Temporal: Move tests for getNext/PreviousTransition into ZonedDateTime

See: tc39/proposal-temporal#2826

test/built-ins/Temporal/TimeZone/prototype/getNextTransition/branding.js

@@ -1,24 +0,0 @@
-// 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.timezone.prototype.getnexttransition
-description: Throw a TypeError if the receiver is invalid
-features: [Symbol, Temporal]
----*/
-
-const getNextTransition = Temporal.TimeZone.prototype.getNextTransition;
-
-assert.sameValue(typeof getNextTransition, "function");
-
-const args = [new Temporal.Instant(0n)];
-
-assert.throws(TypeError, () => getNextTransition.apply(undefined, args), "undefined");
-assert.throws(TypeError, () => getNextTransition.apply(null, args), "null");
-assert.throws(TypeError, () => getNextTransition.apply(true, args), "true");
-assert.throws(TypeError, () => getNextTransition.apply("", args), "empty string");
-assert.throws(TypeError, () => getNextTransition.apply(Symbol(), args), "symbol");
-assert.throws(TypeError, () => getNextTransition.apply(1, args), "1");
-assert.throws(TypeError, () => getNextTransition.apply({}, args), "plain object");
-assert.throws(TypeError, () => getNextTransition.apply(Temporal.TimeZone, args), "Temporal.TimeZone");
-assert.throws(TypeError, () => getNextTransition.apply(Temporal.TimeZone.prototype, args), "Temporal.TimeZone.prototype");

test/built-ins/Temporal/TimeZone/prototype/getNextTransition/builtin.js

@@ -1,33 +0,0 @@
-// 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.timezone.prototype.getnexttransition
-description: >
-    Tests that Temporal.TimeZone.prototype.getNextTransition
-    meets the requirements for built-in objects defined by the
-    introduction of chapter 17 of the ECMAScript Language Specification.
-info: |
-    Built-in functions that are not constructors do not have a "prototype" property unless
-    otherwise specified in the description of a particular function.
-
-    Unless specified otherwise, a built-in object that is callable as a function is a built-in
-    function object with the characteristics described in 10.3. Unless specified otherwise, the
-    [[Extensible]] internal slot of a built-in object initially has the value true.
-
-    Unless otherwise specified every built-in function and every built-in constructor has the
-    Function prototype object [...] as the value of its [[Prototype]] internal slot.
-features: [Temporal]
----*/
-
-assert.sameValue(Object.isExtensible(Temporal.TimeZone.prototype.getNextTransition),
-  true, "Built-in objects must be extensible.");
-
-assert.sameValue(Object.prototype.toString.call(Temporal.TimeZone.prototype.getNextTransition),
-  "[object Function]", "Object.prototype.toString");
-
-assert.sameValue(Object.getPrototypeOf(Temporal.TimeZone.prototype.getNextTransition),
-  Function.prototype, "prototype");
-
-assert.sameValue(Temporal.TimeZone.prototype.getNextTransition.hasOwnProperty("prototype"),
-  false, "prototype property");

test/built-ins/Temporal/TimeZone/prototype/getNextTransition/length.js

@@ -1,25 +0,0 @@
-// 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.timezone.prototype.getnexttransition
-description: Temporal.TimeZone.prototype.getNextTransition.length is 1
-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.TimeZone.prototype.getNextTransition, "length", {
-  value: 1,
-  writable: false,
-  enumerable: false,
-  configurable: true,
-});

test/built-ins/Temporal/TimeZone/prototype/getNextTransition/name.js

@@ -1,23 +0,0 @@
-// 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.timezone.prototype.getnexttransition
-description: Temporal.TimeZone.prototype.getNextTransition.name is "getNextTransition".
-info: |
-    Every built-in function object, including constructors, that is not identified as an anonymous
-    function has a "name" property whose value is a String. Unless otherwise specified, this value
-    is the name that is given to the function in this specification.
-
-    Unless otherwise specified, the "name" property of a built-in function object, if it exists,
-    has the attributes { [[Writable]]: false, [[Enumerable]]: false, [[Configurable]]: true }.
-includes: [propertyHelper.js]
-features: [Temporal]
----*/
-
-verifyProperty(Temporal.TimeZone.prototype.getNextTransition, "name", {
-  value: "getNextTransition",
-  writable: false,
-  enumerable: false,
-  configurable: true,
-});

test/built-ins/Temporal/TimeZone/prototype/getNextTransition/not-a-constructor.js

