Update to latest lints, require Dart 2.17, fix deprecation

.github/workflows/dart.yml

@@ -47,7 +47,7 @@ jobs:
       matrix:
         # Test against the SDK lower-bound defined in pubspec.yaml and dev.
         os: [ubuntu-latest]
-        sdk: [2.12.0, dev]
+        sdk: [2.17.0, dev]
     steps:
       - uses: actions/checkout@v2
       - uses: dart-lang/setup-dart@v1.0

CHANGELOG.md

@@ -2,6 +2,7 @@
 
   * Expose `TreeIterator` for iterating `TreeSet` instead of using
     `BidirectionalIterator`.
+  * Require Dart 2.17
 
 #### 3.1.0 - 2022-05-03
 

analysis_options.yaml

@@ -1,163 +1,40 @@
+# https://dart.dev/guides/language/analysis-options
+include: package:lints/recommended.yaml
+
 analyzer:
   errors:
-    # treat missing required parameters as a warning (not a hint)
-    missing_required_param: warning
-    # treat missing returns as a warning (not a hint)
-    missing_return: warning
-    # allow having TODOs in the code
-    todo: ignore
-    # Ignore analyzer hints for updating pubspecs when using Future or
-    # Stream and not importing dart:async
-    # Please see https://github.com/flutter/flutter/pull/24528 for details.
-    sdk_version_async_exported_from_core: ignore
+    # TODO(kevmoo): see https://github.com/dart-lang/linter/issues/3844
+    null_check_on_nullable_type_parameter: ignore
 
