From 0232d97415ea8334709d6c90d98acf33c302b8d5 Mon Sep 17 00:00:00 2001
From: Mike Pennisi <mike@mikepennisi.com>
Date: Fri, 10 Sep 2021 17:25:34 -0400
Subject: [PATCH] Add tests for Temporal.Now.plainDateTimeISO

---
 .../Now/plainDateTimeISO/extensible.js        | 12 +++
 .../Temporal/Now/plainDateTimeISO/length.js   | 25 ++++++
 .../Temporal/Now/plainDateTimeISO/name.js     | 20 +++++
 .../Now/plainDateTimeISO/not-a-constructor.js | 14 ++++
 .../Now/plainDateTimeISO/prop-desc.js         | 14 ++++
 .../Now/plainDateTimeISO/return-value.js      | 18 +++++
 .../plainDateTimeISO/time-zone-undefined.js   | 35 +++++++++
 ...zone-getoffsetnanosecondsfor-invocation.js | 28 +++++++
 ...one-getoffsetnanosecondsfor-non-integer.js | 17 ++++
 ...zone-getoffsetnanosecondsfor-non-method.js | 15 ++++
 ...ne-getoffsetnanosecondsfor-not-a-number.js | 37 +++++++++
 ...ne-getoffsetnanosecondsfor-out-of-range.js | 17 ++++
 ...mezone-getoffsetnanosecondsfor-poisoned.js | 17 ++++
 ...timezone-getoffsetnanosecondsfor-throws.js | 17 ++++
 ...zone-getoffsetnanosecondsfor-wrong-type.js | 21 +++++
 .../timezone-object-fail-call-tostring.js     | 20 +++++
 .../timezone-object-fail-get-timezone.js      | 17 ++++
 ...imezone-object-fail-has-nested-timezone.js | 21 +++++
 .../timezone-object-fail-has-timezone.js      | 19 +++++
 .../Now/plainDateTimeISO/timezone-object.js   | 77 +++++++++++++++++++
 .../timezone-string-datetime.js               | 24 ++++++
 21 files changed, 485 insertions(+)
 create mode 100644 test/built-ins/Temporal/Now/plainDateTimeISO/extensible.js
 create mode 100644 test/built-ins/Temporal/Now/plainDateTimeISO/length.js
 create mode 100644 test/built-ins/Temporal/Now/plainDateTimeISO/name.js
 create mode 100644 test/built-ins/Temporal/Now/plainDateTimeISO/not-a-constructor.js
 create mode 100644 test/built-ins/Temporal/Now/plainDateTimeISO/prop-desc.js
 create mode 100644 test/built-ins/Temporal/Now/plainDateTimeISO/return-value.js
 create mode 100644 test/built-ins/Temporal/Now/plainDateTimeISO/time-zone-undefined.js
 create mode 100644 test/built-ins/Temporal/Now/plainDateTimeISO/timezone-getoffsetnanosecondsfor-invocation.js
 create mode 100644 test/built-ins/Temporal/Now/plainDateTimeISO/timezone-getoffsetnanosecondsfor-non-integer.js
 create mode 100644 test/built-ins/Temporal/Now/plainDateTimeISO/timezone-getoffsetnanosecondsfor-non-method.js
 create mode 100644 test/built-ins/Temporal/Now/plainDateTimeISO/timezone-getoffsetnanosecondsfor-not-a-number.js
 create mode 100644 test/built-ins/Temporal/Now/plainDateTimeISO/timezone-getoffsetnanosecondsfor-out-of-range.js
 create mode 100644 test/built-ins/Temporal/Now/plainDateTimeISO/timezone-getoffsetnanosecondsfor-poisoned.js
 create mode 100644 test/built-ins/Temporal/Now/plainDateTimeISO/timezone-getoffsetnanosecondsfor-throws.js
 create mode 100644 test/built-ins/Temporal/Now/plainDateTimeISO/timezone-getoffsetnanosecondsfor-wrong-type.js