@@ -1,21 +0,0 @@
-// 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.timezone.prototype.getnexttransition
-description: >
-  Temporal.TimeZone.prototype.getNextTransition does not implement [[Construct]], is not new-able
-info: |
-    Built-in function objects that are not identified as constructors do not implement the
-    [[Construct]] internal method unless otherwise specified in the description of a particular
-    function.
-includes: [isConstructor.js]
-features: [Reflect.construct, Temporal]
----*/
-
-assert.throws(TypeError, () => {
-  new Temporal.TimeZone.prototype.getNextTransition();
-}, "Calling as constructor");
-
-assert.sameValue(isConstructor(Temporal.TimeZone.prototype.getNextTransition), false,
-  "isConstructor(Temporal.TimeZone.prototype.getNextTransition)");

test/built-ins/Temporal/TimeZone/prototype/getNextTransition/prop-desc.js

@@ -1,21 +0,0 @@
-// 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.timezone.prototype.getnexttransition
-description: The "getNextTransition" property of Temporal.TimeZone.prototype
-includes: [propertyHelper.js]
-features: [Temporal]
----*/
-
-assert.sameValue(
-  typeof Temporal.TimeZone.prototype.getNextTransition,
-  "function",
-  "`typeof TimeZone.prototype.getNextTransition` is `function`"
-);
-
-verifyProperty(Temporal.TimeZone.prototype, "getNextTransition", {
-  writable: true,
-  enumerable: false,
-  configurable: true,
-});

test/built-ins/Temporal/TimeZone/prototype/getPreviousTransition/branding.js

@@ -1,24 +0,0 @@
-// 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.timezone.prototype.getprevioustransition
-description: Throw a TypeError if the receiver is invalid
-features: [Symbol, Temporal]
----*/
-
-const getPreviousTransition = Temporal.TimeZone.prototype.getPreviousTransition;
-
-assert.sameValue(typeof getPreviousTransition, "function");
-
-const args = [new Temporal.Instant(0n)];
-
-assert.throws(TypeError, () => getPreviousTransition.apply(undefined, args), "undefined");
-assert.throws(TypeError, () => getPreviousTransition.apply(null, args), "null");
-assert.throws(TypeError, () => getPreviousTransition.apply(true, args), "true");
-assert.throws(TypeError, () => getPreviousTransition.apply("", args), "empty string");
-assert.throws(TypeError, () => getPreviousTransition.apply(Symbol(), args), "symbol");
-assert.throws(TypeError, () => getPreviousTransition.apply(1, args), "1");
-assert.throws(TypeError, () => getPreviousTransition.apply({}, args), "plain object");
-assert.throws(TypeError, () => getPreviousTransition.apply(Temporal.TimeZone, args), "Temporal.TimeZone");
-assert.throws(TypeError, () => getPreviousTransition.apply(Temporal.TimeZone.prototype, args), "Temporal.TimeZone.prototype");

test/built-ins/Temporal/TimeZone/prototype/getPreviousTransition/prop-desc.js

@@ -1,21 +0,0 @@
-// 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.timezone.prototype.getprevioustransition
-description: The "getPreviousTransition" property of Temporal.TimeZone.prototype
-includes: [propertyHelper.js]
-features: [Temporal]
----*/
-
-assert.sameValue(
-  typeof Temporal.TimeZone.prototype.getPreviousTransition,
-  "function",
-  "`typeof TimeZone.prototype.getPreviousTransition` is `function`"
-);
-
-verifyProperty(Temporal.TimeZone.prototype, "getPreviousTransition", {
-  writable: true,
-  enumerable: false,
-  configurable: true,
-});