 linter:
   rules:
-    # these rules are documented on and in the same order as
-    # the Dart Lint rules page to make maintenance easier
-    # https://github.com/dart-lang/linter/blob/master/example/all.yaml
     - always_declare_return_types
-    # ENABLE - always_put_control_body_on_new_line
     - always_put_required_named_parameters_first
-    - always_require_non_null_named_parameters
-    # ENABLE - always_specify_types
-    - annotate_overrides
-    # - avoid_annotating_with_dynamic # conflicts with always_specify_types
-    # - avoid_as # conflicts with NNBD
     - avoid_bool_literals_in_conditional_expressions
-    # - avoid_catches_without_on_clauses # we do this commonly
-    # - avoid_catching_errors # we do this commonly
     - avoid_classes_with_only_static_members
-    # - avoid_double_and_int_checks # only useful when targeting JS runtime
-    - avoid_empty_else
     - avoid_field_initializers_in_const_classes
-    - avoid_function_literals_in_foreach_calls
-    # - avoid_implementing_value_types # not yet tested
-    - avoid_init_to_null
-    # - avoid_js_rounded_ints # only useful when targeting JS runtime
-    - avoid_null_checks_in_equality_operators
-    # - avoid_positional_boolean_parameters # not yet tested
-    # - avoid_private_typedef_functions # we prefer having typedef (discussion in https://github.com/flutter/flutter/pull/16356)
-    - avoid_relative_lib_imports
-    - avoid_renaming_method_parameters
-    - avoid_return_types_on_setters
-    # - avoid_returning_null # there are plenty of valid reasons to return null
-    # - avoid_returning_null_for_future # not yet tested
-    - avoid_returning_null_for_void
-    # - avoid_returning_this # there are plenty of valid reasons to return this
-    # - avoid_setters_without_getters # not yet tested
-    # - avoid_shadowing_type_parameters # not yet tested
-    # - avoid_single_cascade_in_expression_statements # not yet tested
     - avoid_slow_async_io
-    - avoid_types_as_parameter_names
-    # - avoid_types_on_closure_parameters # conflicts with always_specify_types
     - avoid_unused_constructor_parameters
     - avoid_void_async
-    - await_only_futures
-    - camel_case_types
     - cancel_subscriptions
-    # - cascade_invocations # not yet tested
-    # - close_sinks # not reliable enough
-    # - comment_references # blocked on https://github.com/flutter/flutter/issues/20765
-    # - constant_identifier_names # needs an opt-out https://github.com/dart-lang/linter/issues/204
-    - control_flow_in_finally
-    - curly_braces_in_flow_control_structures
-    # - diagnostic_describe_all_properties # not yet tested
     - directives_ordering
-    - empty_catches
-    - empty_constructor_bodies
-    - empty_statements
-    # - file_names # not yet tested
     - flutter_style_todos
-    - hash_and_equals
-    - implementation_imports
-    - iterable_contains_unrelated_type
-    # - join_return_with_assignment # not yet tested
-    - library_names
-    - library_prefixes
-    # - lines_longer_than_80_chars # not yet tested
-    - list_remove_unrelated_type
-    # - literal_only_boolean_expressions # too many false positives: https://github.com/dart-lang/sdk/issues/34181
     - no_adjacent_strings_in_list
-    - no_duplicate_case_values
-    - non_constant_identifier_names
-    # - null_closures  # not yet tested
-    # - omit_local_variable_types # opposite of always_specify_types
-    # - one_member_abstracts # too many false positives
-    # - only_throw_errors # https://github.com/flutter/flutter/issues/5792
-    - overridden_fields
     - package_api_docs
-    - package_names
-    - package_prefixed_library_names
-    # - parameter_assignments # we do this commonly
-    - prefer_adjacent_string_concatenation
     - prefer_asserts_in_initializer_lists
-    # - prefer_asserts_with_message # not yet tested
-    # ENABLE - prefer_collection_literals
-    - prefer_conditional_assignment
     - prefer_const_constructors
     - prefer_const_constructors_in_immutables
     - prefer_const_declarations
     - prefer_const_literals_to_create_immutables
-    # - prefer_constructors_over_static_methods # not yet tested
-    - prefer_contains
-    # - prefer_double_quotes # opposite of prefer_single_quotes
-    - prefer_equal_for_default_values
-    # - prefer_expression_function_bodies # conflicts with https://github.com/flutter/flutter/wiki/Style-guide-for-Flutter-repo#consider-using--for-short-functions-and-methods
-    - prefer_final_fields
     - prefer_final_in_for_each
-    # ENABLE - prefer_final_locals
-    # - prefer_for_elements_to_map_fromIterable # not yet tested
     - prefer_foreach
-    # - prefer_function_declarations_over_variables # not yet tested
-    - prefer_generic_function_type_aliases
     - prefer_if_elements_to_conditional_expressions
-    - prefer_if_null_operators
-    - prefer_initializing_formals
-    - prefer_inlined_adds
-    # - prefer_int_literals # not yet tested
-    # - prefer_interpolation_to_compose_strings # not yet tested
-    - prefer_is_empty
-    - prefer_is_not_empty
-    - prefer_iterable_whereType
-    # - prefer_mixin # https://github.com/dart-lang/language/issues/32
-    # - prefer_null_aware_operators # disable until NNBD, see https://github.com/flutter/flutter/pull/32711#issuecomment-492930932
     - prefer_single_quotes
-    - prefer_spread_collections
-    - prefer_typing_uninitialized_variables
-    # ENABLE - prefer_void_to_null
-    - provide_deprecation_message
-    # - public_member_api_docs # enabled on a case-by-case basis; see e.g. packages/analysis_options.yaml
-    - recursive_getters
-    - slash_for_doc_comments
-    # - sort_child_properties_last # not yet tested
     - sort_constructors_first
     - sort_pub_dependencies
     - sort_unnamed_constructors_first
     - test_types_in_equals
     - throw_in_finally
-    # - type_annotate_public_apis # subset of always_specify_types
-    - type_init_formals
-    # - unawaited_futures # too many false positives
-    # - unnecessary_await_in_return # not yet tested
-    - unnecessary_brace_in_string_interps
-    - unnecessary_const
-    - unnecessary_getters_setters
-    # - unnecessary_lambdas # has false positives: https://github.com/dart-lang/linter/issues/498
-    - unnecessary_new
-    - unnecessary_null_aware_assignments
-    - unnecessary_null_in_if_null_operators
-    - unnecessary_overrides
     - unnecessary_parenthesis
     - unnecessary_statements
-    - unnecessary_this
-    - unrelated_type_equality_checks
-    # - unsafe_html # not yet tested
-    - use_full_hex_values_for_flutter_colors
-    # - use_function_type_syntax_for_parameters # not yet tested
-    - use_rethrow_when_possible
-    # - use_setters_to_change_properties # not yet tested
-    # - use_string_buffers # has false positives: https://github.com/dart-lang/sdk/issues/34182
-    # - use_to_and_as_if_applicable # has false positives, so we prefer to catch this by code-review
-    - valid_regexps
-    # - void_checks # not yet tested
+    - use_super_parameters

