LibJS: Convert TimeZone AOs to ThrowCompletionOr

12 files changed, 99 insertions, 195 deletions

diff --git a/Userland/Libraries/LibJS/Runtime/Temporal/Instant.cpp b/Userland/Libraries/LibJS/Runtime/Temporal/Instant.cpp
index 46ed524bbd..7e194666fd 100644
--- a/Userland/Libraries/LibJS/Runtime/Temporal/Instant.cpp
+++ b/Userland/Libraries/LibJS/Runtime/Temporal/Instant.cpp
@@ -135,9 +135,7 @@ BigInt* parse_temporal_instant(GlobalObject& global_object, String const& iso_st
     }
 
     // 7. Let offsetNanoseconds be ? ParseTimeZoneOffsetString(offsetString).
-    auto offset_nanoseconds = parse_time_zone_offset_string(global_object, *offset_string);
-    if (vm.exception())
-        return {};
+    auto offset_nanoseconds = TRY_OR_DISCARD(parse_time_zone_offset_string(global_object, *offset_string));
 
     // 8. Return utc − offsetNanoseconds.
     return js_bigint(vm, utc->big_integer().minus(Crypto::SignedBigInteger::create_from(offset_nanoseconds)));
@@ -256,20 +254,16 @@ Optional<String> temporal_instant_to_string(GlobalObject& global_object, Instant
 
     // 4. If outputTimeZone is undefined, then
     if (output_time_zone.is_undefined()) {
-        // a. Set outputTimeZone to ? CreateTemporalTimeZone("UTC").
-        output_time_zone = create_temporal_time_zone(global_object, "UTC"sv);
         // TODO: Can this really throw...?
-        if (vm.exception())
-            return {};
+        // a. Set outputTimeZone to ? CreateTemporalTimeZone("UTC").
+        output_time_zone = TRY_OR_DISCARD(create_temporal_time_zone(global_object, "UTC"sv));
     }
 
     // 5. Let isoCalendar be ! GetISO8601Calendar().
     auto* iso_calendar = get_iso8601_calendar(global_object);
 
     // 6. Let dateTime be ? BuiltinTimeZoneGetPlainDateTimeFor(outputTimeZone, instant, isoCalendar).
-    auto* date_time = builtin_time_zone_get_plain_date_time_for(global_object, output_time_zone, instant, *iso_calendar);
-    if (vm.exception())
-        return {};
+    auto* date_time = TRY_OR_DISCARD(builtin_time_zone_get_plain_date_time_for(global_object, output_time_zone, instant, *iso_calendar));
 
     // 7. Let dateTimeString be ? TemporalDateTimeToString(dateTime.[[ISOYear]], dateTime.[[ISOMonth]], dateTime.[[ISODay]], dateTime.[[ISOHour]], dateTime.[[ISOMinute]], dateTime.[[ISOSecond]], dateTime.[[ISOMillisecond]], dateTime.[[ISOMicrosecond]], dateTime.[[ISONanosecond]], undefined, precision, "never").
     auto date_time_string = temporal_date_time_to_string(global_object, date_time->iso_year(), date_time->iso_month(), date_time->iso_day(), date_time->iso_hour(), date_time->iso_minute(), date_time->iso_second(), date_time->iso_millisecond(), date_time->iso_microsecond(), date_time->iso_nanosecond(), js_undefined(), precision, "never"sv);
@@ -286,9 +280,7 @@ Optional<String> temporal_instant_to_string(GlobalObject& global_object, Instant
     // 9. Else,
     else {
         // a. Let timeZoneString be ? BuiltinTimeZoneGetOffsetStringFor(timeZone, instant).
-        time_zone_string = builtin_time_zone_get_offset_string_for(global_object, time_zone, instant);
-        if (vm.exception())
-            return {};
+        time_zone_string = TRY_OR_DISCARD(builtin_time_zone_get_offset_string_for(global_object, time_zone, instant));
     }
 
     // 10. Return the string-concatenation of dateTimeString and timeZoneString.
diff --git a/Userland/Libraries/LibJS/Runtime/Temporal/InstantPrototype.cpp b/Userland/Libraries/LibJS/Runtime/Temporal/InstantPrototype.cpp
index ed96c10be9..449dce9ed2 100644
--- a/Userland/Libraries/LibJS/Runtime/Temporal/InstantPrototype.cpp
+++ b/Userland/Libraries/LibJS/Runtime/Temporal/InstantPrototype.cpp
@@ -426,9 +426,7 @@ JS_DEFINE_NATIVE_FUNCTION(InstantPrototype::to_string)
     // 5. If timeZone is not undefined, then
     if (!time_zone.is_undefined()) {
         // a. Set timeZone to ? ToTemporalTimeZone(timeZone).
-        time_zone = to_temporal_time_zone(global_object, time_zone);
-        if (vm.exception())
-            return {};
+        time_zone = TRY_OR_DISCARD(to_temporal_time_zone(global_object, time_zone));
     }
 
     // 6. Let precision be ? ToSecondsStringPrecision(options).
@@ -548,9 +546,7 @@ JS_DEFINE_NATIVE_FUNCTION(InstantPrototype::to_zoned_date_time)
     }
 
     // 9. Let timeZone be ? ToTemporalTimeZone(temporalTimeZoneLike).
-    auto* time_zone = to_temporal_time_zone(global_object, temporal_time_zone_like);
-    if (vm.exception())
-        return {};
+    auto* time_zone = TRY_OR_DISCARD(to_temporal_time_zone(global_object, temporal_time_zone_like));
 
     // 10. Return ? CreateTemporalZonedDateTime(instant.[[Nanoseconds]], timeZone, calendar).
     return TRY_OR_DISCARD(create_temporal_zoned_date_time(global_object, instant->nanoseconds(), *time_zone, *calendar));
@@ -582,9 +578,7 @@ JS_DEFINE_NATIVE_FUNCTION(InstantPrototype::to_zoned_date_time_iso)
     }
 
     // 4. Let timeZone be ? ToTemporalTimeZone(item).
-    auto* time_zone = to_temporal_time_zone(global_object, item);
-    if (vm.exception())
-        return {};
+    auto* time_zone = TRY_OR_DISCARD(to_temporal_time_zone(global_object, item));
 
     // 5. Let calendar be ! GetISO8601Calendar().
     auto* calendar = get_iso8601_calendar(global_object);
diff --git a/Userland/Libraries/LibJS/Runtime/Temporal/Now.cpp b/Userland/Libraries/LibJS/Runtime/Temporal/Now.cpp
index 3a732631a5..5d86a882ff 100644
--- a/Userland/Libraries/LibJS/Runtime/Temporal/Now.cpp
+++ b/Userland/Libraries/LibJS/Runtime/Temporal/Now.cpp
@@ -159,7 +159,7 @@ TimeZone* system_time_zone(GlobalObject& global_object)
     auto identifier = default_time_zone();
 
     // 2. Return ! CreateTemporalTimeZone(identifier).
-    return create_temporal_time_zone(global_object, identifier);
+    return TRY_OR_DISCARD(create_temporal_time_zone(global_object, identifier));
 }
 
 // 2.3.2 SystemUTCEpochNanoseconds ( ), https://tc39.es/proposal-temporal/#sec-temporal-systemutcepochnanoseconds
@@ -209,9 +209,7 @@ PlainDateTime* system_date_time(GlobalObject& global_object, Value temporal_time
     // 2. Else,
     else {
         // a. Let timeZone be ? ToTemporalTimeZone(temporalTimeZoneLike).
-        time_zone = to_temporal_time_zone(global_object, temporal_time_zone_like);
-        if (vm.exception())
-            return {};
+        time_zone = TRY_OR_DISCARD(to_temporal_time_zone(global_object, temporal_time_zone_like));
     }
 
