harness compiles the published fs.realpath@1.0.0,
on-finished@2.4.1 (with ee-first@1.1.1) and statuses@2.0.1 statically;
program.test.ts pins the TDZ analysis through var bindings plus the cycle
admission and refusals. Preflight/order baselines recorded for the new
fixtures; a full re-record changed no other fixture. Dependencies and
limitations docs describe the supported require forms.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
superCallStmt asserted the class base before checking for a callable
base. A class that extends an ordinary function constructor has no base
class info, so the assertion held null. Node ignores the unused value;
the native compiler throws the TypeError of a non-null assertion that
held null, and failed to compile programs with such classes (for example
the Effect stream fixtures). The base is now read after that case
returns.
Reads of defaultMaxListeners through an ES module namespace import or a
named import answer the namespace's copy of the export, which keeps its
value from program start until module.syncBuiltinESMExports() refreshes it,
as in Node. The default import, the EventEmitter class and CommonJS module
bindings keep reading the current default. A destructured CommonJS binding
of defaultMaxListeners, which held a placeholder string in JavaScript
files, is refused.
A TypeScript Date placed in an `unknown` slot (an annotated binding, an
object or array literal, a record or class field) becomes a Date holding
the same time value. Before, a Date member of an `unknown` object literal
became a function, and other conversions were refused. util.inspect prints
these Dates in their ISO form or as Invalid Date, and their methods can be
read as values through untyped references. Comparisons with a Date operand
keep their fence: each conversion creates a new Date.
node:test changes, matching Node 24.22:
- t.assert.snapshot(value[, options]) serializes the value with Node's
default serializer, JSON.stringify(value, null, 2), or with an
options.serializers array literal applied in order, and compares it
with assert.strictEqual against the snapshot stored under
"<test full name> <n>" in "<entry file>.snapshot".
- t.assert.fileSnapshot(value, path[, options]) compares the serialized
value with the contents of path.
- Snapshot files are read in the form Node writes them, exports[`key`] =
`value`; statements, with template escapes and CRLF line endings
cooked as in a template literal.
- Missing snapshots, unreadable snapshot files and throwing serializers
throw Node's ERR_INVALID_STATE errors, with Node's messages.
- Running the binary with Node's --test-update-snapshots flag as its
first argument records the values and writes the snapshot files after
the last test, keys sorted as Node sorts them. The flag is kept out of
process.argv and appears in process.execArgv, which is otherwise [].
- Snapshot assertions count toward the test's plan.
The snapshot fixture compares the reporter output with Node, plain and
with SCRIPTC_SAN=1, against a snapshot file Node wrote. The update-mode
harness test runs Node and the binary with --test-update-snapshots and
compares the files they write. The node:test normalization also drops
the "... N lines matching cause stack trace ..." line Node prints for an
error cause, with the stack frames it summarizes.
markAsUncloneable(value) marks a plain object, a record, an error or a
class instance (scr_json.c); structuredClone and postMessage then throw
DataCloneError "Cannot clone object of unsupported type." for it, also
where it is nested. As in Node, the mark has no effect on primitives,
arrays, typed arrays and ArrayBuffers. Marked values are retained until
the thread exits; with nothing marked, the clone paths add one branch.
worker[Symbol.asyncDispose]() terminates the worker and resolves with
undefined after its 'exit' event, so `await using` disposes a Worker at
the end of its block. The Worker handle's symbol_get op answers the
well-known symbol: the symbol unit registers Symbol.asyncDispose with the
dyn core when the program names it, and scr_dyn_is_async_dispose_symbol
tells the worker unit, so worker programs that never name the symbol do
not link the symbol unit.
static-support.json adds rows for markAsUncloneable, isInternalThread
(already lowered as false and declared) and worker[Symbol.asyncDispose]().
Corpus 5990-5991 match Node v24.22.0; corpus-costs.json records their
costs.