lib/pattern.dart

@@ -42,7 +42,7 @@ class _MultiPattern extends Pattern {
 
   @override
   Iterable<Match> allMatches(String str, [int start = 0]) {
-    final _allMatches = <Match>[];
+    final allMatches = <Match>[];
     for (final pattern in include) {
       var matches = pattern.allMatches(str, start);
       if (_hasMatch(matches)) {
@@ -53,10 +53,10 @@ class _MultiPattern extends Pattern {
             }
           }
         }
-        _allMatches.addAll(matches);
+        allMatches.addAll(matches);
       }
     }
-    return _allMatches;
+    return allMatches;
   }
 
   @override

lib/src/async/concat.dart

@@ -40,8 +40,8 @@ class _ConcatStream<T> extends Stream<T> {
   final Iterable<Stream<T>> _streams;
 
   @override
-  StreamSubscription<T> listen(void onData(T data)?,
-      {Function? onError, void onDone()?, bool? cancelOnError}) {
+  StreamSubscription<T> listen(void Function(T data)? onData,
+      {Function? onError, void Function()? onDone, bool? cancelOnError}) {
     cancelOnError = true == cancelOnError;
     StreamSubscription<T>? currentSubscription;
     StreamController<T>? controller;

lib/src/async/countdown_timer.dart

@@ -35,7 +35,7 @@ class CountdownTimer extends Stream<CountdownTimer> {
     _stopwatch.start();
   }
 
-  static const _THRESHOLD_MS = 4;
+  static const _thresholdMS = 4;
 
   final Duration _duration;
   final Stopwatch _stopwatch;
@@ -46,8 +46,11 @@ class CountdownTimer extends Stream<CountdownTimer> {
   late final Timer _timer;
 
   @override
-  StreamSubscription<CountdownTimer> listen(void onData(CountdownTimer event)?,
-          {Function? onError, void onDone()?, bool? cancelOnError}) =>
+  StreamSubscription<CountdownTimer> listen(
+          void Function(CountdownTimer event)? onData,
+          {Function? onError,
+          void Function()? onDone,
+          bool? cancelOnError}) =>
       _controller.stream.listen(onData, onError: onError, onDone: onDone);
 
   Duration get elapsed => _stopwatch.elapsed;
@@ -66,7 +69,7 @@ class CountdownTimer extends Stream<CountdownTimer> {
     var t = remaining;
     _controller.add(this);
     // timers may have a 4ms resolution
-    if (t.inMilliseconds < _THRESHOLD_MS) {
+    if (t.inMilliseconds < _thresholdMS) {
       cancel();
     }
   }

lib/src/async/future_stream.dart

@@ -71,8 +71,8 @@ class FutureStream<T> extends Stream<T> {
   }
 
   @override
-  StreamSubscription<T> listen(void onData(T event)?,
-      {Function? onError, void onDone()?, bool? cancelOnError}) {
+  StreamSubscription<T> listen(void Function(T event)? onData,
+      {Function? onError, void Function()? onDone, bool? cancelOnError}) {
     return _controller!.stream.listen(onData,
         onError: onError, onDone: onDone, cancelOnError: cancelOnError);
   }

lib/src/async/metronome.dart

@@ -85,8 +85,8 @@ class Metronome extends Stream<DateTime> {
   bool get isBroadcast => true;
 