 create mode 100644 test/built-ins/Temporal/Now/plainDateTimeISO/timezone-object-fail-call-tostring.js
 create mode 100644 test/built-ins/Temporal/Now/plainDateTimeISO/timezone-object-fail-get-timezone.js
 create mode 100644 test/built-ins/Temporal/Now/plainDateTimeISO/timezone-object-fail-has-nested-timezone.js
 create mode 100644 test/built-ins/Temporal/Now/plainDateTimeISO/timezone-object-fail-has-timezone.js
 create mode 100644 test/built-ins/Temporal/Now/plainDateTimeISO/timezone-object.js
 create mode 100644 test/built-ins/Temporal/Now/plainDateTimeISO/timezone-string-datetime.js

diff --git a/test/built-ins/Temporal/Now/plainDateTimeISO/extensible.js b/test/built-ins/Temporal/Now/plainDateTimeISO/extensible.js
new file mode 100644
index 0000000000..91742a5556
--- /dev/null
+++ b/test/built-ins/Temporal/Now/plainDateTimeISO/extensible.js
@@ -0,0 +1,12 @@
+// Copyright (C) 2021 the V8 project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+/*---
+esid: sec-temporal.now.plaindatetimeiso
+description: Temporal.Now.plainDateTimeISO is extensible.
+features: [Temporal]
+---*/
+
+assert(
+  Object.isExtensible(Temporal.Now.plainDateTimeISO),
+  'Object.isExtensible(Temporal.Now.plainDateTimeISO) must return true'
+);
diff --git a/test/built-ins/Temporal/Now/plainDateTimeISO/length.js b/test/built-ins/Temporal/Now/plainDateTimeISO/length.js
new file mode 100644
index 0000000000..50b51971b2
--- /dev/null
+++ b/test/built-ins/Temporal/Now/plainDateTimeISO/length.js
@@ -0,0 +1,25 @@
+// Copyright (C) 2020 Igalia, S.L. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+esid: sec-temporal.now.plaindatetimeiso
+description: The `length` property of Temporal.Now.plainDateTimeISO
+info: |
+    Every built-in function object, including constructors, has a "length" property whose value is
+    an integer. Unless otherwise specified, this value is equal to the largest number of named
+    arguments shown in the subclause headings for the function description. Optional parameters
+    (which are indicated with brackets: [ ]) or rest parameters (which are shown using the form
+    «...name») are not included in the default argument count.
+
+    Unless otherwise specified, the "length" property of a built-in function object has the
+    attributes { [[Writable]]: false, [[Enumerable]]: false, [[Configurable]]: true }.
+includes: [propertyHelper.js]
+features: [Temporal]
+---*/
+
+verifyProperty(Temporal.Now.plainDateTimeISO, "length", {
+  value: 0,
+  writable: false,
+  enumerable: false,
+  configurable: true,
+});
diff --git a/test/built-ins/Temporal/Now/plainDateTimeISO/name.js b/test/built-ins/Temporal/Now/plainDateTimeISO/name.js
new file mode 100644
index 0000000000..dc3dbb4651
--- /dev/null
+++ b/test/built-ins/Temporal/Now/plainDateTimeISO/name.js
@@ -0,0 +1,20 @@
+// Copyright (C) 2021 the V8 project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+/*---
+esid: sec-temporal.now.plainDateTimeISO
+description: Temporal.Now.plainDateTimeISO.name is "plainDateTimeISO".
