Other engines don't give NaN if there is at least one digit after the
dot for milliseconds. We were much stricter and required exactly three
digits.
But there is real world usage of different amounts of digits such as
discord having three extra trailing zeros.
First, this adds a constructor to the Date object to be created from a
plain double. This is a first step to removing Core::DateTime as the
basis for the Date object. A subsequent commit will remove the now-
unused data from the object.
Next, this implements the constructor in accordance to the spec. The
constructor when NewTarget is undefined no longer allocates a Date on
the heap. The other constructor properly uses recently created AOs to
handle time zone and ensure the created [[DateValue]] is valid. Other
methods on the constructor (Date.now) have not been touched yet.
Last, the prototype is reimplemented. Again, we use other AOs to handle
time zones and time clipping. Not all prototypes are fixed; most of them
are, but a few (e.g. Date.prototype.getTimezoneOffset) were not fixed,
but left in a mostly unimplemented state for another commit.
In all of the above, spec comments are added. This is a rather large
change; but it's tough to do any of these parts individually without
breaking everything else.
In commmit 7d2834344a, I think I combined
the definitions of the LocalTZA and UTC AOs in my head, and thought the
offset should be negated within LocalTZA. Instead, the offset should be
left untouched, and the UTC AO is responsible for doing the subtraction.
This fixes all failing Date.UTC test262 tests, which failed due to not
handling invalid input and evaluating inputs out of order. But this also
avoids using timegm(), which doesn't work on macOS for years before 1900
(they simply return -1 for those years).
Partially addresses #4651. Date.parse.js still fails.
Both at the same time because many of them call construct() in call()
and I'm not keen on adding a bunch of temporary plumbing to turn
exceptions into throw completions.
Also changes the return value of construct() to Object* instead of Value
as it always needs to return an object; allowing an arbitrary Value is a
massive foot gun.
The old versions were renamed to JS_DECLARE_OLD_NATIVE_FUNCTION and
JS_DEFINE_OLD_NATIVE_FUNCTION, and will be eventually removed once all
native functions were converted to the new format.
The ECMAScript spec says that Date parsing can support any number of
implementation-defined date formats. So let's support a format commonly
used on the web. And let Core::DateTime do the heavy lifting. :^)
...for the non-success state. This fixes a crash when parsing dates with
the year -1, as we would assert successful parsing ("year != -1").
Mixing Optional and -1 seems worse and more complicated than just using
Optional for all the values, so I did that instead.
It is defined as follows:
21.4.3.1 Date.now ( )
https://tc39.es/ecma262/#sec-date.now
The now function returns the time value designating the UTC date and
time of the occurrence of the call to now.
"Time value" is defined as:
21.4.1.1 Time Values and Time Range
https://tc39.es/ecma262/#sec-time-values-and-time-range
An ECMAScript time value is a Number, either a finite integral
Number representing an instant in time to millisecond precision or
NaN representing no specific instant.
By flooring the value we match the behavior in the Temporal proposal's
Temporal.ZonedDateTime.prototype.epochMilliseconds getter:
4. Let ms be RoundTowardsZero(ℝ(ns) / 10^6).
With that being defined as:
13.30 RoundTowardsZero ( x )
https://tc39.es/proposal-temporal/#sec-temporal-roundtowardszero
1. Return the mathematical value that is the same sign as x and
whose magnitude is floor(abs(x)).
This is makes the last of the currently 15 Temporal tests in test262
work, which compares Temporal.now.instant() with Date.now() :^)
This removes all usages of the non-standard define_property helper
method and replaces all it's usages with the specification required
alternative or with define_direct_property where appropriate.
This makes the implicit run-time assertion in PropertyName::to_string()
into an explicit compile-time requirement, removes a wasteful FlyString
-> PropertyName -> FlyString construction from NativeFunction::create()
and allows setting the function name to a null string for anonymous
native functions.
Some of the code assumed that chars were always signed while that is
not the case on ARM hosts.
Also, some of the code tried to use EOF (-1) in a way similar to what
fgetc() does, however instead of storing the characters in an int
variable a char was used.
While this seemed to work it also meant that character 0xFF would be
incorrectly seen as an end-of-file.
Careful reading of fgetc() reveals that fgetc() stores character
data in an int where valid characters are in the range of 0-255 and
the EOF value is explicitly outside of that range (usually -1).
As mentioned on Discord earlier, we'll add these to all new functions
going forward - this is the backfill. Reasons:
- It makes you look at the spec, implementing based on MDN or V8
behavior is a no-go
- It makes finding the various functions that are non-compliant easier,
in the future everything should either have such a comment or, if it's
not from the spec at all, a comment explaining why that is the case
- It makes it easier to check whether a certain abstract operation is
implemented in LibJS, not all of them use the same name as the spec.
E.g. RejectPromise() is Promise::reject()
- It makes it easier to reason about vm.arguments(), e.g. when the
function has a rest parameter
- It makes it easier to see whether a certain function is from a
proposal or Annex B
Also:
- Add arguments to all functions and abstract operations that already
had a comment
- Fix some outdated section numbers
- Replace some ecma-international.org URLs with tc39.es
Since theres no way to drop the arguments before the call to the
constructor (or to signal to the constructor that it was not called
directly), we simply reuse the code for the no arguments provided
special case. (And to prevent code duplication, the code was extracted
into the separate static function Date::now(GlobalObject&).
When using Core::DateTime::from_timestamp(0) the resulting Date is
1970-01-01 00:00:00 in UTC, which might be something different in local
time - this is incorrect and relevant as invalid Dates can be made valid
later on.
SPDX License Identifiers are a more compact / standardized
way of representing file license information.
See: https://spdx.dev/resources/use/#identifiers
This was done with the `ambr` search and replace tool.
ambr --no-parent-ignore --key-from-file --rep-from-file key.txt rep.txt *
(...and ASSERT_NOT_REACHED => VERIFY_NOT_REACHED)
Since all of these checks are done in release builds as well,
let's rename them to VERIFY to prevent confusion, as everyone is
used to assertions being compiled out in release.
We can introduce a new ASSERT macro that is specifically for debug
checks, but I'm doing this wholesale conversion first since we've
accumulated thousands of these already, and it's not immediately
obvious which ones are suitable for ASSERT.
