Partial implementation for Intl.DateTimeFormat (#2025)

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This Pull Request provides initial implementation for DateTimeFormat constructor. It relates to #1562.

It changes the following:

- Adds `Intl.DateTimeFormat` property
- Partially implements `DateTimeFormat` constructor (`InitializeDateTimeFormat` step is postponed).
- Introduces `ObjectData::DateTimeFormat`

boa_engine/src/builtins/intl/date_time_format.rs

@@ -0,0 +1,114 @@
+//! This module implements the global `Intl.DateTimeFormat` object.
+//!
+//! `Intl.DateTimeFormat` is a built-in object that has properties and methods for date and time i18n.
+//!
+//! More information:
+//!  - [ECMAScript reference][spec]
+//!
+//! [spec]: https://tc39.es/ecma402/#datetimeformat-objects
+
+use crate::{
+    context::intrinsics::StandardConstructors,
+    object::internal_methods::get_prototype_from_constructor,
+    object::{ConstructorBuilder, JsObject, ObjectData},
+    Context, JsResult, JsString, JsValue,
+};
+
+use boa_gc::{Finalize, Trace};
+use boa_profiler::Profiler;
+
+/// JavaScript `Intl.DateTimeFormat` object.
+#[derive(Debug, Clone, Trace, Finalize)]
+pub struct DateTimeFormat {
+    initialized_date_time_format: bool,
+    locale: JsString,
+    calendar: JsString,
+    numbering_system: JsString,
+    time_zone: JsString,
+    weekday: JsString,
+    era: JsString,
+    year: JsString,
+    month: JsString,
+    day: JsString,
+    day_period: JsString,
+    hour: JsString,
+    minute: JsString,
+    second: JsString,
+    fractional_second_digits: JsString,
+    time_zone_name: JsString,
+    hour_cycle: JsString,
+    pattern: JsString,
+    bound_format: JsString,
+}
+
+impl DateTimeFormat {
+    const NAME: &'static str = "DateTimeFormat";
+
+    pub(super) fn init(context: &mut Context) -> JsObject {
+        let _timer = Profiler::global().start_event(Self::NAME, "init");
+
+        ConstructorBuilder::new(context, Self::constructor)
+            .name(Self::NAME)
+            .length(0)
+            .build()
+    }
+}
+
+impl DateTimeFormat {
+    /// The `Intl.DateTimeFormat` constructor is the `%DateTimeFormat%` intrinsic object and a standard built-in property of the `Intl` object.
+    ///
+    /// More information:
+    ///  - [ECMAScript reference][spec]
+    ///  - [MDN documentation][mdn]
+    ///
+    /// [spec]: https://tc39.es/ecma402/#datetimeformat-objects
+    /// [mdn]: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Intl/DateTimeFormat
+    pub(crate) fn constructor(
+        new_target: &JsValue,
+        _args: &[JsValue],
+        context: &mut Context,
+    ) -> JsResult<JsValue> {
+        // 1. If NewTarget is undefined, let newTarget be the active function object, else let newTarget be NewTarget.
+        let prototype = get_prototype_from_constructor(
+            new_target,
+            StandardConstructors::date_time_format,
+            context,
+        )?;
+        // 2. Let dateTimeFormat be ? OrdinaryCreateFromConstructor(newTarget, "%DateTimeFormat.prototype%",
+        // « [[InitializedDateTimeFormat]], [[Locale]], [[Calendar]], [[NumberingSystem]], [[TimeZone]], [[Weekday]],
+        // [[Era]], [[Year]], [[Month]], [[Day]], [[DayPeriod]], [[Hour]], [[Minute]], [[Second]],
+        // [[FractionalSecondDigits]], [[TimeZoneName]], [[HourCycle]], [[Pattern]], [[BoundFormat]] »).
+        let date_time_format = JsObject::from_proto_and_data(
+            prototype,
+            ObjectData::date_time_format(Box::new(Self {
+                initialized_date_time_format: true,
+                locale: JsString::from("en-US"),
+                calendar: JsString::from("gregory"),
+                numbering_system: JsString::from("arab"),
+                time_zone: JsString::from("UTC"),
+                weekday: JsString::from("narrow"),
+                era: JsString::from("narrow"),
+                year: JsString::from("numeric"),
+                month: JsString::from("narrow"),
+                day: JsString::from("numeric"),
+                day_period: JsString::from("narrow"),
+                hour: JsString::from("numeric"),
+                minute: JsString::from("numeric"),
+                second: JsString::from("numeric"),
+                fractional_second_digits: JsString::from(""),
+                time_zone_name: JsString::from(""),
+                hour_cycle: JsString::from("h24"),
+                pattern: JsString::from("{hour}:{minute}"),
+                bound_format: JsString::from("undefined"),
+            })),
+        );
+
+        // TODO 3. Perform ? InitializeDateTimeFormat(dateTimeFormat, locales, options).
+        // TODO 4. If the implementation supports the normative optional constructor mode of 4.3 Note 1, then
+        // TODO a. Let this be the this value.
+        // TODO b. Return ? ChainDateTimeFormat(dateTimeFormat, NewTarget, this).
+
+        // 5. Return dateTimeFormat.
+        Ok(JsValue::Object(date_time_format))
+    }
+}

