From 5d116372a8743c66de56dd2bd16dd395b112c369 Mon Sep 17 00:00:00 2001
From: Linus Groh <mail@linusgroh.de>
Date: Thu, 19 Aug 2021 08:44:09 +0100
Subject: [PATCH] LibJS: Implement Temporal.PlainMonthDay.prototype.toJSON()

---
 .../Temporal/PlainMonthDayPrototype.cpp       | 18 +++++++++++++++
 .../Runtime/Temporal/PlainMonthDayPrototype.h |  1 +
 .../PlainMonthDay.prototype.toJSON.js         | 23 +++++++++++++++++++
 3 files changed, 42 insertions(+)
 create mode 100644 Userland/Libraries/LibJS/Tests/builtins/Temporal/PlainMonthDay/PlainMonthDay.prototype.toJSON.js

diff --git a/Userland/Libraries/LibJS/Runtime/Temporal/PlainMonthDayPrototype.cpp b/Userland/Libraries/LibJS/Runtime/Temporal/PlainMonthDayPrototype.cpp
index 4ac2774571da18..0cc9bf35d664fd 100644
--- a/Userland/Libraries/LibJS/Runtime/Temporal/PlainMonthDayPrototype.cpp
+++ b/Userland/Libraries/LibJS/Runtime/Temporal/PlainMonthDayPrototype.cpp
@@ -35,6 +35,7 @@ void PlainMonthDayPrototype::initialize(GlobalObject& global_object)
     u8 attr = Attribute::Writable | Attribute::Configurable;
     define_native_function(vm.names.toString, to_string, 0, attr);
     define_native_function(vm.names.toLocaleString, to_locale_string, 0, attr);
+    define_native_function(vm.names.toJSON, to_json, 0, attr);
     define_native_function(vm.names.valueOf, value_of, 0, attr);
     define_native_function(vm.names.getISOFields, get_iso_fields, 0, attr);
 }
@@ -142,6 +143,23 @@ JS_DEFINE_NATIVE_FUNCTION(PlainMonthDayPrototype::to_locale_string)
     return js_string(vm, *string);
 }
 
+// 10.3.10 Temporal.PlainMonthDay.prototype.toJSON ( ), https://tc39.es/proposal-temporal/#sec-temporal.plainmonthday.prototype.tojson
+JS_DEFINE_NATIVE_FUNCTION(PlainMonthDayPrototype::to_json)
+{
+    // 1. Let monthDay be the this value.
+    // 2. Perform ? RequireInternalSlot(monthDay, [[InitializedTemporalMonthDay]]).
+    auto* month_day = typed_this(global_object);
+    if (vm.exception())
+        return {};
+
+    // 3. Return ? TemporalMonthDayToString(monthDay, "auto").
+    auto string = temporal_month_day_to_string(global_object, *month_day, "auto"sv);
+    if (vm.exception())
+        return {};
+
+    return js_string(vm, *string);
+}
+
 // 10.3.11 Temporal.PlainMonthDay.prototype.valueOf ( ), https://tc39.es/proposal-temporal/#sec-temporal.plainmonthday.prototype.valueof
 JS_DEFINE_NATIVE_FUNCTION(PlainMonthDayPrototype::value_of)
 {
diff --git a/Userland/Libraries/LibJS/Runtime/Temporal/PlainMonthDayPrototype.h b/Userland/Libraries/LibJS/Runtime/Temporal/PlainMonthDayPrototype.h
index e62aaf3f3771bd..7af50f88aea1db 100644
--- a/Userland/Libraries/LibJS/Runtime/Temporal/PlainMonthDayPrototype.h
+++ b/Userland/Libraries/LibJS/Runtime/Temporal/PlainMonthDayPrototype.h
@@ -24,6 +24,7 @@ class PlainMonthDayPrototype final : public Object {
     JS_DECLARE_NATIVE_FUNCTION(day_getter);
     JS_DECLARE_NATIVE_FUNCTION(to_string);
     JS_DECLARE_NATIVE_FUNCTION(to_locale_string);
+    JS_DECLARE_NATIVE_FUNCTION(to_json);
     JS_DECLARE_NATIVE_FUNCTION(value_of);
     JS_DECLARE_NATIVE_FUNCTION(get_iso_fields);
 };
diff --git a/Userland/Libraries/LibJS/Tests/builtins/Temporal/PlainMonthDay/PlainMonthDay.prototype.toJSON.js b/Userland/Libraries/LibJS/Tests/builtins/Temporal/PlainMonthDay/PlainMonthDay.prototype.toJSON.js
new file mode 100644
index 00000000000000..ea568c8fff7f99
--- /dev/null
+++ b/Userland/Libraries/LibJS/Tests/builtins/Temporal/PlainMonthDay/PlainMonthDay.prototype.toJSON.js
@@ -0,0 +1,23 @@
+describe("correct behavior", () => {
+    test("length is 0", () => {
+        expect(Temporal.PlainMonthDay.prototype.toJSON).toHaveLength(0);
+    });
+
+    test("basic functionality", () => {
+        let plainMonthDay;
+
+        plainMonthDay = new Temporal.PlainMonthDay(7, 6);
+        expect(plainMonthDay.toJSON()).toBe("07-06");
+
+        plainMonthDay = new Temporal.PlainMonthDay(7, 6, { toString: () => "foo" }, 2021);
+        expect(plainMonthDay.toJSON()).toBe("2021-07-06[u-ca=foo]");
+    });
+});
+
+describe("errors", () => {
+    test("this value must be a Temporal.PlainMonthDay object", () => {
+        expect(() => {
+            Temporal.PlainMonthDay.prototype.toJSON.call("foo");
+        }).toThrowWithMessage(TypeError, "Not a Temporal.PlainMonthDay");
+    });
+});