test/built-ins/Temporal/ZonedDateTime/prototype/getTimeZoneTransition/branding.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.zoneddatetime.prototype.gettimezonetransition
+description: Throw a TypeError if the receiver is invalid
+features: [Symbol, Temporal]
+---*/
+
+const getTimeZoneTransition = Temporal.ZonedDateTime.prototype.getTimeZoneTransition;
+
+assert.sameValue(typeof getTimeZoneTransition, "function");
+
+const args = ["next"];
+
+assert.throws(TypeError, () => getTimeZoneTransition.apply(undefined, args), "undefined");
+assert.throws(TypeError, () => getTimeZoneTransition.apply(null, args), "null");
+assert.throws(TypeError, () => getTimeZoneTransition.apply(true, args), "true");
+assert.throws(TypeError, () => getTimeZoneTransition.apply("", args), "empty string");
+assert.throws(TypeError, () => getTimeZoneTransition.apply(Symbol(), args), "symbol");
+assert.throws(TypeError, () => getTimeZoneTransition.apply(1, args), "1");
+assert.throws(TypeError, () => getTimeZoneTransition.apply({}, args), "plain object");
+assert.throws(TypeError, () => getTimeZoneTransition.apply(Temporal.ZonedDateTime, args), "Temporal.ZonedDateTime");
+assert.throws(TypeError, () => getTimeZoneTransition.apply(Temporal.ZonedDateTime.prototype, args), "Temporal.ZonedDateTime.prototype");

test/built-ins/Temporal/ZonedDateTime/prototype/getTimeZoneTransition/builtin.js

@@ -2,9 +2,9 @@
 // This code is governed by the BSD license found in the LICENSE file.
 
 /*---
-esid: sec-temporal.timezone.prototype.getprevioustransition
+esid: sec-temporal.zoneddatetime.prototype.gettimezonetransition
 description: >
-    Tests that Temporal.TimeZone.prototype.getPreviousTransition
+    Tests that Temporal.ZonedDateTime.prototype.getTimeZoneTransition
     meets the requirements for built-in objects defined by the
     introduction of chapter 17 of the ECMAScript Language Specification.
 info: |
@@ -20,14 +20,14 @@ info: |
 features: [Temporal]
 ---*/
 
-assert.sameValue(Object.isExtensible(Temporal.TimeZone.prototype.getPreviousTransition),
+assert.sameValue(Object.isExtensible(Temporal.ZonedDateTime.prototype.getTimeZoneTransition),
   true, "Built-in objects must be extensible.");
 
-assert.sameValue(Object.prototype.toString.call(Temporal.TimeZone.prototype.getPreviousTransition),
+assert.sameValue(Object.prototype.toString.call(Temporal.ZonedDateTime.prototype.getTimeZoneTransition),
   "[object Function]", "Object.prototype.toString");
 
-assert.sameValue(Object.getPrototypeOf(Temporal.TimeZone.prototype.getPreviousTransition),
+assert.sameValue(Object.getPrototypeOf(Temporal.ZonedDateTime.prototype.getTimeZoneTransition),
   Function.prototype, "prototype");
 
-assert.sameValue(Temporal.TimeZone.prototype.getPreviousTransition.hasOwnProperty("prototype"),
+assert.sameValue(Temporal.ZonedDateTime.prototype.getTimeZoneTransition.hasOwnProperty("prototype"),
   false, "prototype property");

test/built-ins/Temporal/ZonedDateTime/prototype/getTimeZoneTransition/length.js

@@ -2,8 +2,8 @@
 // This code is governed by the BSD license found in the LICENSE file.
 