Regex literals and new RegExp calls accept the v (unicode sets) flag, which
the vendored engine implements: class subtraction and intersection, nested
classes, \q{...} string literals and properties of strings. The flag uses
unicode mode for pattern decoding and string iteration, and flags read in
getter order (dgimsuvy). Regex literals now also report their flags in
getter order, as Node does for /x/yg, and the flag getters (global,
unicodeSets and the rest) compile on statically typed regexes.
In v mode the engine rejected `-` and doubled punctuation outside a
character class, and the `\-` escape inside \q{...}. It now applies the
class-only checks inside classes and \q{...} only, and parses \q{...}
contents with the class escapes, matching Node. The d flag is still
refused.
d.toJSON() now answers the toISOString() string for a valid date and
null for an invalid one, as a string | null value although the lib
types say string. Unannotated bindings, object and array literal
entries initialized by it keep the null, reads of such bindings stay
checked, and JSON.stringify serializes the null instead of narrowing
it to string.
Closes#935
Co-authored-by: phall <25888173+phall1@users.noreply.github.com>
An async generator that fell off its end, with a return type other than
void, settled its last next() one microtask turn after Node, so for await
loops over it also ended a turn late. The appended implicit return now
marks the completion as settled, like a bare `return;`.
return() at a suspended yield ran the generator's finally blocks before
awaiting the return value. The request now awaits the value first and
resumes the body on the next turn, and the completion that follows settles
without a further turn, also when a finally block yields or awaits first.
An explicit `return x` reached during that unwind still takes its own turn
to await x.
Array.fromAsync accepts typed async generator sources: each next() result
is awaited and its value used as is, a throwing or rejecting mapping
function closes the generator, and a rejected next() rejects the result on
the turn Node rejects it.
Float16Array is a native typed-array kind with IEEE 754 binary16 storage.
Stores round the number to nearest-even in one step from the double, as
Node does, including overflow to Infinity, subnormals, -0 and NaN; reads
widen exactly. The runtime converts with integer operations, so no target
needs half-precision hardware or compiler-rt support.
Construction, element reads and writes, ArrayBuffer views, fill, set,
subarray, slice, both sort orders, constructor values and checked-dynamic
storage work as for the other typed arrays. Math.f16round,
DataView.prototype.getFloat16 and setFloat16, and util.types.isFloat16Array
compile.
new DisposableStack() compiles to a native stack handle. use, adopt, defer,
move, dispose, disposed and [Symbol.dispose] are members of its dynamic
view, and the stack works with `using`. Disposal runs the resources in
reverse order, calls use() resources' dispose methods with the resource as
`this`, and raises a SuppressedError chain when more than one disposal
throws; a single failure is rethrown as thrown. Calls on a disposed stack
throw Node's ReferenceError, and invalid receivers, resources and
callbacks throw Node's TypeErrors.
use() of a class instance registers a function that calls the class's
[Symbol.dispose] method, and returns the instance at its static type; use()
of a union that includes class instances is refused. The stack is
collected with its callbacks when a callback captures the stack.
x instanceof DisposableStack compiles. Handles can expose symbol-keyed
members through a new symbol_get hook.
After socket.setEncoding("utf8"), Node passes strings to 'data'
listeners, while @types/node types the chunk as a Buffer. An inline
listener whose chunk is typed Buffer (annotated or inferred) received a
Buffer. When a program can call setEncoding on a socket, such listeners
now take the chunk as a checked dynamic value, so console.log, typeof,
string methods and concatenation behave as in Node, and Buffer-only
methods throw Node's TypeError. Programs without setEncoding on a socket
compile to the same IR as before.
The ESNext error lib is now part of the type world, and Error.isError(value)
compiles. A catch binding tests its payload against the Error class, an
unknown value tests the checked-dynamic error encoding, and a union tests its
runtime tag against the arms whose class extends Error. Other values answer
statically: true for instances of Error and its subclasses, false for
everything else, including objects that only have an error's shape. The
argument is always evaluated. Unions with unknown arms are refused.
