LibJS: Implement Intl %SegmentsPrototype%.containing

4 files changed, 79 insertions, 1 deletions

diff --git a/Userland/Libraries/LibJS/Runtime/CommonPropertyNames.h b/Userland/Libraries/LibJS/Runtime/CommonPropertyNames.h
index a261f00a63..9f0bd564b4 100644
--- a/Userland/Libraries/LibJS/Runtime/CommonPropertyNames.h
+++ b/Userland/Libraries/LibJS/Runtime/CommonPropertyNames.h
@@ -105,6 +105,7 @@ namespace JS {
     P(console)                               \
     P(construct)                             \
     P(constructor)                           \
+    P(containing)                            \
     P(compare)                               \
     P(copyWithin)                            \
     P(cos)                                   \
diff --git a/Userland/Libraries/LibJS/Runtime/Intl/SegmentsPrototype.cpp b/Userland/Libraries/LibJS/Runtime/Intl/SegmentsPrototype.cpp
index 6d5870ff7f..e48cdfb46e 100644
--- a/Userland/Libraries/LibJS/Runtime/Intl/SegmentsPrototype.cpp
+++ b/Userland/Libraries/LibJS/Runtime/Intl/SegmentsPrototype.cpp
@@ -4,9 +4,9 @@
  * SPDX-License-Identifier: BSD-2-Clause
  */
 
+#include <AK/Utf16View.h>
 #include <LibJS/Runtime/GlobalObject.h>
 #include <LibJS/Runtime/Intl/SegmentIterator.h>
-#include <LibJS/Runtime/Intl/Segments.h>
 #include <LibJS/Runtime/Intl/SegmentsPrototype.h>
 
 namespace JS::Intl {
@@ -25,6 +25,40 @@ void SegmentsPrototype::initialize(GlobalObject& global_object)
 
     u8 attr = Attribute::Writable | Attribute::Configurable;
     define_native_function(*vm.well_known_symbol_iterator(), symbol_iterator, 0, attr);
+    define_native_function(vm.names.containing, containing, 1, attr);
+}
+
+// 18.5.2.1 %SegmentsPrototype%.containing ( index ), https://tc39.es/ecma402/#sec-%segmentsprototype%.containing
+JS_DEFINE_NATIVE_FUNCTION(SegmentsPrototype::containing)
+{
+    // 1. Let segments be the this value.
+    // 2. Perform ? RequireInternalSlot(segments, [[SegmentsSegmenter]]).
+    auto* segments = TRY(typed_this_object(global_object));
+
+    // 3. Let segmenter be segments.[[SegmentsSegmenter]].
+    auto const& segmenter = segments->segments_segmenter();
+
+    // 4. Let string be segments.[[SegmentsString]].
+    auto string = segments->segments_string();
+
+    // 5. Let len be the length of string.
+    auto length = string.length_in_code_units();
+
+    // 6. Let n be ? ToIntegerOrInfinity(index).
+    auto n = TRY(vm.argument(0).to_integer_or_infinity(global_object));
+
+    // 7. If n < 0 or n ≥ len, return undefined.
+    if (n < 0 || n >= length)
+        return js_undefined();
+
+    // 8. Let startIndex be ! FindBoundary(segmenter, string, n, before).
+    auto start_index = find_boundary(segmenter, string, n, Direction::Before, segments->boundaries_cache());
+
+    // 9. Let endIndex be ! FindBoundary(segmenter, string, n, after).
+    auto end_index = find_boundary(segmenter, string, n, Direction::After, segments->boundaries_cache());
+
+    // 10. Return ! CreateSegmentDataObject(segmenter, string, startIndex, endIndex).
+    return create_segment_data_object(global_object, segmenter, string, start_index, end_index);
 }
 