     // 3. Let calendar be ? ToTemporalCalendar(calendarLike).
@@ -223,7 +221,7 @@ PlainDateTime* system_date_time(GlobalObject& global_object, Value temporal_time
     auto* instant = system_instant(global_object);
 
     // 5. Return ? BuiltinTimeZoneGetPlainDateTimeFor(timeZone, instant, calendar).
-    return builtin_time_zone_get_plain_date_time_for(global_object, time_zone, *instant, *calendar);
+    return TRY_OR_DISCARD(builtin_time_zone_get_plain_date_time_for(global_object, time_zone, *instant, *calendar));
 }
 
 // 2.3.5 SystemZonedDateTime ( temporalTimeZoneLike, calendarLike ), https://tc39.es/proposal-temporal/#sec-temporal-systemzoneddatetime
@@ -240,9 +238,7 @@ ZonedDateTime* system_zoned_date_time(GlobalObject& global_object, Value tempora
     // 2. Else,
     else {
         // a. Let timeZone be ? ToTemporalTimeZone(temporalTimeZoneLike).
-        time_zone = to_temporal_time_zone(global_object, temporal_time_zone_like);
-        if (vm.exception())
-            return {};
+        time_zone = TRY_OR_DISCARD(to_temporal_time_zone(global_object, temporal_time_zone_like));
     }
 
     // 3. Let calendar be ? ToTemporalCalendar(calendarLike).
diff --git a/Userland/Libraries/LibJS/Runtime/Temporal/PlainDate.cpp b/Userland/Libraries/LibJS/Runtime/Temporal/PlainDate.cpp
index 5482e2880a..b9365fd39a 100644
--- a/Userland/Libraries/LibJS/Runtime/Temporal/PlainDate.cpp
+++ b/Userland/Libraries/LibJS/Runtime/Temporal/PlainDate.cpp
@@ -98,9 +98,7 @@ PlainDate* to_temporal_date(GlobalObject& global_object, Value item, Object* opt
             auto* instant = create_temporal_instant(global_object, zoned_date_time.nanoseconds());
 
             // ii. Let plainDateTime be ? BuiltinTimeZoneGetPlainDateTimeFor(item.[[TimeZone]], instant, item.[[Calendar]]).
-            auto* plain_date_time = builtin_time_zone_get_plain_date_time_for(global_object, &zoned_date_time.time_zone(), *instant, zoned_date_time.calendar());
-            if (vm.exception())
-                return {};
+            auto* plain_date_time = TRY_OR_DISCARD(builtin_time_zone_get_plain_date_time_for(global_object, &zoned_date_time.time_zone(), *instant, zoned_date_time.calendar()));
 
             // iii. Return ! CreateTemporalDate(plainDateTime.[[ISOYear]], plainDateTime.[[ISOMonth]], plainDateTime.[[ISODay]], plainDateTime.[[Calendar]]).
             return create_temporal_date(global_object, plain_date_time->iso_year(), plain_date_time->iso_month(), plain_date_time->iso_day(), plain_date_time->calendar());
diff --git a/Userland/Libraries/LibJS/Runtime/Temporal/PlainDateTime.cpp b/Userland/Libraries/LibJS/Runtime/Temporal/PlainDateTime.cpp
index 8abc504921..7adb749702 100644
--- a/Userland/Libraries/LibJS/Runtime/Temporal/PlainDateTime.cpp
+++ b/Userland/Libraries/LibJS/Runtime/Temporal/PlainDateTime.cpp
@@ -167,7 +167,7 @@ PlainDateTime* to_temporal_date_time(GlobalObject& global_object, Value item, Ob
             auto* instant = create_temporal_instant(global_object, zoned_date_time.nanoseconds());
 
             // ii. Return ? BuiltinTimeZoneGetPlainDateTimeFor(item.[[TimeZone]], instant, item.[[Calendar]]).
-            return builtin_time_zone_get_plain_date_time_for(global_object, &zoned_date_time.time_zone(), *instant, zoned_date_time.calendar());
+            return TRY_OR_DISCARD(builtin_time_zone_get_plain_date_time_for(global_object, &zoned_date_time.time_zone(), *instant, zoned_date_time.calendar()));
         }
 
         // c. If item has an [[InitializedTemporalDate]] internal slot, then
diff --git a/Userland/Libraries/LibJS/Runtime/Temporal/PlainTime.cpp b/Userland/Libraries/LibJS/Runtime/Temporal/PlainTime.cpp
index bd51cc1f72..023c15882e 100644
--- a/Userland/Libraries/LibJS/Runtime/Temporal/PlainTime.cpp
+++ b/Userland/Libraries/LibJS/Runtime/Temporal/PlainTime.cpp
@@ -68,9 +68,7 @@ PlainTime* to_temporal_time(GlobalObject& global_object, Value item, Optional<St
             // i. Let instant be ! CreateTemporalInstant(item.[[Nanoseconds]]).
             auto* instant = create_temporal_instant(global_object, zoned_date_time.nanoseconds());
             // ii. Set plainDateTime to ? BuiltinTimeZoneGetPlainDateTimeFor(item.[[TimeZone]], instant, item.[[Calendar]]).
-            auto* plain_date_time = builtin_time_zone_get_plain_date_time_for(global_object, &zoned_date_time.time_zone(), *instant, zoned_date_time.calendar());
-            if (vm.exception())
-                return {};
+            auto* plain_date_time = TRY_OR_DISCARD(builtin_time_zone_get_plain_date_time_for(global_object, &zoned_date_time.time_zone(), *instant, zoned_date_time.calendar()));
             // iii. Return ! CreateTemporalTime(plainDateTime.[[ISOHour]], plainDateTime.[[ISOMinute]], plainDateTime.[[ISOSecond]], plainDateTime.[[ISOMillisecond]], plainDateTime.[[ISOMicrosecond]], plainDateTime.[[ISONanosecond]]).
             return create_temporal_time(global_object, plain_date_time->iso_hour(), plain_date_time->iso_minute(), plain_date_time->iso_second(), plain_date_time->iso_millisecond(), plain_date_time->iso_microsecond(), plain_date_time->iso_nanosecond());
         }
diff --git a/Userland/Libraries/LibJS/Runtime/Temporal/TimeZone.cpp b/Userland/Libraries/LibJS/Runtime/Temporal/TimeZone.cpp
index 34a4f0ca9a..45255ef4c1 100644
--- a/Userland/Libraries/LibJS/Runtime/Temporal/TimeZone.cpp
+++ b/Userland/Libraries/LibJS/Runtime/Temporal/TimeZone.cpp
@@ -66,7 +66,7 @@ String default_time_zone()
 }
 
 // 11.6.1 ParseTemporalTimeZone ( string ), https://tc39.es/proposal-temporal/#sec-temporal-parsetemporaltimezone
-String parse_temporal_time_zone(GlobalObject& global_object, String const& string)
+ThrowCompletionOr<String> parse_temporal_time_zone(GlobalObject& global_object, String const& string)
 {
     auto& vm = global_object.vm();
 
@@ -74,19 +74,19 @@ String parse_temporal_time_zone(GlobalObject& global_object, String const& strin
 
     // 2. Let result be ? ParseTemporalTimeZoneString(string).
     auto result = parse_temporal_time_zone_string(global_object, string);
-    if (vm.exception())
-        return {};
+    if (auto* exception = vm.exception())
+        return throw_completion(exception->value());
 
     // 3. If result.[[Z]] is not undefined, return "UTC".
     if (result->z)
-        return "UTC";
+        return String { "UTC" };
 