+includes: [propertyHelper.js]
+features: [Temporal]
+---*/
+
+assert.sameValue(
+  Temporal.Now.plainDateTimeISO.name,
+  'plainDateTimeISO',
+  'The value of Temporal.Now.plainDateTimeISO.name is expected to be "plainDateTimeISO"'
+);
+
+verifyProperty(Temporal.Now.plainDateTimeISO, 'name', {
+  enumerable: false,
+  writable: false,
+  configurable: true
+});
diff --git a/test/built-ins/Temporal/Now/plainDateTimeISO/not-a-constructor.js b/test/built-ins/Temporal/Now/plainDateTimeISO/not-a-constructor.js
new file mode 100644
index 0000000000..e432b8970a
--- /dev/null
+++ b/test/built-ins/Temporal/Now/plainDateTimeISO/not-a-constructor.js
@@ -0,0 +1,14 @@
+// Copyright (C) 2021 the V8 project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+/*---
+esid: sec-temporal.now.plaindatetimeiso
+description: Temporal.Now.plainDateTimeISO does not implement [[Construct]]
+includes: [isConstructor.js]
+features: [Reflect.construct, Temporal, arrow-function]
+---*/
+
+assert.sameValue(isConstructor(Temporal.Now.plainDateTimeISO), false, 'isConstructor(Temporal.Now.plainDateTimeISO) must return false');
+
+assert.throws(TypeError, () => {
+  new Temporal.Now.plainDateTimeISO();
+}, 'new Temporal.Now.plainDateTimeISO() throws a TypeError exception');
diff --git a/test/built-ins/Temporal/Now/plainDateTimeISO/prop-desc.js b/test/built-ins/Temporal/Now/plainDateTimeISO/prop-desc.js
new file mode 100644
index 0000000000..8f764a6bf0
--- /dev/null
+++ b/test/built-ins/Temporal/Now/plainDateTimeISO/prop-desc.js
@@ -0,0 +1,14 @@
+// Copyright (C) 2021 the V8 project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+/*---
+esid: sec-temporal.now.plaindatetimeiso
+description: The "plainDateTimeISO" property of Temporal.Now
+includes: [propertyHelper.js]
+features: [Temporal]
+---*/
+
+verifyProperty(Temporal.Now, 'plainDateTimeISO', {
+  enumerable: false,
+  writable: true,
+  configurable: true
+});
diff --git a/test/built-ins/Temporal/Now/plainDateTimeISO/return-value.js b/test/built-ins/Temporal/Now/plainDateTimeISO/return-value.js
new file mode 100644
index 0000000000..c0de72cb6d
--- /dev/null
+++ b/test/built-ins/Temporal/Now/plainDateTimeISO/return-value.js
@@ -0,0 +1,18 @@
+// Copyright (C) 2020 Igalia, S.L. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+/*---
+esid: sec-temporal.now.plaindatetimeiso
+description: Return value describes the start of a day
+features: [BigInt, Temporal]
+---*/
+const timeZone = {
+  getOffsetNanosecondsFor(instant) {
+    return -Number(instant.epochNanoseconds % 86400000000000n);
+  }
+};
+
+const result = Temporal.Now.plainDateTimeISO(timeZone);
+
+for (const property of ['hour', 'minute', 'second', 'millisecond', 'microsecond', 'nanosecond']) {
+  assert.sameValue(result[property], 0, 'The value of result[property] is expected to be 0');
+}
diff --git a/test/built-ins/Temporal/Now/plainDateTimeISO/time-zone-undefined.js b/test/built-ins/Temporal/Now/plainDateTimeISO/time-zone-undefined.js
new file mode 100644
index 0000000000..6d719c2e91
--- /dev/null
+++ b/test/built-ins/Temporal/Now/plainDateTimeISO/time-zone-undefined.js
@@ -0,0 +1,35 @@
+// Copyright (C) 2021 Igalia, S.L. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+esid: sec-temporal.now.plaindatetimeiso
+description: Functions when time zone argument is omitted
