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.
The undeclared properties a checked record keeps from its source, and the
entries of an `unknown` index signature, now follow SerializeJSONProperty:
toJSON runs with the member's key, getters are read, a Buffer becomes its
{ type, data } form, undefined, function and symbol results are dropped,
and a circular structure throws the circular-structure TypeError instead of
overflowing the stack. Members whose writing cannot run program code are
written directly; the others go through the JSON.stringify protocol walk.
Index-signature entries are written from the overflow map in place,
without building a key array.
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.
On Linux, a worker thread that exits without having made any object it
allocated reachable from another thread gives back all of its memory: the
pages it carved, including ProgramLifetime instances and other objects it
never freed, and the system blocks it still holds. The memory goes back
once no other worker thread is running, so that returning it does not slow
the workers that are still running.
A worker carves past each slice's frontier while the arena's free lists and
returned regions are set aside, takes from those free lists only once a
slice has no bump room left, and records the system blocks it allocates.
Messages and intern tables that share published graphs by pointer, and the
process-wide key arrays of typed records, mark the thread as sharing; so
does a remote free of one of its blocks. A worker that did not share parks
with its arena claimed and its discard queued: returning pages makes the
kernel interrupt every running thread of the process to flush its TLB, and
glibc's trim locks the arenas other threads allocate from. The last worker
to park starts one helper that returns each queued worker's pages, frees
its system blocks, and restores its arena to its state at the claim, with
the free blocks the worker took free again. A thread that finds every arena
claimed runs the queued discards itself. A worker that shared keeps its
memory as before.
SCR_SA_DISCARD=0 keeps every worker's memory; SCR_SA_DISCARD=poison makes
the discarded pages inaccessible instead, for tests.
Buffer.concat lowered only a statically typed Buffer[]/Uint8Array[] list
or an array literal. Any other list, such as JavaScript's
`const chunks = []`, reached an SC2020 fence at run time. Such lists now
go to the runtime, which checks them as Node does (an Array whose
elements are Uint8Arrays, ERR_INVALID_ARG_TYPE with Node's messages
otherwise) before concatenating; the length form is covered as well.
scr_mt_tick removes a fired entry only while it is still the queue's
first entry, as Node's MockTimers.tick does. A callback that queues an
entry sorting before it, such as an immediate due at now - 1, leaves the
fired timer queued, so it runs again, as it does in Node. The comment
now says so and names the fixture that checks the order against Node.
packages/runtime/test/common-symbols.test.ts requires runtime globals to
be definitions, not tentative definitions that some toolchains emit as
common symbols; scr_uncloneable_count now starts at 0 explicitly.
ThreadSlots<K, V> holds one value per key and thread, like a WeakMap that
each thread has its own copy of; under Node.js it is a WeakMap per name
and thread. Setting a value never writes the key, so values can be set on
published keys.
Classes used as keys carry a 32-bit slot word after their header words,
assigned on the first set for a key (with a compare-and-swap for a
published key) and never reused. Each family has one block per thread
that maps slot indices to values through pages of 1024 entries. get and
has are inline reads of the slot word, the page and the entry; set and
delete call scr_slots.c, which holds one reference to each value. A key
class's free paths release the key's values, and thread exit releases the
rest.
Errors that reach checked-dynamic code are objects carrying the reserved
"%error" marker, with name and message either own or on their prototype.
Several string conversions handled them differently from Node:
- `"" + error`, `error + ""` and `error == "TypeError: ..."` converted
through the plain-object path and answered "[object Object]".
- Template literals and Array join read name and message as own members
only, so a builtin error whose name is inherited printed its message
alone.
- String(error) used the native error, which did not see name and message
assigned through the dynamic view.
scr_dyn_error_string implements Error.prototype.toString over the
encoding, reading both members through the prototype, and the template
renderer, Array join, ToPrimitive, ToString and the numeric conversion use
it. Assigning a string name or message through the dynamic view now also
updates the native error, as assigning stack and cause already did.
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.
