Everywhere: Hoist the Libraries folder to the top-level

Author: https://github.com/trflynn89
Commit: 93712b24bf
Pull-request: https://github.com/LadybirdBrowser/ladybird/pull/2256
Reviewed-by: https://github.com/sideshowbarker

Libraries/LibJS/Tests/builtins/Temporal/Now/Now.plainDateTimeISO.js

@@ -0,0 +1,99 @@
+describe("correct behavior", () => {
+    test("length is 0", () => {
+        expect(Temporal.Now.plainDateTimeISO).toHaveLength(0);
+    });
+
+    test("basic functionality", () => {
+        const plainDateTime = Temporal.Now.plainDateTimeISO();
+        expect(plainDateTime).toBeInstanceOf(Temporal.PlainDateTime);
+        expect(plainDateTime.calendar.id).toBe("iso8601");
+    });
+
+    const plainDateTimeToEpochSeconds = plainDateTime =>
+        (plainDateTime.year - 1970) * 31_556_952 +
+        plainDateTime.dayOfYear * 86_400 +
+        plainDateTime.hour * 3_600 +
+        plainDateTime.minute * 60 +
+        plainDateTime.second +
+        plainDateTime.millisecond / 1_000 +
+        plainDateTime.microsecond / 1_000_000 +
+        plainDateTime.nanosecond / 1_000_000_000;
+
+    let timeZoneTested = false;
+
+    // Note: We test both positive and negative timezones because one might cross a year boundary.
+    //       Since a year does not have a fixed amount of seconds because it can be a leap year,
+    //       we cannot have a correct constant for seconds per year which is always correct.
+    //       However, by assuming years are at least 2 days long we can simply try the positive
+    //       and negative timezones and skip one if we jump the year. To ensure at least one is
+    //       tested we have the timeZoneTested which is only set to true if one of the tests passed.
+
+    // FIXME: The custom time zone tests are disabled due to being flaky. See:
+    //        https://github.com/SerenityOS/serenity/issues/20806
+
+    test.skip("custom time zone (positive)", () => {
+        const timeZone = {
+            getOffsetNanosecondsFor() {
+                return 86399999999999;
+            },
+        };
+
+        const [plainDateTime, plainDateTimeWithOffset] = withinSameSecond(() => {
+            return [Temporal.Now.plainDateTimeISO("UTC"), Temporal.Now.plainDateTimeISO(timeZone)];
+        });
+
+        if (plainDateTime.year !== plainDateTimeWithOffset.year) return;
+
+        const differenceSeconds =
+            plainDateTimeToEpochSeconds(plainDateTimeWithOffset) -
+            plainDateTimeToEpochSeconds(plainDateTime);
+        expect(Math.floor(differenceSeconds)).toBe(86400);
+        timeZoneTested = true;
+    });
+
+    test.skip("custom time zone (negative)", () => {
+        const timeZone = {
+            getOffsetNanosecondsFor() {
+                return -86399999999999;
+            },
+        };
+
+        const [plainDateTime, plainDateTimeWithOffset] = withinSameSecond(() => {
+            return [Temporal.Now.plainDateTimeISO("UTC"), Temporal.Now.plainDateTimeISO(timeZone)];
+        });
+
+        if (plainDateTime.year !== plainDateTimeWithOffset.year) return;
+
+        const differenceSeconds =
+            plainDateTimeToEpochSeconds(plainDateTimeWithOffset) -
+            plainDateTimeToEpochSeconds(plainDateTime);
+        expect(Math.floor(differenceSeconds)).toBe(-86400);
+        timeZoneTested = true;
+    });
+
+    test.skip("custom time zone test was executed", () => {
+        expect(timeZoneTested).toBeTrue();
+    });
+
+    test("cannot have a time zone with more than a day", () => {
+        [86400000000000, -86400000000000, 86400000000001, 86400000000002].forEach(offset => {
+            const timeZone = {
+                getOffsetNanosecondsFor() {
+                    return offset;
+                },
+            };
+            expect(() => Temporal.Now.plainDateTimeISO(timeZone)).toThrowWithMessage(
+                RangeError,
+                "Invalid offset nanoseconds value, must be in range -86400 * 10^9 + 1 to 86400 * 10^9 - 1"
+            );
+        });
+    });
+});
+
+describe("errors", () => {
+    test("custom time zone doesn't have a getOffsetNanosecondsFor function", () => {
+        expect(() => {
+            Temporal.Now.plainDateTimeISO({});
+        }).toThrowWithMessage(TypeError, "getOffsetNanosecondsFor is undefined");
+    });
+});