+includes: [compareArray.js]
+features: [Temporal]
+---*/
+
+const actual = [];
+const expected = [];
+
+Object.defineProperty(Temporal.TimeZone, "from", {
+  get() {
+    actual.push("get Temporal.TimeZone.from");
+    return undefined;
+  },
+});
+
+const resultExplicit = Temporal.Now.plainDateTimeISO(undefined);
+assert(
+  resultExplicit instanceof Temporal.PlainDateTime,
+  'The result of evaluating (resultExplicit instanceof Temporal.PlainDateTime) is expected to be true'
+);
+
+assert.compareArray(actual, expected, 'The value of actual is expected to equal the value of expected');
+
+const resultImplicit = Temporal.Now.plainDateTimeISO();
+assert(
+  resultImplicit instanceof Temporal.PlainDateTime,
+  'The result of evaluating (resultImplicit instanceof Temporal.PlainDateTime) is expected to be true'
+);
+
+assert.compareArray(actual, expected, 'The value of actual is expected to equal the value of expected');
diff --git a/test/built-ins/Temporal/Now/plainDateTimeISO/timezone-getoffsetnanosecondsfor-invocation.js b/test/built-ins/Temporal/Now/plainDateTimeISO/timezone-getoffsetnanosecondsfor-invocation.js
new file mode 100644
index 0000000000..4cf8cd2011
--- /dev/null
+++ b/test/built-ins/Temporal/Now/plainDateTimeISO/timezone-getoffsetnanosecondsfor-invocation.js
@@ -0,0 +1,28 @@
+// Copyright (C) 2021 the V8 project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+/*---
+esid: sec-temporal.now.plaindatetimeiso
+description: Correctly invokes `getOffsetNanosecondsFor` method of TimeZone-like objects
+features: [Temporal]
+---*/
+
+var calls = [];
+var timeZone = {
+  getOffsetNanosecondsFor: function() {
+    calls.push({
+      args: arguments,
+      this: this
+    });
+    return 0;
+  },
+};
+
+Temporal.Now.plainDateTimeISO(timeZone);
+
+assert.sameValue(calls.length, 1, 'The value of calls.length is expected to be 1');
+assert.sameValue(calls[0].args.length, 1, 'The value of calls[0].args.length is expected to be 1');
+assert(
+  calls[0].args[0] instanceof Temporal.Instant,
+  'The result of evaluating (calls[0].args[0] instanceof Temporal.Instant) is expected to be true'
+);
+assert.sameValue(calls[0].this, timeZone, 'The value of calls[0].this is expected to equal the value of timeZone');
diff --git a/test/built-ins/Temporal/Now/plainDateTimeISO/timezone-getoffsetnanosecondsfor-non-integer.js b/test/built-ins/Temporal/Now/plainDateTimeISO/timezone-getoffsetnanosecondsfor-non-integer.js
new file mode 100644
index 0000000000..4cbb76f254
--- /dev/null
+++ b/test/built-ins/Temporal/Now/plainDateTimeISO/timezone-getoffsetnanosecondsfor-non-integer.js
@@ -0,0 +1,17 @@
+// Copyright (C) 2021 Igalia, S.L. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+/*---
+esid: sec-temporal.now.plaindatetimeiso
+description: RangeError thrown if time zone reports an offset that is not an integer number of nanoseconds
+features: [Temporal, arrow-function]
+includes: [temporalHelpers.js]
+---*/
+[3600000000000.5, NaN].forEach(wrongOffset => {
+  const timeZone = TemporalHelpers.specificOffsetTimeZone(wrongOffset);
+
+  assert.throws(
+    RangeError,
+    () => Temporal.Now.plainDateTimeISO(timeZone),
+    'Temporal.Now.plainDateTimeISO(timeZone) throws a RangeError exception'
+  );
+});
