Migrate to new timezone database - Attempt #2 (#83)

* fix windows integration testing

* add timezone abbr to offset

* convert func takes datetime parts instead of millis from epch

* remove old database files

* add toString and correct final/initial for span

* replace default provider with embedded provider

* update tests

* add packages to pubspec

* add timezone generation tool

* replace default provider with embedded

* add java testing

* fix dst bug, add dst and abbr to java provider

* Add CI

* ignore unsued

* remove unused func

* rename DSTRules

* nits

* remove base provider

.github/workflows/sugar_integration_test.yaml

@@ -30,7 +30,7 @@ jobs:
       - uses: actions/checkout@v4
       - uses: subosito/[email protected]
       - run: dart pub get
-      - run: dart run coverage:test_with_coverage test ./integration_test/
+      - run: dart run coverage:test_with_coverage --test  .\integration_test\src\time\zone\platform\platform_provider_test.dart
       - uses: codecov/codecov-action@v5
         with:
           files: ./sugar/coverage/lcov.info
@@ -87,4 +87,4 @@ jobs:
       - run: ./integration_test/src/time/zone/platform/platform_provider_test_browser.sh
       - uses: codecov/codecov-action@v5
         with:
-          files: ./sugar/coverage/lcov.info
+          files: ./sugar/coverage/lcov.info

.github/workflows/sugar_unit_test.yaml

@@ -34,12 +34,23 @@ jobs:
     steps:
       - uses: actions/checkout@v4
       - uses: subosito/[email protected]
+      - name: Install Node
+        uses: actions/setup-node@v4
+        with:
+          node-version: "20"
+      - name: Install Java
+        uses: actions/setup-java@v4
+        with:
+          distribution: "adopt"
+          java-version: "11.0.26+4"
       - run: dart pub get
       - run: dart analyze --fatal-warnings
+      - run: dart format . --set-exit-if-changed --output none
+      - run: dart run tool/generate_timezones.dart
       - run: dart run coverage:test_with_coverage
       - run: sudo apt-get update -y
       - run: sudo apt-get install -y lcov
-      - run: lcov --remove ./coverage/lcov.info '**.g.dart' -o ./coverage/lcov.info
+      - run: lcov --remove ./coverage/lcov.info '**.g.dart' -o ./coverage/lcov.info --ignore-errors unused
       - uses: codecov/codecov-action@v5
         with:
-          files: ./sugar/coverage/lcov.info
+          files: ./sugar/coverage/lcov.info

sugar/integration_test/src/time/zone/platform/platform_provider_test.dart

@@ -4,15 +4,15 @@ import 'package:test/test.dart';
 /// These tests should be ran using the shell/bat scripts in the same folder.
 void main() {
   test('defaultPlatformTimezoneProvider() return current timezone', () {
-    final timezones = DefaultTimezoneProvider();
+    final timezones = EmbeddedTimezoneProvider();
     final timezone = defaultPlatformTimezoneProvider();
 
     expect(timezones.containsKey(timezone), true);
     expect(timezone, isNot('Factory'));
   }, testOn: 'windows');
 
   test('defaultPlatformTimezoneProvider() return current timezone', () {
-    final timezones = DefaultTimezoneProvider();
+    final timezones = EmbeddedTimezoneProvider();
     final timezone = defaultPlatformTimezoneProvider();
 
     expect(timezones.containsKey(timezone), true);
@@ -21,15 +21,15 @@ void main() {
 
   group('posix', () {
     test('defaultPlatformTimezoneProvider() known TZ environment variable', () {
-      final timezones = DefaultTimezoneProvider();
+      final timezones = EmbeddedTimezoneProvider();
       final timezone = defaultPlatformTimezoneProvider();
 
       expect(timezones.containsKey(timezone), true);
       expect(timezone, 'Mexico/BajaSur');
     });
 
     test('defaultPlatformTimezoneProvider() unknown TZ environment variable', () {
-      final timezones = DefaultTimezoneProvider();
+      final timezones = EmbeddedTimezoneProvider();
       final timezone = defaultPlatformTimezoneProvider();
 
       expect(timezones.containsKey(timezone), true);

sugar/lib/src/time/offset.dart

@@ -241,7 +241,8 @@ sealed class Offset with Orderable<Offset> {
   @override
   @nonVirtual
   @useResult
-  bool operator ==(Object other) => // ignore: hash_and_equals, invalid_override_of_non_virtual_member
+  // ignore: hash_and_equals, invalid_override_of_non_virtual_member
+  bool operator ==(Object other) =>
       identical(this, other) ||
       other is Offset && (runtimeType == _Offset || runtimeType == LiteralOffset) && compareTo(other) == 0;
 