     // 4. Return result.[[Name]].
     return *result->name;
 }
 
 // 11.6.2 CreateTemporalTimeZone ( identifier [ , newTarget ] ), https://tc39.es/proposal-temporal/#sec-temporal-createtemporaltimezone
-TimeZone* create_temporal_time_zone(GlobalObject& global_object, String const& identifier, FunctionObject const* new_target)
+ThrowCompletionOr<TimeZone*> create_temporal_time_zone(GlobalObject& global_object, String const& identifier, FunctionObject const* new_target)
 {
     // 1. If newTarget is not present, set it to %Temporal.TimeZone%.
     if (!new_target)
@@ -94,12 +94,12 @@ TimeZone* create_temporal_time_zone(GlobalObject& global_object, String const& i
 
     // 2. Let object be ? OrdinaryCreateFromConstructor(newTarget, "%Temporal.TimeZone.prototype%", « [[InitializedTemporalTimeZone]], [[Identifier]], [[OffsetNanoseconds]] »).
     // 3. Set object.[[Identifier]] to identifier.
-    auto* object = TRY_OR_DISCARD(ordinary_create_from_constructor<TimeZone>(global_object, *new_target, &GlobalObject::temporal_time_zone_prototype, identifier));
+    auto* object = TRY(ordinary_create_from_constructor<TimeZone>(global_object, *new_target, &GlobalObject::temporal_time_zone_prototype, identifier));
 
     // 4. If identifier satisfies the syntax of a TimeZoneNumericUTCOffset (see 13.33), then
     if (is_valid_time_zone_numeric_utc_offset_syntax(identifier)) {
         // a. Set object.[[OffsetNanoseconds]] to ! ParseTimeZoneOffsetString(identifier).
-        object->set_offset_nanoseconds(parse_time_zone_offset_string(global_object, identifier));
+        object->set_offset_nanoseconds(TRY(parse_time_zone_offset_string(global_object, identifier)));
     }
     // 5. Else,
     else {
@@ -207,7 +207,7 @@ bool is_valid_time_zone_numeric_utc_offset_syntax(String const& offset_string)
 }
 
 // 11.6.8 ParseTimeZoneOffsetString ( offsetString ), https://tc39.es/proposal-temporal/#sec-temporal-parsetimezoneoffsetstring
-double parse_time_zone_offset_string(GlobalObject& global_object, String const& offset_string)
+ThrowCompletionOr<double> parse_time_zone_offset_string(GlobalObject& global_object, String const& offset_string)
 {
     auto& vm = global_object.vm();
 
@@ -222,10 +222,8 @@ double parse_time_zone_offset_string(GlobalObject& global_object, String const&
     Optional<StringView> seconds_part;
     Optional<StringView> fraction_part;
     auto success = parse_time_zone_numeric_utc_offset_syntax(offset_string, sign_part, hours_part, minutes_part, seconds_part, fraction_part);
-    if (!success) {
-        vm.throw_exception<RangeError>(global_object, ErrorType::InvalidFormat, "TimeZone offset");
-        return {};
-    }
+    if (!success)
+        return vm.throw_completion<RangeError>(global_object, ErrorType::InvalidFormat, "TimeZone offset");
 
     // 4. If either hours or sign are undefined, throw a RangeError exception.
     // NOTE: Both of these checks are always false, due to the handling of Step 2
@@ -317,7 +315,7 @@ String format_time_zone_offset_string(double offset_nanoseconds)
 }
 
 // 11.6.10 ToTemporalTimeZone ( temporalTimeZoneLike ), https://tc39.es/proposal-temporal/#sec-temporal-totemporaltimezone
-Object* to_temporal_time_zone(GlobalObject& global_object, Value temporal_time_zone_like)
+ThrowCompletionOr<Object*> to_temporal_time_zone(GlobalObject& global_object, Value temporal_time_zone_like)
 {
     auto& vm = global_object.vm();
 
@@ -333,21 +331,21 @@ Object* to_temporal_time_zone(GlobalObject& global_object, Value temporal_time_z
 
         // b. If ? HasProperty(temporalTimeZoneLike, "timeZone") is false, return temporalTimeZoneLike.
         auto has_property = temporal_time_zone_like.as_object().has_property(vm.names.timeZone);
-        if (vm.exception())
-            return {};
+        if (auto* exception = vm.exception())
+            return throw_completion(exception->value());
         if (!has_property)
             return &temporal_time_zone_like.as_object();
 
         // c. Set temporalTimeZoneLike to ? Get(temporalTimeZoneLike, "timeZone").
         temporal_time_zone_like = temporal_time_zone_like.as_object().get(vm.names.timeZone);
-        if (vm.exception())
-            return {};
+        if (auto* exception = vm.exception())
+            return throw_completion(exception->value());
 
         // d. If Type(temporalTimeZoneLike) is Object and ? HasProperty(temporalTimeZoneLike, "timeZone") is false, return temporalTimeZoneLike.
         if (temporal_time_zone_like.is_object()) {
             has_property = temporal_time_zone_like.as_object().has_property(vm.names.timeZone);
-            if (vm.exception())
-                return {};
+            if (auto* exception = vm.exception())
+                return throw_completion(exception->value());
             if (!has_property)
                 return &temporal_time_zone_like.as_object();
         }
@@ -355,27 +353,25 @@ Object* to_temporal_time_zone(GlobalObject& global_object, Value temporal_time_z
 
     // 2. Let identifier be ? ToString(temporalTimeZoneLike).
     auto identifier = temporal_time_zone_like.to_string(global_object);
-    if (vm.exception())
-        return {};
+    if (auto* exception = vm.exception())
+        return throw_completion(exception->value());
 
     // 3. Let result be ? ParseTemporalTimeZone(identifier).
-    auto result = parse_temporal_time_zone(global_object, identifier);
-    if (vm.exception())
-        return {};
+    auto result = TRY(parse_temporal_time_zone(global_object, identifier));
 
     // 4. Return ? CreateTemporalTimeZone(result).
-    return create_temporal_time_zone(global_object, result);
+    return TRY(create_temporal_time_zone(global_object, result));
 }
 
 // 11.6.11 GetOffsetNanosecondsFor ( timeZone, instant ), https://tc39.es/proposal-temporal/#sec-temporal-getoffsetnanosecondsfor
-double get_offset_nanoseconds_for(GlobalObject& global_object, Value time_zone, Instant& instant)
+ThrowCompletionOr<double> get_offset_nanoseconds_for(GlobalObject& global_object, Value time_zone, Instant& instant)
 {
     auto& vm = global_object.vm();
 
     // 1. Let getOffsetNanosecondsFor be ? GetMethod(timeZone, "getOffsetNanosecondsFor").
     auto* get_offset_nanoseconds_for = time_zone.get_method(global_object, vm.names.getOffsetNanosecondsFor);
-    if (vm.exception())
-        return {};
+    if (auto* exception = vm.exception())
+        return throw_completion(exception->value());
 
     // 2. If getOffsetNanosecondsFor is undefined, set getOffsetNanosecondsFor to %Temporal.TimeZone.prototype.getOffsetNanosecondsFor%.
     if (!get_offset_nanoseconds_for)
@@ -383,57 +379,45 @@ double get_offset_nanoseconds_for(GlobalObject& global_object, Value time_zone,
 
     // 3. Let offsetNanoseconds be ? Call(getOffsetNanosecondsFor, timeZone, « instant »).
     auto offset_nanoseconds_value = vm.call(*get_offset_nanoseconds_for, time_zone, &instant);
-    if (vm.exception())
-        return {};
+    if (auto* exception = vm.exception())
+        return throw_completion(exception->value());
 