diff --git a/test/built-ins/Temporal/Now/plainDateTimeISO/timezone-getoffsetnanosecondsfor-non-method.js b/test/built-ins/Temporal/Now/plainDateTimeISO/timezone-getoffsetnanosecondsfor-non-method.js
new file mode 100644
index 0000000000..9b46ca6c9d
--- /dev/null
+++ b/test/built-ins/Temporal/Now/plainDateTimeISO/timezone-getoffsetnanosecondsfor-non-method.js
@@ -0,0 +1,15 @@
+// Copyright (C) 2021 the V8 project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+/*---
+esid: sec-temporal.now.plaindatetimeiso
+description: Rejects when `getOffsetNanosecondsFor` property is not a method
+features: [Temporal]
+---*/
+
+var timeZone = {
+  getOffsetNanosecondsFor: 7
+};
+
+assert.throws(TypeError, function() {
+  Temporal.Now.plainDateTimeISO(timeZone);
+}, 'Temporal.Now.plainDateTimeISO(timeZone) throws a TypeError exception');
diff --git a/test/built-ins/Temporal/Now/plainDateTimeISO/timezone-getoffsetnanosecondsfor-not-a-number.js b/test/built-ins/Temporal/Now/plainDateTimeISO/timezone-getoffsetnanosecondsfor-not-a-number.js
new file mode 100644
index 0000000000..57f5304812
--- /dev/null
+++ b/test/built-ins/Temporal/Now/plainDateTimeISO/timezone-getoffsetnanosecondsfor-not-a-number.js
@@ -0,0 +1,37 @@
+// Copyright (C) 2020 Igalia, S.L. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+/*---
+esid: sec-temporal.now.plaindatetimeiso
+description: Rejects non-numeric nanosecond values reported by TimeZone-like object
+features: [BigInt, Symbol, Temporal, arrow-function]
+---*/
+const invalidValues = [
+  undefined,
+  null,
+  true,
+  '2020-01-01T12:45:36',
+  Symbol(),
+  2n,
+  {},
+  Temporal.PlainDateTime,
+  Temporal.PlainDateTime.prototype
+];
+
+for (const dateTime of invalidValues) {
+  let callCount = 0;
+
+  const timeZone = {
+    getOffsetNanosecondsFor(instant, calendar) {
+      callCount += 1;
+      return dateTime;
+    }
+  };
+
+  assert.throws(
+    TypeError,
+    () => Temporal.Now.plainDateTimeISO(timeZone),
+    'Temporal.Now.plainDateTimeISO(timeZone) throws a TypeError exception'
+  );
+
+  assert.sameValue(callCount, 1, 'The value of callCount is expected to be 1');
+}
diff --git a/test/built-ins/Temporal/Now/plainDateTimeISO/timezone-getoffsetnanosecondsfor-out-of-range.js b/test/built-ins/Temporal/Now/plainDateTimeISO/timezone-getoffsetnanosecondsfor-out-of-range.js
new file mode 100644
index 0000000000..7e2f9db70a
--- /dev/null
+++ b/test/built-ins/Temporal/Now/plainDateTimeISO/timezone-getoffsetnanosecondsfor-out-of-range.js
@@ -0,0 +1,17 @@
+// Copyright (C) 2021 Igalia, S.L. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+/*---
+esid: sec-temporal.now.plaindatetimeiso
+description: RangeError thrown if time zone reports an offset that is out of range
+features: [Temporal, arrow-function]
+includes: [temporalHelpers.js]
+---*/
+[-86400000000001, 86400000000001, -Infinity, Infinity].forEach(wrongOffset => {
+  const timeZone = TemporalHelpers.specificOffsetTimeZone(wrongOffset);
+
+  assert.throws(
+    RangeError,
+    () => Temporal.Now.plainDateTimeISO(timeZone),
+    'Temporal.Now.plainDateTimeISO(timeZone) throws a RangeError exception'
+  );
+});
diff --git a/test/built-ins/Temporal/Now/plainDateTimeISO/timezone-getoffsetnanosecondsfor-poisoned.js b/test/built-ins/Temporal/Now/plainDateTimeISO/timezone-getoffsetnanosecondsfor-poisoned.js