 /*---
-esid: sec-temporal.timezone.prototype.getprevioustransition
+esid: sec-temporal.zoneddatetime.prototype.gettimezonetransition
-description: Temporal.TimeZone.prototype.getPreviousTransition.length is 1
+description: Temporal.ZonedDateTime.prototype.getTimeZoneTransition.length is 0
 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
@@ -17,7 +17,7 @@ includes: [propertyHelper.js]
 features: [Temporal]
 ---*/
 
-verifyProperty(Temporal.TimeZone.prototype.getPreviousTransition, "length", {
+verifyProperty(Temporal.ZonedDateTime.prototype.getTimeZoneTransition, "length", {
   value: 1,
   writable: false,
   enumerable: false,

test/built-ins/Temporal/ZonedDateTime/prototype/getTimeZoneTransition/name.js

@@ -2,8 +2,8 @@
 // This code is governed by the BSD license found in the LICENSE file.
 
 /*---
-esid: sec-temporal.timezone.prototype.getprevioustransition
+esid: sec-temporal.zoneddatetime.prototype.gettimezonetransition
-description: Temporal.TimeZone.prototype.getPreviousTransition.name is "getPreviousTransition".
+description: Temporal.ZonedDateTime.prototype.getTimeZoneTransition.name is "getTimeZoneTransition".
 info: |
     Every built-in function object, including constructors, that is not identified as an anonymous
     function has a "name" property whose value is a String. Unless otherwise specified, this value
@@ -15,8 +15,8 @@ includes: [propertyHelper.js]
 features: [Temporal]
 ---*/
 
-verifyProperty(Temporal.TimeZone.prototype.getPreviousTransition, "name", {
+verifyProperty(Temporal.ZonedDateTime.prototype.getTimeZoneTransition, "name", {
-  value: "getPreviousTransition",
+  value: "getTimeZoneTransition",
   writable: false,
   enumerable: false,
   configurable: true,

test/built-ins/Temporal/ZonedDateTime/prototype/getTimeZoneTransition/not-a-constructor.js

@@ -2,9 +2,9 @@
 // This code is governed by the BSD license found in the LICENSE file.
 
 /*---
-esid: sec-temporal.timezone.prototype.getprevioustransition
+esid: sec-temporal.zoneddatetime.prototype.gettimezonetransition
 description: >
-  Temporal.TimeZone.prototype.getPreviousTransition does not implement [[Construct]], is not new-able
+  Temporal.ZonedDateTime.prototype.getTimeZoneTransition does not implement [[Construct]], is not new-able
 info: |
     Built-in function objects that are not identified as constructors do not implement the
     [[Construct]] internal method unless otherwise specified in the description of a particular
@@ -14,8 +14,8 @@ features: [Reflect.construct, Temporal]
 ---*/
 
 assert.throws(TypeError, () => {
-  new Temporal.TimeZone.prototype.getPreviousTransition();
+  new Temporal.ZonedDateTime.prototype.getTimeZoneTransition();
 }, "Calling as constructor");
 
-assert.sameValue(isConstructor(Temporal.TimeZone.prototype.getPreviousTransition), false,
+assert.sameValue(isConstructor(Temporal.ZonedDateTime.prototype.getTimeZoneTransition), false,
-  "isConstructor(Temporal.TimeZone.prototype.getPreviousTransition)");
+  "isConstructor(Temporal.ZonedDateTime.prototype.getTimeZoneTransition)");

test/built-ins/Temporal/ZonedDateTime/prototype/getTimeZoneTransition/prop-desc.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.zoneddatetime.prototype.gettimezonetransition
+description: The "getTimeZoneTransition" property of Temporal.ZonedDateTime.prototype
+includes: [propertyHelper.js]
+features: [Temporal]
+---*/
+
+assert.sameValue(
+  typeof Temporal.ZonedDateTime.prototype.getTimeZoneTransition,
+  "function",
+  "`typeof ZonedDateTime.prototype.getTimeZoneTransition` is `function`"
+);
+
+verifyProperty(Temporal.ZonedDateTime.prototype, "getTimeZoneTransition", {
+  writable: true,
+  enumerable: false,
+  configurable: true,
+});

test/intl402/Temporal/TimeZone/prototype/getNextTransition/subtract-second-and-nanosecond-from-last-transition.js