     // 4. If Type(offsetNanoseconds) is not Number, throw a TypeError exception.
-    if (!offset_nanoseconds_value.is_number()) {
-        vm.throw_exception<TypeError>(global_object, ErrorType::IsNotA, "Offset nanoseconds value", "number");
-        return {};
-    }
+    if (!offset_nanoseconds_value.is_number())
+        return vm.throw_completion<TypeError>(global_object, ErrorType::IsNotA, "Offset nanoseconds value", "number");
 
     // 5. If ! IsIntegralNumber(offsetNanoseconds) is false, throw a RangeError exception.
-    if (!offset_nanoseconds_value.is_integral_number()) {
-        vm.throw_exception<RangeError>(global_object, ErrorType::IsNotAn, "Offset nanoseconds value", "integral number");
-        return {};
-    }
+    if (!offset_nanoseconds_value.is_integral_number())
+        return vm.throw_completion<RangeError>(global_object, ErrorType::IsNotAn, "Offset nanoseconds value", "integral number");
 
     // 6. Set offsetNanoseconds to ℝ(offsetNanoseconds).
     auto offset_nanoseconds = offset_nanoseconds_value.as_double();
 
     // 7. If abs(offsetNanoseconds) > 86400 × 10^9, throw a RangeError exception.
-    if (fabs(offset_nanoseconds) > 86400000000000.0) {
-        vm.throw_exception<RangeError>(global_object, ErrorType::TemporalInvalidOffsetNanosecondsValue);
-        return {};
-    }
+    if (fabs(offset_nanoseconds) > 86400000000000.0)
+        return vm.throw_completion<RangeError>(global_object, ErrorType::TemporalInvalidOffsetNanosecondsValue);
 
     // 8. Return offsetNanoseconds.
     return offset_nanoseconds;
 }
 
 // 11.6.12 BuiltinTimeZoneGetOffsetStringFor ( timeZone, instant ), https://tc39.es/proposal-temporal/#sec-temporal-builtintimezonegetoffsetstringfor
-Optional<String> builtin_time_zone_get_offset_string_for(GlobalObject& global_object, Value time_zone, Instant& instant)
+ThrowCompletionOr<String> builtin_time_zone_get_offset_string_for(GlobalObject& global_object, Value time_zone, Instant& instant)
 {
-    auto& vm = global_object.vm();
-
     // 1. Let offsetNanoseconds be ? GetOffsetNanosecondsFor(timeZone, instant).
-    auto offset_nanoseconds = get_offset_nanoseconds_for(global_object, time_zone, instant);
-    if (vm.exception())
-        return {};
+    auto offset_nanoseconds = TRY(get_offset_nanoseconds_for(global_object, time_zone, instant));
 
     // 2. Return ! FormatTimeZoneOffsetString(offsetNanoseconds).
     return format_time_zone_offset_string(offset_nanoseconds);
 }
 
 // 11.6.13 BuiltinTimeZoneGetPlainDateTimeFor ( timeZone, instant, calendar ), https://tc39.es/proposal-temporal/#sec-temporal-builtintimezonegetplaindatetimefor
-PlainDateTime* builtin_time_zone_get_plain_date_time_for(GlobalObject& global_object, Value time_zone, Instant& instant, Object& calendar)
+ThrowCompletionOr<PlainDateTime*> builtin_time_zone_get_plain_date_time_for(GlobalObject& global_object, Value time_zone, Instant& instant, Object& calendar)
 {
     auto& vm = global_object.vm();
 
     // 1. Let offsetNanoseconds be ? GetOffsetNanosecondsFor(timeZone, instant).
-    auto offset_nanoseconds = get_offset_nanoseconds_for(global_object, time_zone, instant);
-    if (vm.exception())
-        return {};
+    auto offset_nanoseconds = TRY(get_offset_nanoseconds_for(global_object, time_zone, instant));
 
     // 2. Let result be ! GetISOPartsFromEpoch(instant.[[Nanoseconds]]).
     auto result = get_iso_parts_from_epoch(instant.nanoseconds());
@@ -442,7 +426,10 @@ PlainDateTime* builtin_time_zone_get_plain_date_time_for(GlobalObject& global_ob
     result = balance_iso_date_time(result.year, result.month, result.day, result.hour, result.minute, result.second, result.millisecond, result.microsecond, result.nanosecond + offset_nanoseconds);
 
     // 4. Return ? CreateTemporalDateTime(result.[[Year]], result.[[Month]], result.[[Day]], result.[[Hour]], result.[[Minute]], result.[[Second]], result.[[Millisecond]], result.[[Microsecond]], result.[[Nanosecond]], calendar).
-    return create_temporal_date_time(global_object, result.year, result.month, result.day, result.hour, result.minute, result.second, result.millisecond, result.microsecond, result.nanosecond, calendar);
+    auto* date_time = create_temporal_date_time(global_object, result.year, result.month, result.day, result.hour, result.minute, result.second, result.millisecond, result.microsecond, result.nanosecond, calendar);
+    if (auto* exception = vm.exception())
+        return throw_completion(exception->value());
+    return date_time;
 }
 
 }
diff --git a/Userland/Libraries/LibJS/Runtime/Temporal/TimeZone.h b/Userland/Libraries/LibJS/Runtime/Temporal/TimeZone.h
index 1e4d3e3051..8923d7fc93 100644
--- a/Userland/Libraries/LibJS/Runtime/Temporal/TimeZone.h
+++ b/Userland/Libraries/LibJS/Runtime/Temporal/TimeZone.h
@@ -35,16 +35,16 @@ private:
 bool is_valid_time_zone_name(String const& time_zone);
 String canonicalize_time_zone_name(String const& time_zone);
 String default_time_zone();
-String parse_temporal_time_zone(GlobalObject&, String const&);
-TimeZone* create_temporal_time_zone(GlobalObject&, String const& identifier, FunctionObject const* new_target = nullptr);
+ThrowCompletionOr<String> parse_temporal_time_zone(GlobalObject&, String const&);
+ThrowCompletionOr<TimeZone*> create_temporal_time_zone(GlobalObject&, String const& identifier, FunctionObject const* new_target = nullptr);
 ISODateTime get_iso_parts_from_epoch(BigInt const& epoch_nanoseconds);
 i64 get_iana_time_zone_offset_nanoseconds(BigInt const& epoch_nanoseconds, String const& time_zone_identifier);
-double parse_time_zone_offset_string(GlobalObject&, String const&);
+ThrowCompletionOr<double> parse_time_zone_offset_string(GlobalObject&, String const&);
 String format_time_zone_offset_string(double offset_nanoseconds);
-Object* to_temporal_time_zone(GlobalObject&, Value temporal_time_zone_like);
-double get_offset_nanoseconds_for(GlobalObject&, Value time_zone, Instant&);
-Optional<String> builtin_time_zone_get_offset_string_for(GlobalObject&, Value time_zone, Instant&);
-PlainDateTime* builtin_time_zone_get_plain_date_time_for(GlobalObject&, Value time_zone, Instant&, Object& calendar);
+ThrowCompletionOr<Object*> to_temporal_time_zone(GlobalObject&, Value temporal_time_zone_like);
+ThrowCompletionOr<double> get_offset_nanoseconds_for(GlobalObject&, Value time_zone, Instant&);
+ThrowCompletionOr<String> builtin_time_zone_get_offset_string_for(GlobalObject&, Value time_zone, Instant&);
+ThrowCompletionOr<PlainDateTime*> builtin_time_zone_get_plain_date_time_for(GlobalObject&, Value time_zone, Instant&, Object& calendar);
 
