Validate rules for NNBD and other recent language changes

[bwilkerson]

This is a tracking issue. The following is a list of the current lint rules. They should be checked off when they have been validated.

• always_declare_return_types
• always_put_control_body_on_new_line
• always_put_required_named_parameters_first
• always_require_non_null_named_parameters
  • This will be obsolete under NNBD
• always_specify_types
• annotate_overrides
• avoid_annotating_with_dynamic
• avoid_as
  • This will be obsolete under NNBD
• avoid_bool_literals_in_conditional_expressions
• avoid_catches_without_on_clauses
• avoid_catching_errors
• avoid_classes_with_only_static_members
• avoid_double_and_int_checks
• avoid_empty_else
• avoid_equals_and_hash_code_on_mutable_classes
• avoid_field_initializers_in_const_classes
• avoid_function_literals_in_foreach_calls
• avoid_implementing_value_types
• avoid_init_to_null
• avoid_js_rounded_ints
• avoid_null_checks_in_equality_operators
  • This will be obsolete under NNBD
  • Might want a lint to prevent using Object? for the parameter
• avoid_positional_boolean_parameters
• avoid_print
• avoid_private_typedef_functions
• avoid_redundant_argument_values
• avoid_relative_lib_imports
• avoid_renaming_method_parameters
• avoid_return_types_on_setters
• avoid_returning_null
  • This will be obsolete under NNBD
• avoid_returning_null_for_future
  • This will be obsolete under NNBD
• avoid_returning_null_for_void
• avoid_returning_this
• avoid_setters_without_getters
• avoid_shadowing_type_parameters
• avoid_single_cascade_in_expression_statements
• avoid_slow_async_io
• avoid_types_as_parameter_names
• avoid_types_on_closure_parameters
• avoid_unnecessary_containers
• avoid_unused_constructor_parameters
• avoid_void_async
• avoid_web_libraries_in_flutter
• await_only_futures
• camel_case_extensions
• camel_case_types
• cancel_subscriptions
• cascade_invocations
• close_sinks
• comment_references
• constant_identifier_names
• control_flow_in_finally
• curly_braces_in_flow_control_structures
• diagnostic_describe_all_properties
• directives_ordering
• empty_catches
• empty_constructor_bodies
• empty_statements
• file_names
• flutter_style_todos
• hash_and_equals
• implementation_imports
• invariant_booleans
• iterable_contains_unrelated_type
• join_return_with_assignment
• library_names
• library_prefixes
• lines_longer_than_80_chars
• list_remove_unrelated_type
• literal_only_boolean_expressions
• no_adjacent_strings_in_list
• no_duplicate_case_values
• no_logic_in_create_state
• non_constant_identifier_names
• null_closures
  • This will be obsolete under NNBD
• omit_local_variable_types
• one_member_abstracts
• only_throw_errors
• overridden_fields
• package_api_docs
• package_prefixed_library_names
• parameter_assignments
• prefer_adjacent_string_concatenation
• prefer_asserts_in_initializer_lists
• prefer_asserts_with_message
• prefer_bool_in_asserts
  • Deprecated as of 2.0.
• 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
• prefer_contains
• prefer_double_quotes
• prefer_equal_for_default_values
• prefer_expression_function_bodies
• prefer_final_fields
• prefer_final_in_for_each
• prefer_final_locals
• prefer_for_elements_to_map_fromIterable
• prefer_foreach
• prefer_function_declarations_over_variables
• prefer_generic_function_type_aliases
• prefer_if_elements_to_conditional_expressions
• prefer_if_null_operators
• prefer_initializing_formals
• prefer_inlined_adds
• prefer_int_literals
• prefer_interpolation_to_compose_strings
• prefer_is_empty
• prefer_is_not_empty
• prefer_is_not_operator
• prefer_iterable_whereType
• prefer_mixin
• prefer_null_aware_operators
• prefer_relative_imports
• prefer_single_quotes
• prefer_spread_collections
• prefer_typing_uninitialized_variables
• prefer_void_to_null
• provide_deprecation_message
• pub/package_names
• pub/sort_pub_dependencies
• public_member_api_docs
• recursive_getters
• slash_for_doc_comments
• sort_child_properties_last
• sort_constructors_first
• sort_unnamed_constructors_first
• super_goes_last
• test_types_in_equals
• throw_in_finally
• type_annotate_public_apis
• type_init_formals
• unawaited_futures
• unnecessary_await_in_return
• unnecessary_brace_in_string_interps
• unnecessary_const
• unnecessary_final
• unnecessary_getters
• unnecessary_getters_setters
• unnecessary_lambdas
• 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
• use_full_hex_values_for_flutter_colors
• use_function_type_syntax_for_parameters
• use_rethrow_when_possible
• use_setters_to_change_properties
• use_string_buffers
• use_to_and_as_if_applicable
• valid_regexps
• void_checks

[bwilkerson]

@pq We should decide how we want to handle the rules that will be obsolete under NNBD. We could

• do nothing,
• add a warning to the analysis options file (though the rules might still be useful if there are opted-out libraries in the package), or
• mark them as deprecated (though that impacts code that has not yet migrated).

@davidmorgan Some of the obsolete rules are in the pedantic rule set, so this decision will impact you as well.

[davidmorgan]

Thanks.

It looks like https://dart-lang.github.io/linter/lints/super_goes_last.html might be prior art :)

[bwilkerson]

Yes. At one point the super initialize was allowed to appear anywhere in the initializer list, so we added a lint to enforce best practice. But now it's mandated by the spec, so the lint is deprecated.

[pq]

I guess another option is to:

• add an optional SDK (version or feature) constraint to lints and only have them fire when conditions are met

(This could be combined w/ options 2 and 3 above.)

[bwilkerson]

We might very well want to do that in order to better support libraries that have opted to use an earlier version of the SDK.