boa_engine/src/builtins/intl/mod.rs

@@ -8,12 +8,16 @@
 //! [spec]: https://tc39.es/ecma402/#intl-object
 
 use crate::{
+    builtins::intl::date_time_format::DateTimeFormat,
     builtins::{Array, BuiltIn, JsArgs},
     object::ObjectInitializer,
     property::Attribute,
     symbol::WellKnownSymbols,
     Context, JsResult, JsString, JsValue,
 };
+
+pub mod date_time_format;
+
 use boa_profiler::Profiler;
 use indexmap::IndexSet;
 use tap::{Conv, Pipe};
@@ -29,13 +33,19 @@ impl BuiltIn for Intl {
         let _timer = Profiler::global().start_event(Self::NAME, "init");
 
         let string_tag = WellKnownSymbols::to_string_tag();
+        let date_time_format = DateTimeFormat::init(context);
         ObjectInitializer::new(context)
             .function(Self::get_canonical_locales, "getCanonicalLocales", 1)
             .property(
                 string_tag,
                 Self::NAME,
                 Attribute::READONLY | Attribute::NON_ENUMERABLE | Attribute::CONFIGURABLE,
             )
+            .property(
+                "DateTimeFormat",
+                date_time_format,
+                Attribute::WRITABLE | Attribute::NON_ENUMERABLE | Attribute::CONFIGURABLE,
+            )
             .build()
             .conv::<JsValue>()
             .pipe(Some)

boa_engine/src/context/intrinsics.rs

@@ -109,6 +109,7 @@ pub struct StandardConstructors {
     array_buffer: StandardConstructor,
     data_view: StandardConstructor,
     promise: StandardConstructor,
+    date_time_format: StandardConstructor,
 }
 
 impl Default for StandardConstructors {
@@ -163,6 +164,7 @@ impl Default for StandardConstructors {
             array_buffer: StandardConstructor::default(),
             data_view: StandardConstructor::default(),
             promise: StandardConstructor::default(),
+            date_time_format: StandardConstructor::default(),
         };
 
         // The value of `Array.prototype` is the Array prototype object.
@@ -365,6 +367,11 @@ impl StandardConstructors {
     pub fn promise(&self) -> &StandardConstructor {
         &self.promise
     }
+
+    #[inline]
+    pub fn date_time_format(&self) -> &StandardConstructor {
+        &self.date_time_format
+    }
 }
 
 /// Cached intrinsic objects

boa_engine/src/object/mod.rs

@@ -29,6 +29,7 @@ use crate::{
             arguments::ParameterMap, BoundFunction, Captures, Function, NativeFunctionSignature,
         },
         generator::Generator,
+        intl::date_time_format::DateTimeFormat,
         map::map_iterator::MapIterator,
         map::ordered_map::OrderedMap,
         object::for_in_iterator::ForInIterator,
@@ -164,6 +165,7 @@ pub enum ObjectKind {
     NativeObject(Box<dyn NativeObject>),
     IntegerIndexed(IntegerIndexed),
     Promise(Promise),
+    DateTimeFormat(Box<DateTimeFormat>),
 }
 
 impl ObjectData {
@@ -428,6 +430,14 @@ impl ObjectData {
             internal_methods: &INTEGER_INDEXED_EXOTIC_INTERNAL_METHODS,
         }
     }
+
+    /// Create the `DateTimeFormat` object data
+    pub fn date_time_format(date_time_fmt: Box<DateTimeFormat>) -> Self {
+        Self {
+            kind: ObjectKind::DateTimeFormat(date_time_fmt),
+            internal_methods: &ORDINARY_INTERNAL_METHODS,
+        }
+    }
 }
 
 impl Display for ObjectKind {
@@ -463,6 +473,7 @@ impl Display for ObjectKind {
             Self::IntegerIndexed(_) => "TypedArray",
             Self::DataView(_) => "DataView",
             Self::Promise(_) => "Promise",
+            Self::DateTimeFormat(_) => "DateTimeFormat",
         })
     }
 }