new file mode 100644
index 0000000000..822e6a6b6d
--- /dev/null
+++ b/test/built-ins/Temporal/Now/plainDateTimeISO/timezone-getoffsetnanosecondsfor-poisoned.js
@@ -0,0 +1,17 @@
+// Copyright (C) 2021 the V8 project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+/*---
+esid: sec-temporal.now.plaindatetimeiso
+description: Forwards error when accessing `getOffsetNanosecondsFor` property throws
+features: [Temporal]
+---*/
+
+var timeZone = {
+  get getOffsetNanosecondsFor() {
+    throw new Test262Error();
+  }
+};
+
+assert.throws(Test262Error, function() {
+  Temporal.Now.plainDateTimeISO(timeZone);
+}, 'Temporal.Now.plainDateTimeISO(timeZone) throws a Test262Error exception');
diff --git a/test/built-ins/Temporal/Now/plainDateTimeISO/timezone-getoffsetnanosecondsfor-throws.js b/test/built-ins/Temporal/Now/plainDateTimeISO/timezone-getoffsetnanosecondsfor-throws.js
new file mode 100644
index 0000000000..2c87fdf471
--- /dev/null
+++ b/test/built-ins/Temporal/Now/plainDateTimeISO/timezone-getoffsetnanosecondsfor-throws.js
@@ -0,0 +1,17 @@
+// Copyright (C) 2021 the V8 project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+/*---
+esid: sec-temporal.now.plaindatetimeiso
+description: Forwards error when `getOffsetNanosecondsFor` throws
+features: [Temporal]
+---*/
+
+var timeZone = {
+  getOffsetNanosecondsFor() {
+    throw new Test262Error();
+  }
+};
+
+assert.throws(Test262Error, function() {
+  Temporal.Now.plainDateTimeISO(timeZone);
+}, 'Temporal.Now.plainDateTimeISO(timeZone) throws a Test262Error exception');
diff --git a/test/built-ins/Temporal/Now/plainDateTimeISO/timezone-getoffsetnanosecondsfor-wrong-type.js b/test/built-ins/Temporal/Now/plainDateTimeISO/timezone-getoffsetnanosecondsfor-wrong-type.js
new file mode 100644
index 0000000000..6c31922e85
--- /dev/null
+++ b/test/built-ins/Temporal/Now/plainDateTimeISO/timezone-getoffsetnanosecondsfor-wrong-type.js
@@ -0,0 +1,21 @@
+// Copyright (C) 2021 Igalia, S.L. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+/*---
+esid: sec-temporal.now.plaindatetimeiso
+description: TypeError thrown if time zone reports an offset that is not a Number
+features: [BigInt, Symbol, Temporal, arrow-function]
+includes: [temporalHelpers.js]
+---*/
+[undefined, null, true, '+01:00', Symbol(), 3600000000000n, {}, {
+  valueOf() {
+    return 3600000000000;
+  }
+}].forEach(wrongOffset => {
+  const timeZone = TemporalHelpers.specificOffsetTimeZone(wrongOffset);
+
+  assert.throws(
+    TypeError,
+    () => Temporal.Now.plainDateTimeISO(timeZone),
+    'Temporal.Now.plainDateTimeISO(timeZone) throws a TypeError exception'
+  );
+});
diff --git a/test/built-ins/Temporal/Now/plainDateTimeISO/timezone-object-fail-call-tostring.js b/test/built-ins/Temporal/Now/plainDateTimeISO/timezone-object-fail-call-tostring.js
new file mode 100644
index 0000000000..80277327d2
--- /dev/null
+++ b/test/built-ins/Temporal/Now/plainDateTimeISO/timezone-object-fail-call-tostring.js
@@ -0,0 +1,20 @@
+// Copyright (C) 2021 the V8 project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+/*---
+esid: sec-temporal.now.plaindatetimeiso
+description: Forwards error thrown by invoking "toString" property
+features: [Temporal]
+---*/
+
+var timeZone = {
+  timeZone: {
+    timeZone: true,
+    toString: function() {