 // 18.5.2.2 %SegmentsPrototype% [ @@iterator ] ( ), https://tc39.es/ecma402/#sec-%segmentsprototype%-@@iterator
diff --git a/Userland/Libraries/LibJS/Runtime/Intl/SegmentsPrototype.h b/Userland/Libraries/LibJS/Runtime/Intl/SegmentsPrototype.h
index 143a4870bb..f8f749a248 100644
--- a/Userland/Libraries/LibJS/Runtime/Intl/SegmentsPrototype.h
+++ b/Userland/Libraries/LibJS/Runtime/Intl/SegmentsPrototype.h
@@ -20,6 +20,7 @@ public:
     virtual ~SegmentsPrototype() override = default;
 
 private:
+    JS_DECLARE_NATIVE_FUNCTION(containing);
     JS_DECLARE_NATIVE_FUNCTION(symbol_iterator);
 };
 
diff --git a/Userland/Libraries/LibJS/Tests/builtins/Intl/Segmenter/Segmenter.prototype.segment.js b/Userland/Libraries/LibJS/Tests/builtins/Intl/Segmenter/Segmenter.prototype.segment.js
index 0369987c61..4c415c672b 100644
--- a/Userland/Libraries/LibJS/Tests/builtins/Intl/Segmenter/Segmenter.prototype.segment.js
+++ b/Userland/Libraries/LibJS/Tests/builtins/Intl/Segmenter/Segmenter.prototype.segment.js
@@ -10,6 +10,48 @@ describe("correct behavior", () => {
         );
     });
 
+    test("returns segments object with valid containing method", () => {
+        const string = "hello friends!";
+        const graphemeSegmenter = new Intl.Segmenter("en", { granularity: "grapheme" });
+        const graphemeSegments = graphemeSegmenter.segment(string);
+        const graphemeSegment0 = graphemeSegments.containing(0);
+        expect(graphemeSegment0.segment).toBe("h");
+        expect(graphemeSegment0.index).toBe(0);
+        expect(graphemeSegment0.input).toBe(string);
+        expect(graphemeSegment0.isWordLike).toBeUndefined();
+        const graphemeSegment5 = graphemeSegments.containing(5);
+        expect(graphemeSegment5.segment).toBe(" ");
+        expect(graphemeSegment5.index).toBe(5);
+        expect(graphemeSegment5.input).toBe(string);
+        expect(graphemeSegment5.isWordLike).toBeUndefined();
+
+        const wordSegmenter = new Intl.Segmenter("en", { granularity: "word" });
+        const wordSegments = wordSegmenter.segment(string);
+        const wordSegment0 = wordSegments.containing(0);
+        expect(wordSegment0.segment).toBe("hello");
+        expect(wordSegment0.index).toBe(0);
+        expect(wordSegment0.input).toBe(string);
+        // FIXME: expect(wordSegment0.isWordLike).toBeTrue();
+        const wordSegment5 = wordSegments.containing(5);
+        expect(wordSegment5.segment).toBe(" ");
+        expect(wordSegment5.index).toBe(5);
+        expect(wordSegment5.input).toBe(string);
+        expect(wordSegment5.isWordLike).toBeFalse();
+
+        const sentenceSegmenter = new Intl.Segmenter("en", { granularity: "sentence" });
+        const sentenceSegments = sentenceSegmenter.segment(string);
+        const sentenceSegment0 = sentenceSegments.containing(0);
+        expect(sentenceSegment0.segment).toBe(string);
+        expect(sentenceSegment0.index).toBe(0);
+        expect(sentenceSegment0.input).toBe(string);
+        expect(sentenceSegment0.isWordLike).toBeUndefined();
+        const sentenceSegment5 = sentenceSegments.containing(5);
+        expect(sentenceSegment5.segment).toBe(sentenceSegment0.segment);
+        expect(sentenceSegment5.index).toBe(sentenceSegment0.index);
+        expect(sentenceSegment5.input).toBe(sentenceSegment0.input);
+        expect(sentenceSegment5.isWordLike).toBe(sentenceSegment0.isWordLike);
+    });
+
     test("returns segments object segment iterator", () => {
         const segmenter = new Intl.Segmenter();
         const segments = segmenter.segment("hello friends!");