 bool is_valid_time_zone_numeric_utc_offset_syntax(String const&);
 
diff --git a/Userland/Libraries/LibJS/Runtime/Temporal/TimeZoneConstructor.cpp b/Userland/Libraries/LibJS/Runtime/Temporal/TimeZoneConstructor.cpp
index ac5a8c7065..0767be28fd 100644
--- a/Userland/Libraries/LibJS/Runtime/Temporal/TimeZoneConstructor.cpp
+++ b/Userland/Libraries/LibJS/Runtime/Temporal/TimeZoneConstructor.cpp
@@ -58,9 +58,7 @@ Value TimeZoneConstructor::construct(FunctionObject& new_target)
     // 3. If identifier satisfies the syntax of a TimeZoneNumericUTCOffset (see 13.33), then
     if (is_valid_time_zone_numeric_utc_offset_syntax(identifier)) {
         // a. Let offsetNanoseconds be ? ParseTimeZoneOffsetString(identifier).
-        auto offset_nanoseconds = parse_time_zone_offset_string(global_object, identifier);
-        if (vm.exception())
-            return {};
+        auto offset_nanoseconds = TRY_OR_DISCARD(parse_time_zone_offset_string(global_object, identifier));
 
         // b. Let canonical be ! FormatTimeZoneOffsetString(offsetNanoseconds).
         canonical = format_time_zone_offset_string(offset_nanoseconds);
@@ -79,7 +77,7 @@ Value TimeZoneConstructor::construct(FunctionObject& new_target)
     }
 
     // 5. Return ? CreateTemporalTimeZone(canonical, NewTarget).
-    return create_temporal_time_zone(global_object, canonical, &new_target);
+    return TRY_OR_DISCARD(create_temporal_time_zone(global_object, canonical, &new_target));
 }
 
 // 11.3.2 Temporal.TimeZone.from ( item ), https://tc39.es/proposal-temporal/#sec-temporal.timezone.from
@@ -88,7 +86,7 @@ JS_DEFINE_NATIVE_FUNCTION(TimeZoneConstructor::from)
     auto item = vm.argument(0);
 
     // 1. Return ? ToTemporalTimeZone(item).
-    return to_temporal_time_zone(global_object, item);
+    return TRY_OR_DISCARD(to_temporal_time_zone(global_object, item));
 }
 
 }
diff --git a/Userland/Libraries/LibJS/Runtime/Temporal/TimeZonePrototype.cpp b/Userland/Libraries/LibJS/Runtime/Temporal/TimeZonePrototype.cpp
index 60e7b26edb..a1ea6c2046 100644
--- a/Userland/Libraries/LibJS/Runtime/Temporal/TimeZonePrototype.cpp
+++ b/Userland/Libraries/LibJS/Runtime/Temporal/TimeZonePrototype.cpp
@@ -85,10 +85,8 @@ JS_DEFINE_NATIVE_FUNCTION(TimeZonePrototype::get_offset_string_for)
         return {};
 
     // 4. Return ? BuiltinTimeZoneGetOffsetStringFor(timeZone, instant).
-    auto offset_string = builtin_time_zone_get_offset_string_for(global_object, time_zone, *instant);
-    if (vm.exception())
-        return {};
-    return js_string(vm, move(*offset_string));
+    auto offset_string = TRY_OR_DISCARD(builtin_time_zone_get_offset_string_for(global_object, time_zone, *instant));
+    return js_string(vm, move(offset_string));
 }
 
 // 11.4.6 Temporal.TimeZone.prototype.getPlainDateTimeFor ( instant [ , calendarLike ] ), https://tc39.es/proposal-temporal/#sec-temporal.timezone.prototype.getplaindatetimefor
@@ -108,7 +106,7 @@ JS_DEFINE_NATIVE_FUNCTION(TimeZonePrototype::get_plain_date_time_for)
         return {};
 
     // 4. Return ? BuiltinTimeZoneGetPlainDateTimeFor(timeZone, instant, calendar).
-    return builtin_time_zone_get_plain_date_time_for(global_object, time_zone, *instant, *calendar);
+    return TRY_OR_DISCARD(builtin_time_zone_get_plain_date_time_for(global_object, time_zone, *instant, *calendar));
 }
 
 // 11.4.11 Temporal.TimeZone.prototype.toString ( ), https://tc39.es/proposal-temporal/#sec-temporal.timezone.prototype.tostring
diff --git a/Userland/Libraries/LibJS/Runtime/Temporal/ZonedDateTimeConstructor.cpp b/Userland/Libraries/LibJS/Runtime/Temporal/ZonedDateTimeConstructor.cpp
index d9ca18db8a..6ae094c632 100644
--- a/Userland/Libraries/LibJS/Runtime/Temporal/ZonedDateTimeConstructor.cpp
+++ b/Userland/Libraries/LibJS/Runtime/Temporal/ZonedDateTimeConstructor.cpp
@@ -60,9 +60,7 @@ Value ZonedDateTimeConstructor::construct(FunctionObject& new_target)
     }
 
     // 4. Let timeZone be ? ToTemporalTimeZone(timeZoneLike).
-    auto* time_zone = to_temporal_time_zone(global_object, vm.argument(1));
-    if (vm.exception())
-        return {};
+    auto* time_zone = TRY_OR_DISCARD(to_temporal_time_zone(global_object, vm.argument(1)));
 
     // 5. Let calendar be ? ToTemporalCalendarWithISODefault(calendarLike).
     auto* calendar = to_temporal_calendar_with_iso_default(global_object, vm.argument(2));
diff --git a/Userland/Libraries/LibJS/Runtime/Temporal/ZonedDateTimePrototype.cpp b/Userland/Libraries/LibJS/Runtime/Temporal/ZonedDateTimePrototype.cpp
index e30d6118d4..43f7535d6c 100644
--- a/Userland/Libraries/LibJS/Runtime/Temporal/ZonedDateTimePrototype.cpp
+++ b/Userland/Libraries/LibJS/Runtime/Temporal/ZonedDateTimePrototype.cpp
@@ -118,9 +118,7 @@ JS_DEFINE_NATIVE_FUNCTION(ZonedDateTimePrototype::year_getter)
     auto& calendar = zoned_date_time->calendar();
 
     // 6. Let temporalDateTime be ? BuiltinTimeZoneGetPlainDateTimeFor(timeZone, instant, calendar).
-    auto* temporal_date_time = builtin_time_zone_get_plain_date_time_for(global_object, &time_zone, *instant, calendar);
-    if (vm.exception())
-        return {};
+    auto* temporal_date_time = TRY_OR_DISCARD(builtin_time_zone_get_plain_date_time_for(global_object, &time_zone, *instant, calendar));
 
     // 7. Return ? CalendarYear(calendar, temporalDateTime).
     return Value(calendar_year(global_object, calendar, *temporal_date_time));
@@ -145,9 +143,7 @@ JS_DEFINE_NATIVE_FUNCTION(ZonedDateTimePrototype::month_getter)
     auto& calendar = zoned_date_time->calendar();
 
     // 6. Let temporalDateTime be ? BuiltinTimeZoneGetPlainDateTimeFor(timeZone, instant, calendar).
-    auto* temporal_date_time = builtin_time_zone_get_plain_date_time_for(global_object, &time_zone, *instant, calendar);
-    if (vm.exception())
-        return {};
+    auto* temporal_date_time = TRY_OR_DISCARD(builtin_time_zone_get_plain_date_time_for(global_object, &time_zone, *instant, calendar));
 