@@ -268,7 +269,17 @@ sealed class Offset with Orderable<Offset> {
   /// print(Offset(1, 2, 3)); // '+01:02:03'
   /// ```
   @override
-  @mustBeOverridden
   @useResult
   String toString();
+
+  /// Returns the offset represented as a timezone abbreviation, adhering to
+  /// the ISO 8601 standard.
+  ///
+  /// See: https://en.wikipedia.org/wiki/ISO_8601#Time_offsets_from_UTC
+  ///
+  /// Example:
+  /// ```dart
+  /// print(Offset(1).toTimezoneAbbreviation()); // '+0100'
+  /// ```
+  String toTimezoneAbbreviation() => formatTimezoneAbbreviation(_microseconds);
 }

sugar/lib/src/time/offsets.dart

@@ -31,6 +31,25 @@ String format(int microseconds) {
   return '$sign$hours:$minutes$suffix';
 }
 
+/// Format a duration of microseconds into a timezone abbreviation.
+///
+/// ```dart
+/// print(toTimezoneAbbreviation(0)); // '+0000'
+/// print(toTimezoneAbbreviation(1)); // '+0100'
+/// print(toTimezoneAbbreviation(-1)); // '-0100'
+/// ```
+String formatTimezoneAbbreviation(int microseconds) {
+  var value = microseconds ~/ 1000 ~/ 1000 ~/ 60;
+  final sign = value.isNegative ? '-' : '+';
+  value = value.abs();
+  final minute = value % 60;
+  value ~/= 60;
+  final hour = value % 60;
+  final hours = hour.toString().padLeft(2, '0');
+  final minutes = minute.toString().padLeft(2, '0');
+  return '$sign$hours$minutes';
+}
+
 const _allowed = '''
 The following offset formats are accepted:
   * Z - for UTC
@@ -102,7 +121,9 @@ final class _Offset extends Offset {
       return parsed;
     }
 
-    late final int hour, minute, second; // ignore: avoid_multiple_declarations_per_line
+    late final int hour;
+    late final int minute;
+    late final int second; // ignore: avoid_multiple_declarations_per_line
     switch (offset.length) {
       case 2:
         offset = '${offset[0]}0${offset[1]}';

sugar/lib/src/time/zone/factory_timezone.dart

@@ -0,0 +1,36 @@
+import 'package:sugar/src/time/zone/timezone.dart';
+import 'package:sugar/src/time/zone/timezone_span.dart';
+import 'package:sugar/time.dart';
+
+/// A timezone which is used when the platform's timezone could not be retrieved.
+class FactoryTimezone extends Timezone {
+  /// Creates a new instance of [FactoryTimezone].
+  ///
+  /// This constructor calls the super constructor with the string 'Factory'.
+  const FactoryTimezone() : super.from('Factory');
+
+  @override
+  (EpochMicroseconds, TimezoneSpan) convert(
+    int year, [
+    int month = 1,
+    int day = 1,
+    int hour = 0,
+    int minute = 0,
+    int second = 0,
+    int millisecond = 0,
+    int microsecond = 0,
+  ]) => (0, span(at: 0));
+
+  @override
+  TimezoneSpan span({required EpochMicroseconds at}) => _FactoryTimezoneSpan(offset: Offset());
+}
+
+class _FactoryTimezoneSpan extends TimezoneSpan {
+  @override
+  EpochMicroseconds get start => TimezoneSpan.range.min.value;
+  @override
+  EpochMicroseconds get end => TimezoneSpan.range.max.value;
+
+  /// Creates a new instance of [_FactoryTimezoneSpan].
+  _FactoryTimezoneSpan({required super.offset, super.abbreviation = '+0000', super.dst = false});
+}