@@ -1,55 +0,0 @@
-// Copyright (C) 2022 André Bargull. All rights reserved.
-// This code is governed by the BSD license found in the LICENSE file.
-
-/*---
-esid: sec-temporal.timezone.prototype.getnexttransition
-description: >
-  Compute next transition when seconds resp. nanoseconds are subtracted from the last transition.
-features: [Temporal]
----*/
-
-// From <https://github.com/eggert/tz/blob/main/europe>:
-//
-// # Zone  NAME       STDOFF  RULES FORMAT  [UNTIL]
-// Zone  Europe/Paris 0:09:21 -     LMT     1891 Mar 15  0:01
-//                    0:09:21 -     PMT     1911 Mar 11  0:01 # Paris MT
-
-let tz = new Temporal.TimeZone("Europe/Paris");
-
-let zdt = new Temporal.PlainDateTime(1800, 1, 1).toZonedDateTime(tz);
-assert.sameValue(zdt.toString(), "1800-01-01T00:00:00+00:09[Europe/Paris]");
-assert.sameValue(zdt.offsetNanoseconds, (9 * 60 + 21) * 1_000_000_000);
-
-// Ensure the first transition was correctly computed.
-let first = tz.getNextTransition(zdt);
-assert.sameValue(first.toString(), "1911-03-10T23:50:39Z");
-assert.sameValue(new Temporal.ZonedDateTime(first.epochNanoseconds, tz).toString(),
-                 "1911-03-10T23:50:39+00:00[Europe/Paris]");
-
-let next;
-
-// Compute the next transition starting from the first transition minus 1s.
-let firstMinus1s = first.add({seconds: -1});
-assert.sameValue(firstMinus1s.toString(), "1911-03-10T23:50:38Z");
-assert.sameValue(new Temporal.ZonedDateTime(firstMinus1s.epochNanoseconds, tz).toString(),
-                 "1911-03-10T23:59:59+00:09[Europe/Paris]");
-assert.sameValue(new Temporal.ZonedDateTime(firstMinus1s.epochNanoseconds, tz).offsetNanoseconds,
-                 (9 * 60 + 21) * 1_000_000_000);
-
-next = tz.getNextTransition(firstMinus1s);
-assert.sameValue(next.toString(), "1911-03-10T23:50:39Z");
-assert.sameValue(new Temporal.ZonedDateTime(next.epochNanoseconds, tz).toString(),
-                 "1911-03-10T23:50:39+00:00[Europe/Paris]");
-
-// Compute the next transition starting from the first transition minus 1ns.
-let firstMinus1ns = first.add({nanoseconds: -1});
-assert.sameValue(firstMinus1ns.toString(), "1911-03-10T23:50:38.999999999Z");
-assert.sameValue(new Temporal.ZonedDateTime(firstMinus1ns.epochNanoseconds, tz).toString(),
-                 "1911-03-10T23:59:59.999999999+00:09[Europe/Paris]");
-assert.sameValue(new Temporal.ZonedDateTime(firstMinus1ns.epochNanoseconds, tz).offsetNanoseconds,
-                 (9 * 60 + 21) * 1_000_000_000);
-
-next = tz.getNextTransition(firstMinus1ns);
-assert.sameValue(next.toString(), "1911-03-10T23:50:39Z");
-assert.sameValue(new Temporal.ZonedDateTime(next.epochNanoseconds, tz).toString(),
-                 "1911-03-10T23:50:39+00:00[Europe/Paris]");

test/intl402/Temporal/TimeZone/prototype/getNextTransition/transition-at-instant-boundaries.js