TypeScript class fields declared `unknown` or `object`, also with `null`
or `undefined` or as arrays of those, were refused with SC1090. They now
use the checked-dynamic storage that JavaScript class fields without a
declared type already use. This covers instance fields, static fields and
parameter properties. Fields declared `any` stay refused.
Fixes#1147
Co-authored-by: Alan Leal <33952+alantriesagain@users.noreply.github.com>
`Int32` from @scriptc/types now also annotates the element type of a
declared number array (`Int32[]`, `readonly Int32[]`, `Array<Int32>`,
`ReadonlyArray<Int32>`) on parameters, variables, class instance fields
and function results. The contract promises that every element stored
into the array, through any reference, is an int32 by construction.
contracts/int32-elements.ts checks it over a whole-program flow graph of
the places array references live (locals, parameters, globals, results,
class field families, record fields, container element slots), with one
node per allocation and per opaque origin. Allocations that can reach an
annotated slot are constrained and every element store into an array that
may be constrained must be range-proven an int32 (SC7002); element copies
constrain their sources by fixpoint; arrays from or escaping to code the
IR does not show refuse the contract (SC7003). Slots only constrained
arrays reach are recorded as IrContracts.int32Elements.
Element reads that find a value through those slots carry the int32
range, `getNumber` reads are integer-or-NaN operands of wrapping sums, and
ToInt32 of any integer-or-NaN operand is branch-free. Holes, missing
indices and length changes keep their JavaScript behavior.
Integer kernels over a 2^20-element array: `(s + a[i]) | 0` 1086 -> 175 ms,
`(Math.imul(h, 31) + a[i]) | 0` 602 -> 150 ms, prefix sums 575 -> 155 ms;
programs without the annotation compile to identical binaries.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
A structural type that receives class instances became a checked view
for all of its values, even when nothing could tell a copy from the
original. In tsc-ts this turned ResolvedProjectReference, the redirect
parameter of every module resolution, into a checked-dynamic value.
markIdentityFlows still finds every flow, then keeps a type marked only
when the program can observe the difference:
- values of the type are written through, compared by identity (also
inside generic functions), used as Set or Map keys or array search
needles, or passed to whole-object observers or any-value parameters;
- a field the type exposes is written on the source class after
construction, or is an accessor;
- its values flow into another kept view or class-backed protocol.
Other types stay native records.
- JavaScript calls of Promise.withResolvers' resolve/reject through the
record no longer fail with an internal compiler error.
- new RegExp with the d or v flag is refused (SC1120) for literal flags
and throws a named error for computed flags, instead of SyntaxError.
- JavaScript .groups reads on matches whose regex is not traceable are
refused like TypeScript's, instead of reading undefined.
- Iterator helpers on the string iterator are refused instead of
failing at run time.
node:test changes, matching Node 24.22:
- { concurrency } on describe, suite, test, it and t.test sets how many
subtests run at once: a number, true for os.availableParallelism() - 1,
or false for 1. Subtests inherit the parent's value.
- Above 1, each subtest runs on its own fiber. Subtests start in
declaration order as slots free up, and t.test and test() calls inside a
concurrent test start the subtest at once; t.test's promise settles when
it finishes. The parent finishes after all of them.
- Results, diagnostics and failures are reported in declaration order.
- A concurrent subtest waits after its beforeEach hooks, and a concurrent
suite before its children, for as many turns as Node's runner does, so
sibling bodies interleave as they do there.
- A concurrency that is not an integer from 1 to 4294967295 throws Node's
ERR_OUT_OF_RANGE RangeError when the test or suite is created.
- Nested test() calls and hooks inside a concurrent subtest attach to the
subtest that runs on the calling fiber.
The concurrency fixture compares the reporter output, the order of the
bodies' side effects, and the range errors with Node, plain and with
SCRIPTC_SAN=1.
Malte Ubl