flutter - Dart 短绒 : enforce type annotation everywhere except lambdas

Question

我希望我的 linter 提示除了 lambda 之外的所有地方都缺少类型注释，因为在我看来，它会恶化代码的可读性而几乎没有什么优势。

例如，这些语句应该引发警告/提示:

const s = 'my string'; // Specify type annotation.
foo() => 'foo';        // Missing return type for foo.
List bar() =>          // Specify type annotation.
    ['bar', 'baz'];    // Specify type annotation.

这不应该:

<String>['qux', 'quux', 'corge']
    .map((s) => s.toUpperCase());

我认为这些是我的 analysis_option.yaml 中的相关规则:

analyzer:
  strong-mode:
    implicit-dynamic: false
errors:
    missing_required_param: warning
    missing_return: warning
    [...]

和

linter:
  rules:
    [...]
    - always_specify_types
    [...]

如果需要，这是完整的 analysis_option.yaml

# Specify analysis options.
#
# Until there are meta linter rules, each desired lint must be explicitly enabled.
# See: https://github.com/dart-lang/linter/issues/288
#
# For a list of lints, see: http://dart-lang.github.io/linter/lints/
# See the configuration guide for more
# https://github.com/dart-lang/sdk/tree/master/pkg/analyzer#configuring-the-analyzer
#
# There are other similar analysis options files in the flutter repos,
# which should be kept in sync with this file:
#
#   - analysis_options.yaml (this file)
#   - packages/flutter/lib/analysis_options_user.yaml
#   - https://github.com/flutter/plugins/blob/master/analysis_options.yaml
#   - https://github.com/flutter/engine/blob/master/analysis_options.yaml
#
# This file contains the analysis options used by Flutter tools, such as IntelliJ,
# Android Studio, and the `flutter analyze` command.

analyzer:
  strong-mode:
    implicit-dynamic: false
  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: warning
    # 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
  exclude:
    - "bin/cache/**"
    # the following two are relative to the stocks example and the flutter package respectively
    # see https://github.com/dart-lang/sdk/issues/28463
    - "lib/i18n/stock_messages_*.dart"
    - "lib/src/http/**"

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
#    - always_put_control_body_on_new_line
    # - always_put_required_named_parameters_first # we prefer having parameters in the same order as fields https://github.com/flutter/flutter/issues/10219
    - always_require_non_null_named_parameters
    - always_specify_types
    - annotate_overrides
    # - avoid_annotating_with_dynamic # conflicts with always_specify_types
    - avoid_as
    - 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_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 # not yet tested
    # - 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
    # - invariant_booleans # too many false positives: https://github.com/dart-lang/linter/issues/811
    - 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
    - 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 # not yet tested
    - 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 # not yet tested
    - 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
    - prefer_void_to_null
    # - provide_deprecation_message # not yet tested
    # - 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

Answer 1

您正在寻找 avoid_type_checks_on_closure_parameters Lint 。

从文档:

AVOID annotating types for function expression parameters.

Annotating types for function expression parameters is usually unnecessary because the parameter types can almost always be inferred from the context, thus making the practice redundant.

BAD:

var names = people.map((Person person) => person.name);

GOOD:

var names = people.map((person) => person.name);

编辑:看起来有 an open issue for this .如果您遇到此问题，请点赞该问题并发表评论，因为团队在确定错误修复的优先级时会将这些考虑在内。