@@ -1,26 +0,0 @@
-// Copyright (C) 2022 André Bargull. All rights reserved.
-// This code is governed by the BSD license found in the LICENSE file.
-
-/*---
-esid: sec-temporal.timezone.prototype.getnexttransition
-description: >
-  Test transitions at the instant boundaries.
-features: [Temporal, Intl-enumeration]
----*/
-
-const min = new Temporal.Instant(-86_40000_00000_00000_00000n);
-const max = new Temporal.Instant(86_40000_00000_00000_00000n);
-
-for (let id of Intl.supportedValuesOf("timeZone")) {
-  let tz = new Temporal.TimeZone(id);
-
-  // If there's any next transition, it should be after |min|.
-  let next = tz.getNextTransition(min);
-  if (next) {
-    assert(next.epochNanoseconds > min.epochNanoseconds);
-  }
-
-  // There shouldn't be any next transition after |max|.
-  next = tz.getNextTransition(max);
-  assert.sameValue(next, null);
-}

test/intl402/Temporal/TimeZone/prototype/getPreviousTransition/nanoseconds-subtracted-or-added-at-dst-transition.js

@@ -1,24 +0,0 @@
-// Copyright (C) 2022 André Bargull. All rights reserved.
-// This code is governed by the BSD license found in the LICENSE file.
-
-/*---
-esid: sec-temporal.timezone.prototype.getprevioustransition
-description: >
-  Test previous transition when nanoseconds are subtracted resp. added to the DST transition.
-features: [Temporal]
----*/
-
-let tz = new Temporal.TimeZone("Europe/Berlin");
-let p = Temporal.Instant.from("2021-03-28T01:00:00Z");
-
-assert.sameValue(tz.getPreviousTransition(p.add({nanoseconds: -1})).toString(),
-                 "2020-10-25T01:00:00Z",
-                 "DST transition minus one nanosecond");
-
-assert.sameValue(tz.getPreviousTransition(p).toString(),
-                 "2020-10-25T01:00:00Z",
-                 "DST transition");
-
-assert.sameValue(tz.getPreviousTransition(p.add({nanoseconds: +1})).toString(),
-                 "2021-03-28T01:00:00Z",
-                 "DST transition plus one nanosecond");

test/intl402/Temporal/TimeZone/prototype/getPreviousTransition/transition-at-instant-boundaries.js

@@ -1,26 +0,0 @@
-// Copyright (C) 2022 André Bargull. All rights reserved.
-// This code is governed by the BSD license found in the LICENSE file.
-
-/*---
-esid: sec-temporal.timezone.prototype.getprevioustransition
-description: >
-  Test transitions at the instant boundaries.
-features: [Temporal, Intl-enumeration]
----*/
-
-const min = new Temporal.Instant(-86_40000_00000_00000_00000n);
-const max = new Temporal.Instant(86_40000_00000_00000_00000n);
-
-for (let id of Intl.supportedValuesOf("timeZone")) {
-  let tz = new Temporal.TimeZone(id);
-
-  // If there's any previous transition, it should be before |max|.
-  let prev = tz.getPreviousTransition(max);
-  if (prev) {
-    assert(prev.epochNanoseconds < max.epochNanoseconds);
-  }
-
-  // There shouldn't be any previous transition before |min|.
-  prev = tz.getPreviousTransition(min);
-  assert.sameValue(prev, null);
-}

test/intl402/Temporal/ZonedDateTime/prototype/getTimeZoneTransition/nanoseconds-subtracted-or-added-at-dst-transition.js

@@ -0,0 +1,23 @@
+// Copyright (C) 2022 André Bargull. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+esid: sec-temporal.zoneddatetime.prototype.gettimezonetransition
+description: >
+  Test previous transition when nanoseconds are subtracted resp. added to the DST transition.
+features: [Temporal]
+---*/
+
+const dt = Temporal.ZonedDateTime.from("2021-03-28T01:00:00Z[Europe/Berlin]");
+
+assert.sameValue(dt.add({nanoseconds: -1}).getTimeZoneTransition("previous").toString(),
+                 "2020-10-25T02:00:00+01:00[Europe/Berlin]",
+                 "DST transition minus one nanosecond");
+
+assert.sameValue(dt.getTimeZoneTransition("previous").toString(),
+                 "2020-10-25T02:00:00+01:00[Europe/Berlin]",
+                 "DST transition");
+
+assert.sameValue(dt.add({nanoseconds: +1}).getTimeZoneTransition("previous").toString(),
+                 "2021-03-28T03:00:00+02:00[Europe/Berlin]",
+                 "DST transition plus one nanosecond");

test/intl402/Temporal/ZonedDateTime/prototype/getTimeZoneTransition/subtract-second-and-nanosecond-from-last-transition.js