     // 7. Return ? CalendarMonth(calendar, temporalDateTime).
     return Value(calendar_month(global_object, calendar, *temporal_date_time));
@@ -172,9 +168,7 @@ JS_DEFINE_NATIVE_FUNCTION(ZonedDateTimePrototype::month_code_getter)
     auto& calendar = zoned_date_time->calendar();
 
     // 6. Let temporalDateTime be ? BuiltinTimeZoneGetPlainDateTimeFor(timeZone, instant, calendar).
-    auto* temporal_date_time = builtin_time_zone_get_plain_date_time_for(global_object, &time_zone, *instant, calendar);
-    if (vm.exception())
-        return {};
+    auto* temporal_date_time = TRY_OR_DISCARD(builtin_time_zone_get_plain_date_time_for(global_object, &time_zone, *instant, calendar));
 
     // 7. Return ? CalendarMonthCode(calendar, temporalDateTime).
     return js_string(vm, calendar_month_code(global_object, calendar, *temporal_date_time));
@@ -199,9 +193,7 @@ JS_DEFINE_NATIVE_FUNCTION(ZonedDateTimePrototype::day_getter)
     auto& calendar = zoned_date_time->calendar();
 
     // 6. Let temporalDateTime be ? BuiltinTimeZoneGetPlainDateTimeFor(timeZone, instant, calendar).
-    auto* temporal_date_time = builtin_time_zone_get_plain_date_time_for(global_object, &time_zone, *instant, calendar);
-    if (vm.exception())
-        return {};
+    auto* temporal_date_time = TRY_OR_DISCARD(builtin_time_zone_get_plain_date_time_for(global_object, &time_zone, *instant, calendar));
 
     // 7. Return ? CalendarDay(calendar, temporalDateTime).
     return Value(calendar_day(global_object, calendar, *temporal_date_time));
@@ -226,9 +218,7 @@ JS_DEFINE_NATIVE_FUNCTION(ZonedDateTimePrototype::hour_getter)
     auto& calendar = zoned_date_time->calendar();
 
     // 6. Let temporalDateTime be ? BuiltinTimeZoneGetPlainDateTimeFor(timeZone, instant, calendar).
-    auto* temporal_date_time = builtin_time_zone_get_plain_date_time_for(global_object, &time_zone, *instant, calendar);
-    if (vm.exception())
-        return {};
+    auto* temporal_date_time = TRY_OR_DISCARD(builtin_time_zone_get_plain_date_time_for(global_object, &time_zone, *instant, calendar));
 
     // 7. Return 𝔽(temporalDateTime.[[ISOHour]]).
     return Value(temporal_date_time->iso_hour());
@@ -253,9 +243,7 @@ JS_DEFINE_NATIVE_FUNCTION(ZonedDateTimePrototype::minute_getter)
     auto& calendar = zoned_date_time->calendar();
 
     // 6. Let temporalDateTime be ? BuiltinTimeZoneGetPlainDateTimeFor(timeZone, instant, calendar).
-    auto* temporal_date_time = builtin_time_zone_get_plain_date_time_for(global_object, &time_zone, *instant, calendar);
-    if (vm.exception())
-        return {};
+    auto* temporal_date_time = TRY_OR_DISCARD(builtin_time_zone_get_plain_date_time_for(global_object, &time_zone, *instant, calendar));
 
     // 7. Return 𝔽(temporalDateTime.[[ISOMinute]]).
     return Value(temporal_date_time->iso_minute());
@@ -280,9 +268,7 @@ JS_DEFINE_NATIVE_FUNCTION(ZonedDateTimePrototype::second_getter)
     auto& calendar = zoned_date_time->calendar();
 
     // 6. Let temporalDateTime be ? BuiltinTimeZoneGetPlainDateTimeFor(timeZone, instant, calendar).
-    auto* temporal_date_time = builtin_time_zone_get_plain_date_time_for(global_object, &time_zone, *instant, calendar);
-    if (vm.exception())
-        return {};
+    auto* temporal_date_time = TRY_OR_DISCARD(builtin_time_zone_get_plain_date_time_for(global_object, &time_zone, *instant, calendar));
 
     // 7. Return 𝔽(temporalDateTime.[[ISOSecond]]).
     return Value(temporal_date_time->iso_second());
@@ -307,9 +293,7 @@ JS_DEFINE_NATIVE_FUNCTION(ZonedDateTimePrototype::millisecond_getter)
     auto& calendar = zoned_date_time->calendar();
 
     // 6. Let temporalDateTime be ? BuiltinTimeZoneGetPlainDateTimeFor(timeZone, instant, calendar).
-    auto* temporal_date_time = builtin_time_zone_get_plain_date_time_for(global_object, &time_zone, *instant, calendar);
-    if (vm.exception())
-        return {};
+    auto* temporal_date_time = TRY_OR_DISCARD(builtin_time_zone_get_plain_date_time_for(global_object, &time_zone, *instant, calendar));
 
     // 7. Return 𝔽(temporalDateTime.[[ISOMillisecond]]).
     return Value(temporal_date_time->iso_millisecond());
@@ -334,9 +318,7 @@ JS_DEFINE_NATIVE_FUNCTION(ZonedDateTimePrototype::microsecond_getter)
     auto& calendar = zoned_date_time->calendar();
 
     // 6. Let temporalDateTime be ? BuiltinTimeZoneGetPlainDateTimeFor(timeZone, instant, calendar).
-    auto* temporal_date_time = builtin_time_zone_get_plain_date_time_for(global_object, &time_zone, *instant, calendar);
-    if (vm.exception())
-        return {};
+    auto* temporal_date_time = TRY_OR_DISCARD(builtin_time_zone_get_plain_date_time_for(global_object, &time_zone, *instant, calendar));
 
     // 7. Return 𝔽(temporalDateTime.[[ISOMicrosecond]]).
     return Value(temporal_date_time->iso_microsecond());
@@ -361,9 +343,7 @@ JS_DEFINE_NATIVE_FUNCTION(ZonedDateTimePrototype::nanosecond_getter)
     auto& calendar = zoned_date_time->calendar();
 
     // 6. Let temporalDateTime be ? BuiltinTimeZoneGetPlainDateTimeFor(timeZone, instant, calendar).
-    auto* temporal_date_time = builtin_time_zone_get_plain_date_time_for(global_object, &time_zone, *instant, calendar);
-    if (vm.exception())
-        return {};
+    auto* temporal_date_time = TRY_OR_DISCARD(builtin_time_zone_get_plain_date_time_for(global_object, &time_zone, *instant, calendar));
 
     // 7. Return 𝔽(temporalDateTime.[[ISONanosecond]]).
     return Value(temporal_date_time->iso_nanosecond());
@@ -458,9 +438,7 @@ JS_DEFINE_NATIVE_FUNCTION(ZonedDateTimePrototype::day_of_week_getter)
     auto& calendar = zoned_date_time->calendar();
 
     // 6. Let temporalDateTime be ? BuiltinTimeZoneGetPlainDateTimeFor(timeZone, instant, calendar).
-    auto* temporal_date_time = builtin_time_zone_get_plain_date_time_for(global_object, &time_zone, *instant, calendar);
-    if (vm.exception())
-        return {};
+    auto* temporal_date_time = TRY_OR_DISCARD(builtin_time_zone_get_plain_date_time_for(global_object, &time_zone, *instant, calendar));
 
     // 7. Return ? CalendarDayOfWeek(calendar, temporalDateTime).
     return calendar_day_of_week(global_object, calendar, *temporal_date_time);
@@ -485,9 +463,7 @@ JS_DEFINE_NATIVE_FUNCTION(ZonedDateTimePrototype::day_of_year_getter)
     auto& calendar = zoned_date_time->calendar();
 
