Redesign Intl API and implement some services (#2478)

This Pull Request fixes/closes #1180. (I'll open a tracking issue for the progress)

It changes the following:

- Redesigns the internal API of Intl to (hopefully!) make it easier to implement a service.
- Implements the `Intl.Locale` service. 
- Implements the `Intl.Collator` service.
- Implements the `Intl.ListFormat` service.

On the subject of the failing tests. Some of them are caused by missing locale data in the `icu_testdata` crate; we would need to regenerate that with the missing locales, or vendor a custom default data.

On the other hand, there are some tests that are bugs from the ICU4X crate. The repo https://github.com/jedel1043/icu4x-test262 currently tracks the found bugs when running test262. I'll sync with the ICU4X team to try to fix those.

cc @sffc

Cargo.toml

@@ -12,6 +12,7 @@ members = [
     "boa_wasm",
     "boa_examples",
     "boa_macros",
+    "boa_icu_provider",
 ]
 
 [workspace.package]
@@ -32,6 +33,7 @@ boa_unicode = { version = "0.16.0", path = "boa_unicode" }
 boa_macros = { version = "0.16.0", path = "boa_macros" }
 boa_ast = { version = "0.16.0", path = "boa_ast" }
 boa_parser = { version = "0.16.0", path = "boa_parser" }
+boa_icu_provider = { version = "0.16.0", path = "boa_icu_provider" }
 
 [workspace.metadata.workspaces]
 allow_branch = "main"

boa_ast/src/lib.rs

@@ -1,7 +1,7 @@
-//! Boa's **boa_ast** crate implements an ECMAScript abstract syntax tree.
+//! Boa's **`boa_ast`** crate implements an ECMAScript abstract syntax tree.
 //!
 //! # Crate Overview
-//! **boa_ast** contains representations of [**Parse Nodes**][grammar] as defined by the ECMAScript
+//! **`boa_ast`** contains representations of [**Parse Nodes**][grammar] as defined by the ECMAScript
 //! spec. Some `Parse Node`s are not represented by Boa's AST, because a lot of grammar productions
 //! are only used to throw [**Early Errors**][early], and don't influence the evaluation of the AST
 //! itself.
@@ -17,13 +17,14 @@
 //! Try out the most recent release with Boa's live demo [playground][boa-playground].  
 //!
 //! # Boa Crates
-//!  - **boa_ast** - Boa's ECMAScript Abstract Syntax Tree.
-//!  - **boa_engine** - Boa's implementation of ECMAScript builtin objects and execution.
-//!  - **boa_gc** - Boa's garbage collector
-//!  - **boa_interner** - Boa's string interner
-//!  - **boa_parser** - Boa's lexer and parser
-//!  - **boa_profiler** - Boa's code profiler
-//!  - **boa_unicode** - Boa's Unicode identifier
+//!  - **`boa_ast`** - Boa's ECMAScript Abstract Syntax Tree.
+//!  - **`boa_engine`** - Boa's implementation of ECMAScript builtin objects and execution.
+//!  - **`boa_gc`** - Boa's garbage collector.
+//!  - **`boa_interner`** - Boa's string interner.
+//!  - **`boa_parser`** - Boa's lexer and parser.
+//!  - **`boa_profiler`** - Boa's code profiler.
+//!  - **`boa_unicode`** - Boa's Unicode identifier.
+//!  - **`boa_icu_provider`** - Boa's ICU4X data provider.
 //!
 //! [grammar]: https://tc39.es/ecma262/#sec-syntactic-grammar
 //! [early]: https://tc39.es/ecma262/#sec-static-semantic-rules

boa_cli/Cargo.toml

@@ -12,7 +12,7 @@ repository.workspace = true
 rust-version.workspace = true
 
 [dependencies]
-boa_engine = { workspace = true, features = ["deser", "console", "flowgraph"] }
+boa_engine = { workspace = true, features = ["deser", "console", "flowgraph", "intl"] }
 boa_ast = { workspace = true, features = ["serde"]}
 boa_parser.workspace = true
 rustyline = "10.0.0"

boa_engine/Cargo.toml

@@ -15,13 +15,18 @@ rust-version.workspace = true
 profiler = ["boa_profiler/profiler"]
 deser = ["boa_interner/serde", "boa_ast/serde"]
 intl = [
-    "dep:icu_locale_canonicalizer",
+    "dep:boa_icu_provider",
+    "dep:icu_locid_transform",
     "dep:icu_locid",
     "dep:icu_datetime",
     "dep:icu_plurals",
     "dep:icu_provider",
-    "dep:icu_testdata",
-    "dep:sys-locale"
+    "dep:icu_provider_adapters",
+    "dep:icu_calendar",
+    "dep:icu_collator",
+    "dep:icu_list",
+    "dep:writeable",
+    "dep:sys-locale",
 ]
 
 fuzz = ["boa_ast/fuzz", "boa_interner/fuzz"]
@@ -59,12 +64,19 @@ tap = "1.0.1"
 sptr = "0.3.2"
 static_assertions = "1.1.0"
 thiserror = "1.0.38"
-icu_locale_canonicalizer = { version = "0.6.0", features = ["serde"], optional = true }
-icu_locid = { version = "0.6.0", features = ["serde"], optional = true }
-icu_datetime = { version = "0.6.0", features = ["serde"], optional = true }
-icu_plurals = { version = "0.6.0", features = ["serde"], optional = true }
-icu_provider = { version = "0.6.0", optional = true }
-icu_testdata = { version = "0.6.0", optional = true }
+
+# intl deps
+boa_icu_provider = { workspace = true, optional = true }
+icu_locid_transform = { version = "1.0.0", features = ["serde"], optional = true }
+icu_locid = { version = "1.0.0", features = ["serde"], optional = true }
+icu_datetime = { version = "1.0.0", features = ["serde", "experimental"], optional = true }
+icu_calendar = { version = "1.0.0", optional = true }
+icu_collator = { version = "1.0.1", features = ["serde"], optional = true }
+icu_plurals = { version = "1.0.0", features = ["serde"], optional = true }
+icu_provider = { version = "1.0.1", optional = true }
+icu_provider_adapters = { version = "1.0.0", features = ["serde"], optional = true }
+icu_list = { version = "1.0.0", features = ["serde"], optional = true }
+writeable = { version = "0.5.0", optional = true }
 sys-locale = { version = "0.2.3", optional = true }
 
