1 files changed, 37 insertions, 0 deletions
diff --git a/js/src/tests/test262/built-ins/Temporal/PlainDate/prototype/toZonedDateTime/argument-string-time-designator-required-for-disambiguation.js b/js/src/tests/test262/built-ins/Temporal/PlainDate/prototype/toZonedDateTime/argument-string-time-designator-required-for-disambiguation.js
new file mode 100644
index 0000000000..99693c739d
--- /dev/null
+++ b/js/src/tests/test262/built-ins/Temporal/PlainDate/prototype/toZonedDateTime/argument-string-time-designator-required-for-disambiguation.js
@@ -0,0 +1,37 @@
+// |reftest| skip-if(!this.hasOwnProperty('Temporal')) -- Temporal is not enabled unconditionally
+// Copyright (C) 2022 Igalia, S.L. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+esid: sec-temporal.plaindate.prototype.tozoneddatetime
+description: ISO 8601 time designator "T" required in cases of ambiguity
+includes: [temporalHelpers.js]
+features: [Temporal, arrow-function]
+---*/
+
+const instance = new Temporal.PlainDate(2000, 5, 2);
+
+TemporalHelpers.ISO.plainTimeStringsAmbiguous().forEach((string) => {
+  let arg = string;
+  assert.throws(
+    RangeError,
+    () => instance.toZonedDateTime({ plainTime: arg, timeZone: "UTC" }),
+    `'${arg}' is ambiguous and requires T prefix`
+  );
+  // The same string with a T prefix should not throw:
+  arg = `T${string}`;
+  instance.toZonedDateTime({ plainTime: arg, timeZone: "UTC" });
+
+  arg = ` ${string}`;
+  assert.throws(
+    RangeError,
+    () => instance.toZonedDateTime({ plainTime: arg, timeZone: "UTC" }),
+    `space is not accepted as a substitute for T prefix: '${arg}'`
+  );
+});
+
+// None of these should throw without a T prefix, because they are unambiguously time strings:
+TemporalHelpers.ISO.plainTimeStringsUnambiguous().forEach(
+  (arg) => instance.toZonedDateTime({ plainTime: arg, timeZone: "UTC" }));
+
+reportCompare(0, 0);