+      throw new Test262Error();
+    },
+  }
+};
+
+assert.throws(Test262Error, function() {
+  Temporal.Now.plainDateTimeISO(timeZone);
+}, 'Temporal.Now.plainDateTimeISO(timeZone) throws a Test262Error exception');
diff --git a/test/built-ins/Temporal/Now/plainDateTimeISO/timezone-object-fail-get-timezone.js b/test/built-ins/Temporal/Now/plainDateTimeISO/timezone-object-fail-get-timezone.js
new file mode 100644
index 0000000000..37cc21b8cc
--- /dev/null
+++ b/test/built-ins/Temporal/Now/plainDateTimeISO/timezone-object-fail-get-timezone.js
@@ -0,0 +1,17 @@
+// Copyright (C) 2021 the V8 project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+/*---
+esid: sec-temporal.now.plaindatetimeiso
+description: Forwards error thrown by retrieving value of "timeZone" property
+features: [Temporal]
+---*/
+
+var timeZone = {
+  get timeZone() {
+    throw new Test262Error();
+  },
+};
+
+assert.throws(Test262Error, function() {
+  Temporal.Now.plainDateTimeISO(timeZone);
+}, 'Temporal.Now.plainDateTimeISO(timeZone) throws a Test262Error exception');
diff --git a/test/built-ins/Temporal/Now/plainDateTimeISO/timezone-object-fail-has-nested-timezone.js b/test/built-ins/Temporal/Now/plainDateTimeISO/timezone-object-fail-has-nested-timezone.js
new file mode 100644
index 0000000000..dc75b42302
--- /dev/null
+++ b/test/built-ins/Temporal/Now/plainDateTimeISO/timezone-object-fail-has-nested-timezone.js
@@ -0,0 +1,21 @@
+// Copyright (C) 2021 the V8 project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+/*---
+esid: sec-temporal.now.plaindatetimeiso
+description: Forwards error thrown by checking presence of nested "timeZone" property
+features: [Proxy, Temporal]
+---*/
+
+var timeZone = {
+  timeZone: new Proxy({}, {
+    has: function(target, property) {
+      if (property === 'timeZone') {
+        throw new Test262Error();
+      }
+    },
+  })
+};
+
+assert.throws(Test262Error, function() {
+  Temporal.Now.plainDateTimeISO(timeZone);
+}, 'Temporal.Now.plainDateTimeISO(timeZone) throws a Test262Error exception');
diff --git a/test/built-ins/Temporal/Now/plainDateTimeISO/timezone-object-fail-has-timezone.js b/test/built-ins/Temporal/Now/plainDateTimeISO/timezone-object-fail-has-timezone.js
new file mode 100644
index 0000000000..86850e3c79
--- /dev/null
+++ b/test/built-ins/Temporal/Now/plainDateTimeISO/timezone-object-fail-has-timezone.js
@@ -0,0 +1,19 @@
+// Copyright (C) 2021 the V8 project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+/*---
+esid: sec-temporal.now.plaindatetimeiso
+description: Forwards error thrown by checking presence of "timeZone" property
+features: [Proxy, Temporal]
+---*/
+
+var timeZone = new Proxy({}, {
+  has: function(target, property) {
+    if (property === 'timeZone') {
+      throw new Test262Error();
+    }
+  },
+});
+
+assert.throws(Test262Error, function() {
+  Temporal.Now.plainDateTimeISO(timeZone);
+}, 'Temporal.Now.plainDateTimeISO(timeZone) throws a Test262Error exception');
diff --git a/test/built-ins/Temporal/Now/plainDateTimeISO/timezone-object.js b/test/built-ins/Temporal/Now/plainDateTimeISO/timezone-object.js
new file mode 100644
index 0000000000..f81bd4ad15
--- /dev/null
+++ b/test/built-ins/Temporal/Now/plainDateTimeISO/timezone-object.js
@@ -0,0 +1,77 @@