 [dev-dependencies]

boa_engine/src/builtins/array/mod.rs

@@ -13,6 +13,7 @@ pub mod array_iterator;
 #[cfg(test)]
 mod tests;
 
+use boa_macros::utf16;
 use boa_profiler::Profiler;
 use tap::{Conv, Pipe};
 
@@ -117,6 +118,7 @@ impl BuiltIn for Array {
         .method(Self::some, "some", 1)
         .method(Self::sort, "sort", 1)
         .method(Self::splice, "splice", 2)
+        .method(Self::to_locale_string, "toLocaleString", 0)
         .method(Self::reduce, "reduce", 1)
         .method(Self::reduce_right, "reduceRight", 1)
         .method(Self::keys, "keys", 0)
@@ -2027,6 +2029,72 @@ impl Array {
         Ok(a.into())
     }
 
+    /// [`Array.prototype.toLocaleString ( [ locales [ , options ] ] )`][spec].
+    ///
+    /// Returns a string representing the elements of the array. The elements are converted to
+    /// strings using their `toLocaleString` methods and these strings are separated by a
+    /// locale-specific string (such as a comma ",").
+    ///
+    /// More information:
+    ///  - [MDN documentation][mdn]
+    ///
+    /// [spec]: https://tc39.es/ecma402/#sup-array.prototype.tolocalestring
+    /// [mdn]: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/toLocaleString
+    pub(crate) fn to_locale_string(
+        this: &JsValue,
+        args: &[JsValue],
+        context: &mut Context,
+    ) -> JsResult<JsValue> {
+        // 1. Let array be ? ToObject(this value).
+        let array = this.to_object(context)?;
+        // 2. Let len be ? ToLength(? Get(array, "length")).
+        let len = array.length_of_array_like(context)?;
+
+        // 3. Let separator be the implementation-defined list-separator String value appropriate for the host environment's current locale (such as ", ").
+        let separator = {
+            #[cfg(feature = "intl")]
+            {
+                // TODO: this should eventually return a locale-sensitive separator.
+                utf16!(", ")
+            }
+
+            #[cfg(not(feature = "intl"))]
+            {
+                utf16!(", ")
+            }
+        };
+
+        // 4. Let R be the empty String.
+        let mut r = Vec::new();
+
+        // 5. Let k be 0.
+        // 6. Repeat, while k < len,
+        for k in 0..len {
+            // a. If k > 0, then
+            if k > 0 {
+                // i. Set R to the string-concatenation of R and separator.
+                r.extend_from_slice(separator);
+            }
+
+            // b. Let nextElement be ? Get(array, ! ToString(k)).
+            let next = array.get(k, context)?;
+
+            // c. If nextElement is not undefined or null, then
+            if !next.is_null_or_undefined() {
+                // i. Let S be ? ToString(? Invoke(nextElement, "toLocaleString", « locales, options »)).
+                let s = next
+                    .invoke("toLocaleString", args, context)?
+                    .to_string(context)?;
+
+                // ii. Set R to the string-concatenation of R and S.
+                r.extend_from_slice(&s);
+            }
+            //     d. Increase k by 1.
+        }
+        // 7. Return R.
+        Ok(js_string!(r).into())
+    }
+
     /// `Array.prototype.splice ( start, [deleteCount[, ...items]] )`
     ///
     /// Splices an array by following

boa_engine/src/builtins/console/mod.rs

@@ -52,19 +52,16 @@ fn logger(msg: LogMessage, console_state: &Console) {
 
 /// This represents the `console` formatter.
 pub fn formatter(data: &[JsValue], context: &mut Context) -> JsResult<String> {
-    let target = data
-        .get(0)
-        .cloned()
-        .unwrap_or_default()
-        .to_string(context)?;
-
-    match data.len() {
-        0 => Ok(String::new()),
-        1 => Ok(target.to_std_string_escaped()),
-        _ => {
+    match data {
+        [] => Ok(String::new()),
+        [val] => Ok(val.to_string(context)?.to_std_string_escaped()),
+        data => {
             let mut formatted = String::new();
             let mut arg_index = 1;
-            let target = target.to_std_string_escaped();
+            let target = data
+                .get_or_undefined(0)
+                .to_string(context)?
+                .to_std_string_escaped();
             let mut chars = target.chars();
             while let Some(c) = chars.next() {
                 if c == '%' {
@@ -94,9 +91,7 @@ pub fn formatter(data: &[JsValue], context: &mut Context) -> JsResult<String> {
                         /* string */
                         's' => {
                             let arg = data
-                                .get(arg_index)
-                                .cloned()
-                                .unwrap_or_default()
+                                .get_or_undefined(arg_index)
                                 .to_string(context)?
                                 .to_std_string_escaped();
                             formatted.push_str(&arg);