     // 6. Let temporalDateTime be ? BuiltinTimeZoneGetPlainDateTimeFor(timeZone, instant, calendar).
-    auto* temporal_date_time = builtin_time_zone_get_plain_date_time_for(global_object, &time_zone, *instant, calendar);
-    if (vm.exception())
-        return {};
+    auto* temporal_date_time = TRY_OR_DISCARD(builtin_time_zone_get_plain_date_time_for(global_object, &time_zone, *instant, calendar));
 
     // 7. Return ? CalendarDayOfYear(calendar, temporalDateTime).
     return calendar_day_of_year(global_object, calendar, *temporal_date_time);
@@ -512,9 +488,7 @@ JS_DEFINE_NATIVE_FUNCTION(ZonedDateTimePrototype::week_of_year_getter)
     auto& calendar = zoned_date_time->calendar();
 
     // 6. Let temporalDateTime be ? BuiltinTimeZoneGetPlainDateTimeFor(timeZone, instant, calendar).
-    auto* temporal_date_time = builtin_time_zone_get_plain_date_time_for(global_object, &time_zone, *instant, calendar);
-    if (vm.exception())
-        return {};
+    auto* temporal_date_time = TRY_OR_DISCARD(builtin_time_zone_get_plain_date_time_for(global_object, &time_zone, *instant, calendar));
 
     // 7. Return ? CalendarWeekOfYear(calendar, temporalDateTime).
     return calendar_week_of_year(global_object, calendar, *temporal_date_time);
@@ -539,9 +513,7 @@ JS_DEFINE_NATIVE_FUNCTION(ZonedDateTimePrototype::days_in_week_getter)
     auto& calendar = zoned_date_time->calendar();
 
     // 6. Let temporalDateTime be ? BuiltinTimeZoneGetPlainDateTimeFor(timeZone, instant, calendar).
-    auto* temporal_date_time = builtin_time_zone_get_plain_date_time_for(global_object, &time_zone, *instant, calendar);
-    if (vm.exception())
-        return {};
+    auto* temporal_date_time = TRY_OR_DISCARD(builtin_time_zone_get_plain_date_time_for(global_object, &time_zone, *instant, calendar));
 
     // 7. Return ? CalendarDaysInWeek(calendar, temporalDateTime).
     return calendar_days_in_week(global_object, calendar, *temporal_date_time);
@@ -566,9 +538,7 @@ JS_DEFINE_NATIVE_FUNCTION(ZonedDateTimePrototype::days_in_month_getter)
     auto& calendar = zoned_date_time->calendar();
 
     // 6. Let temporalDateTime be ? BuiltinTimeZoneGetPlainDateTimeFor(timeZone, instant, calendar).
-    auto* temporal_date_time = builtin_time_zone_get_plain_date_time_for(global_object, &time_zone, *instant, calendar);
-    if (vm.exception())
-        return {};
+    auto* temporal_date_time = TRY_OR_DISCARD(builtin_time_zone_get_plain_date_time_for(global_object, &time_zone, *instant, calendar));
 
     // 7. Return ? CalendarDaysInMonth(calendar, temporalDateTime).
     return calendar_days_in_month(global_object, calendar, *temporal_date_time);
@@ -593,9 +563,7 @@ JS_DEFINE_NATIVE_FUNCTION(ZonedDateTimePrototype::days_in_year_getter)
     auto& calendar = zoned_date_time->calendar();
 
     // 6. Let temporalDateTime be ? BuiltinTimeZoneGetPlainDateTimeFor(timeZone, instant, calendar).
-    auto* temporal_date_time = builtin_time_zone_get_plain_date_time_for(global_object, &time_zone, *instant, calendar);
-    if (vm.exception())
-        return {};
+    auto* temporal_date_time = TRY_OR_DISCARD(builtin_time_zone_get_plain_date_time_for(global_object, &time_zone, *instant, calendar));
 
     // 7. Return ? CalendarDaysInYear(calendar, temporalDateTime).
     return calendar_days_in_year(global_object, calendar, *temporal_date_time);
@@ -620,9 +588,7 @@ JS_DEFINE_NATIVE_FUNCTION(ZonedDateTimePrototype::months_in_year_getter)
     auto& calendar = zoned_date_time->calendar();
 
     // 6. Let temporalDateTime be ? BuiltinTimeZoneGetPlainDateTimeFor(timeZone, instant, calendar).
-    auto* temporal_date_time = builtin_time_zone_get_plain_date_time_for(global_object, &time_zone, *instant, calendar);
-    if (vm.exception())
-        return {};
+    auto* temporal_date_time = TRY_OR_DISCARD(builtin_time_zone_get_plain_date_time_for(global_object, &time_zone, *instant, calendar));
 
     // 7. Return ? CalendarMonthsInYear(calendar, temporalDateTime).
     return calendar_months_in_year(global_object, calendar, *temporal_date_time);
@@ -647,9 +613,7 @@ JS_DEFINE_NATIVE_FUNCTION(ZonedDateTimePrototype::in_leap_year_getter)
     auto& calendar = zoned_date_time->calendar();
 
     // 6. Let temporalDateTime be ? BuiltinTimeZoneGetPlainDateTimeFor(timeZone, instant, calendar).
-    auto* temporal_date_time = builtin_time_zone_get_plain_date_time_for(global_object, &time_zone, *instant, calendar);
-    if (vm.exception())
-        return {};
+    auto* temporal_date_time = TRY_OR_DISCARD(builtin_time_zone_get_plain_date_time_for(global_object, &time_zone, *instant, calendar));
 
     // 7. Return ? CalendarInLeapYear(calendar, temporalDateTime).
     return calendar_in_leap_year(global_object, calendar, *temporal_date_time);
@@ -671,7 +635,7 @@ JS_DEFINE_NATIVE_FUNCTION(ZonedDateTimePrototype::offset_nanoseconds_getter)
     auto* instant = create_temporal_instant(global_object, zoned_date_time->nanoseconds());
 
     // 5. Return 𝔽(? GetOffsetNanosecondsFor(timeZone, instant)).
-    return Value(get_offset_nanoseconds_for(global_object, &time_zone, *instant));
+    return Value(TRY_OR_DISCARD(get_offset_nanoseconds_for(global_object, &time_zone, *instant)));
 }
 
 // 6.3.29 get Temporal.ZonedDateTime.prototype.offset, https://tc39.es/proposal-temporal/#sec-get-temporal.zoneddatetime.prototype.offset
@@ -687,10 +651,8 @@ JS_DEFINE_NATIVE_FUNCTION(ZonedDateTimePrototype::offset_getter)
     auto* instant = create_temporal_instant(global_object, zoned_date_time->nanoseconds());
 
     // 4. Return ? BuiltinTimeZoneGetOffsetStringFor(zonedDateTime.[[TimeZone]], instant).
-    auto offset_string = builtin_time_zone_get_offset_string_for(global_object, &zoned_date_time->time_zone(), *instant);
-    if (vm.exception())
-        return {};
-    return js_string(vm, move(*offset_string));
+    auto offset_string = TRY_OR_DISCARD(builtin_time_zone_get_offset_string_for(global_object, &zoned_date_time->time_zone(), *instant));
+    return js_string(vm, move(offset_string));
 }
 
 // 15.6.10.2 get Temporal.ZonedDateTime.prototype.era, https://tc39.es/proposal-temporal/#sec-get-temporal.zoneddatetime.prototype.era
@@ -712,9 +674,7 @@ JS_DEFINE_NATIVE_FUNCTION(ZonedDateTimePrototype::era_getter)
     auto& calendar = zoned_date_time->calendar();
 