@@ -0,0 +1,41 @@
+// Copyright (C) 2022 André Bargull. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+esid: sec-temporal.zoneddatetime.prototype.gettimezonetransition
+description: >
+  Compute next transition when seconds resp. nanoseconds are subtracted from the last transition.
+features: [Temporal]
+---*/
+
+// From <https://github.com/eggert/tz/blob/main/europe>:
+//
+// # Zone  NAME       STDOFF  RULES FORMAT  [UNTIL]
+// Zone  Europe/Paris 0:09:21 -     LMT     1891 Mar 15  0:01
+//                    0:09:21 -     PMT     1911 Mar 11  0:01 # Paris MT
+
+const zdt = new Temporal.PlainDateTime(1800, 1, 1).toZonedDateTime("Europe/Paris");
+assert.sameValue(zdt.toString(), "1800-01-01T00:00:00+00:09[Europe/Paris]");
+assert.sameValue(zdt.offsetNanoseconds, (9 * 60 + 21) * 1_000_000_000);
+
+// Ensure the first transition was correctly computed.
+const first = zdt.getTimeZoneTransition("next");
+assert.sameValue(first.toString(), "1911-03-10T23:50:39+00:00[Europe/Paris]");
+
+let next;
+
+// Compute the next transition starting from the first transition minus 1s.
+const firstMinus1s = first.add({seconds: -1});
+assert.sameValue(firstMinus1s.toString(), "1911-03-10T23:59:59+00:09[Europe/Paris]");
+assert.sameValue(firstMinus1s.offsetNanoseconds, (9 * 60 + 21) * 1_000_000_000);
+
+next = firstMinus1s.getTimeZoneTransition("next");
+assert.sameValue(next.toString(), "1911-03-10T23:50:39+00:00[Europe/Paris]");
+
+// Compute the next transition starting from the first transition minus 1ns.
+const firstMinus1ns = first.add({nanoseconds: -1});
+assert.sameValue(firstMinus1ns.toString(), "1911-03-10T23:59:59.999999999+00:09[Europe/Paris]");
+assert.sameValue(firstMinus1ns.offsetNanoseconds, (9 * 60 + 21) * 1_000_000_000);
+
+next = firstMinus1ns.getTimeZoneTransition("next");
+assert.sameValue(next.toString(), "1911-03-10T23:50:39+00:00[Europe/Paris]");

test/intl402/Temporal/ZonedDateTime/prototype/getTimeZoneTransition/transition-at-instant-boundaries.js

@@ -0,0 +1,30 @@
+// Copyright (C) 2022 André Bargull. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+esid: sec-temporal.zoneddatetime.prototype.gettimezonetransition
+description: >
+  Test transitions at the instant boundaries.
+features: [Temporal, Intl-enumeration]
+---*/
+
+for (let id of Intl.supportedValuesOf("timeZone")) {
+  const min = new Temporal.ZonedDateTime(-86_40000_00000_00000_00000n, id);
+  const max = new Temporal.ZonedDateTime(86_40000_00000_00000_00000n, id);
+
+  const next = min.getTimeZoneTransition("next");
+  if (next) {
+    assert(next.epochNanoseconds > min.epochNanoseconds,
+      "If there's any next transition, it should be after |min|");
+  }
+
+  const prev = max.getTimeZoneTransition("previous");
+  if (prev) {
+    assert(prev.epochNanoseconds < max.epochNanoseconds,
+      "If there's any previous transition, it should be before |max|");
+  }
+
+  assert.sameValue(max.getTimeZoneTransition("next"), null, "There shouldn't be any next transition after |max|");
+  assert.sameValue(min.getTimeZoneTransition("previous"), null,
+    "There shouldn't be any previous transition before |min|");
+}