LibJS: Implement Intl.DurationFormat.prototype.format

Userland/Libraries/LibJS/Runtime/Intl/DurationFormatPrototype.cpp

@@ -25,9 +25,36 @@ void DurationFormatPrototype::initialize(GlobalObject& global_object)
     define_direct_property(*vm.well_known_symbol_to_string_tag(), js_string(vm, "Intl.DurationFormat"), Attribute::Configurable);
 
     u8 attr = Attribute::Writable | Attribute::Configurable;
+    define_native_function(vm.names.format, format, 1, attr);
     define_native_function(vm.names.resolvedOptions, resolved_options, 0, attr);
 }
 
+// 1.4.3 Intl.DurationFormat.prototype.format ( duration ), https://tc39.es/proposal-intl-duration-format/#sec-Intl.DurationFormat.prototype.format
+JS_DEFINE_NATIVE_FUNCTION(DurationFormatPrototype::format)
+{
+    // 1. Let df be this value.
+    // 2. Perform ? RequireInternalSlot(df, [[InitializedDurationFormat]]).
+    auto* duration_format = TRY(typed_this_object(global_object));
+
+    // 3. Let record be ? ToDurationRecord(duration).
+    auto record = TRY(to_duration_record(global_object, vm.argument(0)));
+
+    // 4. Let formatted be ? PartitionDurationFormatPattern(df, record).
+    auto formatted = TRY(partition_duration_format_pattern(global_object, *duration_format, record));
+
+    // 5. Let result be a new empty String.
+    StringBuilder result;
+
+    // 6. For each element part in formatted, in List order, do
+    for (auto const& part : formatted) {
+        // a. Set result to the string-concatenation of result and part.[[Value]].
+        result.append(part.value);
+    }
+
+    // 7. Return result.
+    return js_string(vm, result.build());
+}
+
 // 1.4.5 Intl.DurationFormat.prototype.resolvedOptions ( ), https://tc39.es/proposal-intl-duration-format/#sec-Intl.DurationFormat.prototype.resolvedOptions
 JS_DEFINE_NATIVE_FUNCTION(DurationFormatPrototype::resolved_options)
 {

Userland/Libraries/LibJS/Runtime/Intl/DurationFormatPrototype.h

@@ -20,6 +20,7 @@ public:
     virtual ~DurationFormatPrototype() override = default;
 
 private:
+    JS_DECLARE_NATIVE_FUNCTION(format);
     JS_DECLARE_NATIVE_FUNCTION(resolved_options);
 };
 

Userland/Libraries/LibJS/Tests/builtins/Intl/DurationFormat/DurationFormat.prototype.format.js

@@ -0,0 +1,65 @@
+describe("correct behavior", () => {
+    test("length is 1", () => {
+        expect(Intl.DurationFormat.prototype.format).toHaveLength(1);
+    });
+
+    test("formats duration correctly", () => {
+        const duration = {
+            years: 1,
+            months: 2,
+            weeks: 3,
+            days: 3,
+            hours: 4,
+            minutes: 5,
+            seconds: 6,
+            milliseconds: 7,
+            microseconds: 8,
+            nanoseconds: 9,
+        };
+        expect(new Intl.DurationFormat().format(duration)).toBe(
+            "1 year, 2 months, 3 weeks, 3 days, 4 hours, 5 minutes, 6 seconds, 7 milliseconds, 8 microseconds, and 9 nanoseconds"
+        );
+        expect(new Intl.DurationFormat("en").format(duration)).toBe(
+            "1 year, 2 months, 3 weeks, 3 days, 4 hours, 5 minutes, 6 seconds, 7 milliseconds, 8 microseconds, and 9 nanoseconds"
+        );
+        expect(new Intl.DurationFormat("en", { style: "long" }).format(duration)).toBe(
+            "1 year, 2 months, 3 weeks, 3 days, 4 hours, 5 minutes, 6 seconds, 7 milliseconds, 8 microseconds, and 9 nanoseconds"
+        );
+        expect(new Intl.DurationFormat("en", { style: "short" }).format(duration)).toBe(
+            "1 yr, 2 mths, 3 wks, 3 days, 4 hr, 5 min, 6 sec, 7 ms, 8 μs, and 9 ns"
+        );
+        expect(new Intl.DurationFormat("en", { style: "narrow" }).format(duration)).toBe(
+            "1y, 2m, 3w, 3d, 4h, 5m, 6s, 7ms, 8μs, and 9ns"
+        );
+        expect(new Intl.DurationFormat("en", { style: "digital" }).format(duration)).toBe(
+            "1y, 2m, 3w, 3d, and 4:05:06.007"
+        );
+        expect(
+            new Intl.DurationFormat("en", {
+                style: "narrow",
+                nanoseconds: "numeric",
+                fractionalDigits: 7,
+            }).format(duration)
+        ).toBe("1y, 2m, 3w, 3d, 4h, 5m, 6s, 7ms, and 8.009μs");
+
+        expect(new Intl.DurationFormat("de", { style: "long" }).format(duration)).toBe(
+            "1 Jahr, 2 Monate, 3 Wochen, 3 Tage, 4 Stunden, 5 Minuten, 6 Sekunden, 7 Millisekunden, 8 Mikrosekunden und 9 Nanosekunden"
+        );
+        expect(new Intl.DurationFormat("de", { style: "short" }).format(duration)).toBe(
+            "1 J, 2 Mon., 3 Wo., 3 Tg., 4 Std., 5 Min., 6 Sek., 7 ms, 8 μs und 9 ns"
+        );
+        expect(new Intl.DurationFormat("de", { style: "narrow" }).format(duration)).toBe(
+            "1 J, 2 M, 3 W, 3 T, 4 Std., 5 Min., 6 Sek., 7 ms, 8 μs und 9 ns"
+        );
+        expect(new Intl.DurationFormat("de", { style: "digital" }).format(duration)).toBe(
+            "1 J, 2 M, 3 W, 3 T und 4:05:06,007"
+        );
+        expect(
+            new Intl.DurationFormat("de", {
+                style: "narrow",
+                nanoseconds: "numeric",
+                fractionalDigits: 7,
+            }).format(duration)
+        ).toBe("1 J, 2 M, 3 W, 3 T, 4 Std., 5 Min., 6 Sek., 7 ms und 8,009 μs");
+    });
+});