+// Copyright (C) 2020 Igalia, S.L. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+/*---
+esid: sec-temporal.now.plaindatetimeiso
+description: Observable interactions with the provided timezone-like object
+includes: [compareArray.js]
+features: [BigInt, Proxy, Temporal]
+---*/
+const actual = [];
+
+const expected = [
+  'has timeZone.timeZone',
+  'get timeZone.timeZone',
+  'has nestedTimeZone.timeZone',
+  'get nestedTimeZone.getOffsetNanosecondsFor',
+  'call nestedTimeZone.getOffsetNanosecondsFor'
+];
+
+const nestedTimeZone = new Proxy({
+  getOffsetNanosecondsFor(instant) {
+    actual.push('call nestedTimeZone.getOffsetNanosecondsFor');
+
+    assert.sameValue(
+      instant instanceof Temporal.Instant,
+      true,
+      'The result of evaluating (instant instanceof Temporal.Instant) is expected to be true'
+    );
+
+    return -Number(instant.epochNanoseconds % 86400000000000n);
+  }
+}, {
+  has(target, property) {
+    actual.push(`has nestedTimeZone.${String(property)}`);
+    return property in target;
+  },
+
+  get(target, property) {
+    actual.push(`get nestedTimeZone.${String(property)}`);
+    return target[property];
+  }
+});
+
+const timeZone = new Proxy({
+  timeZone: nestedTimeZone,
+
+  getOffsetNanosecondsFor(instant) {
+    actual.push('call timeZone.getOffsetNanosecondsFor');
+
+    assert.sameValue(
+      instant instanceof Temporal.Instant,
+      true,
+      'The result of evaluating (instant instanceof Temporal.Instant) is expected to be true'
+    );
+
+    return -Number(instant.epochNanoseconds % 86400000000000n);
+  }
+}, {
+  has(target, property) {
+    actual.push(`has timeZone.${property}`);
+    return property in target;
+  },
+
+  get(target, property) {
+    actual.push(`get timeZone.${property}`);
+    return target[property];
+  }
+});
+
+Object.defineProperty(Temporal.TimeZone, 'from', {
+  get() {
+    actual.push('get Temporal.TimeZone.from');
+    return undefined;
+  }
+});
+
+Temporal.Now.plainDateTimeISO(timeZone);
+assert.compareArray(actual, expected, 'The value of actual is expected to equal the value of expected');
diff --git a/test/built-ins/Temporal/Now/plainDateTimeISO/timezone-string-datetime.js b/test/built-ins/Temporal/Now/plainDateTimeISO/timezone-string-datetime.js
new file mode 100644
index 0000000000..5c1515d888
--- /dev/null
+++ b/test/built-ins/Temporal/Now/plainDateTimeISO/timezone-string-datetime.js
@@ -0,0 +1,24 @@
+// Copyright (C) 2021 Igalia, S.L. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+/*---
+esid: sec-temporal.now.plaindatetimeiso
+description: Conversion of ISO date-time strings to Temporal.TimeZone instances
+features: [Temporal]
+---*/
+
+let timeZone = "2021-08-19T17:30";
+assert.throws(RangeError, () => Temporal.Now.plainDateTimeISO(timeZone), "bare date-time string is not a time zone");
+assert.throws(RangeError, () => Temporal.Now.plainDateTimeISO({ timeZone }), "bare date-time string is not a time zone");
+
+// The following are all valid strings so should not throw:
+
+[
+  "2021-08-19T17:30Z",
+  "2021-08-19T17:30-07:00",
+  "2021-08-19T17:30[America/Vancouver]",
+  "2021-08-19T17:30Z[America/Vancouver]",
+  "2021-08-19T17:30-07:00[America/Vancouver]",
+].forEach((timeZone) => {
+  Temporal.Now.plainDateTimeISO(timeZone);
+  Temporal.Now.plainDateTimeISO({ timeZone });
+});