     // 6. Let plainDateTime be ? BuiltinTimeZoneGetPlainDateTimeFor(timeZone, instant, calendar).
-    auto* plain_date_time = builtin_time_zone_get_plain_date_time_for(global_object, &time_zone, *instant, calendar);
-    if (vm.exception())
-        return {};
+    auto* plain_date_time = TRY_OR_DISCARD(builtin_time_zone_get_plain_date_time_for(global_object, &time_zone, *instant, calendar));
 
     // 7. Return ? CalendarEra(calendar, plainDateTime).
     return calendar_era(global_object, calendar, *plain_date_time);
@@ -739,9 +699,7 @@ JS_DEFINE_NATIVE_FUNCTION(ZonedDateTimePrototype::era_year_getter)
     auto& calendar = zoned_date_time->calendar();
 
     // 6. Let plainDateTime be ? BuiltinTimeZoneGetPlainDateTimeFor(timeZone, instant, calendar).
-    auto* plain_date_time = builtin_time_zone_get_plain_date_time_for(global_object, &time_zone, *instant, calendar);
-    if (vm.exception())
-        return {};
+    auto* plain_date_time = TRY_OR_DISCARD(builtin_time_zone_get_plain_date_time_for(global_object, &time_zone, *instant, calendar));
 
     // 7. Return ? CalendarEraYear(calendar, plainDateTime).
     return calendar_era_year(global_object, calendar, *plain_date_time);
@@ -787,9 +745,7 @@ JS_DEFINE_NATIVE_FUNCTION(ZonedDateTimePrototype::to_plain_date)
     auto& calendar = zoned_date_time->calendar();
 
     // 6. Let temporalDateTime be ? BuiltinTimeZoneGetPlainDateTimeFor(timeZone, instant, calendar).
-    auto* temporal_date_time = builtin_time_zone_get_plain_date_time_for(global_object, &time_zone, *instant, calendar);
-    if (vm.exception())
-        return {};
+    auto* temporal_date_time = TRY_OR_DISCARD(builtin_time_zone_get_plain_date_time_for(global_object, &time_zone, *instant, calendar));
 
     // 7. Return ? CreateTemporalDate(temporalDateTime.[[ISOYear]], temporalDateTime.[[ISOMonth]], temporalDateTime.[[ISODay]], calendar).
     return create_temporal_date(global_object, temporal_date_time->iso_year(), temporal_date_time->iso_month(), temporal_date_time->iso_day(), calendar);
@@ -814,9 +770,7 @@ JS_DEFINE_NATIVE_FUNCTION(ZonedDateTimePrototype::to_plain_time)
     auto& calendar = zoned_date_time->calendar();
 
     // 6. Let temporalDateTime be ? BuiltinTimeZoneGetPlainDateTimeFor(timeZone, instant, zonedDateTime.[[Calendar]]).
-    auto* temporal_date_time = builtin_time_zone_get_plain_date_time_for(global_object, &time_zone, *instant, calendar);
-    if (vm.exception())
-        return {};
+    auto* temporal_date_time = TRY_OR_DISCARD(builtin_time_zone_get_plain_date_time_for(global_object, &time_zone, *instant, calendar));
 
     // 7. Return ? CreateTemporalTime(temporalDateTime.[[ISOHour]], temporalDateTime.[[ISOMinute]], temporalDateTime.[[ISOSecond]], temporalDateTime.[[ISOMillisecond]], temporalDateTime.[[ISOMicrosecond]], temporalDateTime.[[ISONanosecond]]).
     return create_temporal_time(global_object, temporal_date_time->iso_hour(), temporal_date_time->iso_minute(), temporal_date_time->iso_second(), temporal_date_time->iso_millisecond(), temporal_date_time->iso_microsecond(), temporal_date_time->iso_nanosecond());
@@ -838,7 +792,7 @@ JS_DEFINE_NATIVE_FUNCTION(ZonedDateTimePrototype::to_plain_date_time)
     auto* instant = create_temporal_instant(global_object, zoned_date_time->nanoseconds());
 
     // 5. Return ? BuiltinTimeZoneGetPlainDateTimeFor(timeZone, instant, zonedDateTime.[[Calendar]]).
-    return builtin_time_zone_get_plain_date_time_for(global_object, &time_zone, *instant, zoned_date_time->calendar());
+    return TRY_OR_DISCARD(builtin_time_zone_get_plain_date_time_for(global_object, &time_zone, *instant, zoned_date_time->calendar()));
 }
 
 // 6.3.50 Temporal.ZonedDateTime.prototype.toPlainYearMonth ( ), https://tc39.es/proposal-temporal/#sec-temporal.zoneddatetime.prototype.toplainyearmonth
@@ -860,9 +814,7 @@ JS_DEFINE_NATIVE_FUNCTION(ZonedDateTimePrototype::to_plain_year_month)
     auto& calendar = zoned_date_time->calendar();
 
     // 6. Let temporalDateTime be ? BuiltinTimeZoneGetPlainDateTimeFor(timeZone, instant, calendar).
-    auto* temporal_date_time = builtin_time_zone_get_plain_date_time_for(global_object, &time_zone, *instant, calendar);
-    if (vm.exception())
-        return {};
+    auto* temporal_date_time = TRY_OR_DISCARD(builtin_time_zone_get_plain_date_time_for(global_object, &time_zone, *instant, calendar));
 
     // 7. Let fieldNames be ? CalendarFields(calendar, « "monthCode", "year" »).
     auto field_names = calendar_fields(global_object, calendar, { "monthCode"sv, "year"sv });
@@ -897,9 +849,7 @@ JS_DEFINE_NATIVE_FUNCTION(ZonedDateTimePrototype::to_plain_month_day)
     auto& calendar = zoned_date_time->calendar();
 
     // 6. Let temporalDateTime be ? BuiltinTimeZoneGetPlainDateTimeFor(timeZone, instant, calendar).
-    auto* temporal_date_time = builtin_time_zone_get_plain_date_time_for(global_object, &time_zone, *instant, calendar);
-    if (vm.exception())
-        return {};
+    auto* temporal_date_time = TRY_OR_DISCARD(builtin_time_zone_get_plain_date_time_for(global_object, &time_zone, *instant, calendar));
 
     // 7. Let fieldNames be ? CalendarFields(calendar, « "day", "monthCode" »).
     auto field_names = calendar_fields(global_object, calendar, { "day"sv, "monthCode"sv });
@@ -937,15 +887,10 @@ JS_DEFINE_NATIVE_FUNCTION(ZonedDateTimePrototype::get_iso_fields)
     auto& calendar = zoned_date_time->calendar();
 
     // 7. Let dateTime be ? BuiltinTimeZoneGetPlainDateTimeFor(timeZone, instant, calendar).
-    auto* date_time = builtin_time_zone_get_plain_date_time_for(global_object, &time_zone, *instant, calendar);
-    if (vm.exception())
-        return {};
+    auto* date_time = TRY_OR_DISCARD(builtin_time_zone_get_plain_date_time_for(global_object, &time_zone, *instant, calendar));
 
     // 8. Let offset be ? BuiltinTimeZoneGetOffsetStringFor(timeZone, instant).
-    auto maybe_offset = builtin_time_zone_get_offset_string_for(global_object, &time_zone, *instant);
-    if (vm.exception())
-        return {};
-    auto offset = move(*maybe_offset);
+    auto offset = TRY_OR_DISCARD(builtin_time_zone_get_offset_string_for(global_object, &time_zone, *instant));
 
     // 9. Perform ! CreateDataPropertyOrThrow(fields, "calendar", calendar).
     fields->create_data_property_or_throw(vm.names.calendar, Value(&calendar));