   @override
-  StreamSubscription<DateTime> listen(void onData(DateTime event)?,
-          {Function? onError, void onDone()?, bool? cancelOnError}) =>
+  StreamSubscription<DateTime> listen(void Function(DateTime event)? onData,
+          {Function? onError, void Function()? onDone, bool? cancelOnError}) =>
       _controller.stream.listen(onData,
           onError: onError, onDone: onDone, cancelOnError: cancelOnError);
 

lib/src/async/stream_buffer.dart

@@ -135,7 +135,7 @@ class StreamBuffer<T> implements StreamConsumer<List<T>> {
     _sub?.cancel();
     _currentStream = stream;
 
-    final streamDone = Completer<Null>();
+    final streamDone = Completer<void>();
     _sub = stream.listen((items) {
       _chunks.addAll(items);
       _counter += items.length;

lib/src/async/stream_router.dart

@@ -46,7 +46,7 @@ class StreamRouter<T> {
 
   /// Events that match [predicate] are sent to the stream created by this
   /// method, and not sent to any other router streams.
-  Stream<T> route(bool predicate(T event)) {
+  Stream<T> route(bool Function(T event) predicate) {
     var controller = StreamController<T>.broadcast();
     _routes.add(_Route(predicate, controller));
     return controller.stream;
@@ -72,11 +72,9 @@ class StreamRouter<T> {
   }
 }
 
-typedef _Predicate<T> = bool Function(T event);
-
 class _Route<T> {
   _Route(this.predicate, this.controller);
 
-  final _Predicate<T> predicate;
+  final bool Function(T event) predicate;
   final StreamController<T> controller;
 }

lib/src/collection/bimap.dart

@@ -74,7 +74,7 @@ class HashBiMap<K, V> implements BiMap<K, V> {
   bool containsValue(Object? value) => _inverse.containsKey(value);
 
   @override
-  void forEach(void f(K key, V value)) => _map.forEach(f);
+  void forEach(void Function(K key, V value) f) => _map.forEach(f);
 
   @override
   bool get isEmpty => _map.isEmpty;
@@ -111,11 +111,12 @@ class HashBiMap<K, V> implements BiMap<K, V> {
   Iterable<MapEntry<K, V>> get entries => _map.entries;
 
   @override
-  Map<K2, V2> map<K2, V2>(MapEntry<K2, V2> transform(K key, V value)) =>
+  Map<K2, V2> map<K2, V2>(
+          MapEntry<K2, V2> Function(K key, V value) transform) =>
       _map.map(transform);
 
   @override
-  V putIfAbsent(K key, V ifAbsent()) {
+  V putIfAbsent(K key, V Function() ifAbsent) {
     if (containsKey(key)) {
       return _map[key]!;
     }
@@ -129,13 +130,13 @@ class HashBiMap<K, V> implements BiMap<K, V> {
   }
 
   @override
-  void removeWhere(bool test(K key, V value)) {
+  void removeWhere(bool Function(K key, V value) test) {
     _inverse.removeWhere((v, k) => test(k, v));
     _map.removeWhere(test);
   }
 
   @override
-  V update(K key, V update(V value), {V ifAbsent()?}) {
+  V update(K key, V Function(V value) update, {V Function()? ifAbsent}) {
     var value = _map[key];
     if (value != null) {
       return _add(key, update(value), true);
@@ -148,7 +149,7 @@ class HashBiMap<K, V> implements BiMap<K, V> {
   }
 
   @override
-  void updateAll(V update(K key, V value)) {
+  void updateAll(V Function(K key, V value) update) {
     for (final key in keys) {
       _add(key, update(key, _map[key]!), true);
     }