A cycle pass tears down its dead set in the order the walk found it, so
the LIFO free lists handed the blocks of a large dead structure to the
next allocations scattered over every page it used, and the structures
built from them missed the cache on most objects. Sets of at least 16384
objects are now torn down in descending address order
(scr_mem_order_for_free, a bitmap of block indices per size class), so the
free lists hand the blocks back in ascending order, the order the bump
pointers carve fresh memory in.
A full pass takes every candidate buffer, so markGray now clears each
reached object's buffered mark in the header write it makes anyway,
instead of a separate loop over the candidates.
The util.types brands answered isFloat16Array with false for every value.
Float16Array now answers it from the value's storage kind, ahead of that
probe, so this drops the unreachable entry and the declaration that
returns boolean.
LLVM's WebAssembly pass that gives multiple-entry loops a single entry
first records, for every block, every block it can reach. Its time and
memory grow with the square of a function's block count even when the
function has no such loop. In the three.js nodes fixture a module
initializer of 40,000 blocks spent four minutes and 22 GB in it, which
set the helper's peak and most of its wall time.
The helper now runs the pass only on functions whose control flow graph
is irreducible, and WebAssembly object emission leaves out the module
pass that collects external symbols for assembly declarations, so each
function's machine code is freed once it is printed. Optimized
partitions are compiled through the thin backend's pre-codegen hook to
use the same pipeline. Objects are unchanged.
check_discard ran trim_allocate again for its returned-regions case, which
writes the blocks into trim_blocks, the array check_trim had freed. Where
glibc maps an 8 MB block by itself (its adaptive mmap threshold, which the
allocator's heap policy leaves alone unless transparent huge pages are in
madvise mode), the free unmaps it and the worker thread's first write
faults. The case now allocates the array again and frees it.
The check that a worker takes the free blocks set aside compared the
highest block it carved with that of the worker before it, which took its
blocks from free lists below the slice's frontier, and it passed when a
worker never took them. Each run now counts the blocks it allocates past
the highest block of the class so far: at most the bump room the slice had
left, against all of them when a worker does not take the free blocks. The
residency bound after a discard allows for pre-fault requests still in
flight.
querystring.parse and querystring.decode build their result with a null
prototype, as Node does: util.inspect prints the [Object: null prototype]
base, Object.getPrototypeOf answers null, ToPrimitive throws a TypeError,
and Object.prototype methods are not reachable through the result.
An inline JavaScript callback receives a matchAll row as a dynamic
array. The groups projection now reads its captures through dynamic
index reads, and throws Node's TypeError for null and undefined rows.
Rows kept by filter, slice, toReversed and toSorted, or picked by find,
findLast and at, trace to the drain's regex; a reassigned callback
parameter does not. { groups } patterns serve dynamic rows and pattern
parameters. The groups record has a null prototype.
maybeNarrow takes the receiver's declared shape from its non-nullable
type, so a JavaScript read of a nonparticipating group keeps its
undefined arm instead of narrowing to string.
`"method" in instance` on a class instance held as `any` answered false
for the class's methods, getters and setters when the program also uses
instanceof or Object.getPrototypeOf on the class. Those uses attach the
class's prototype data to the instance's snapshot, and that object holds
only the methods the program reads through the prototype; the literal-key
`in` then searched it instead of the class.
When a literal key names a method or accessor of a boxed class with
prototype data, the class dynamic-dispatch pass now evaluates `in`
through the computed-key form, which answers class members from the class
itself.
renderDiagnostics printed every frame line whole and rebuilt the
file's line index for each diagnostic. On minified sources with
thousands of diagnostics the joined report exceeded V8's string length
and `scriptc coverage` crashed with RangeError: Invalid string length.
Frame lines longer than 400 characters now show a 400-character window
around the diagnostic's column, with "…" where text is cut, and the line
index is built once per file. Every diagnostic is still rendered.
Closes#201
Co-authored-by: Max B <32987678+techfreaque@users.noreply.github.com>
Chris Tate