[enhanced-parts] Linter Support

[pq]

A meta-issue to discuss and track work on linter support for enhanced-parts.

• enhanced-parts feature spec
• Experiment flag: Feature.enhanced_parts

Existing Lints

Some existing lints will need tests (minimally) and possibly enhanced implementations.

• [enhanced-parts] evaluate support for always_declare_return_types
• [enhanced-parts] evaluate support for always_put_control_body_on_new_line
• [enhanced-parts] evaluate support for always_put_required_named_parameters_first
• [enhanced-parts] evaluate support for always_specify_types
• [enhanced-parts] tests for always_use_package_imports #5085
• [enhanced-parts] evaluate support for annotate_overrides
• [enhanced-parts] evaluate support for annotate_redeclares [experimental]
• [enhanced-parts] evaluate support for avoid_annotating_with_dynamic
• [enhanced-parts] evaluate support for avoid_bool_literals_in_conditional_expressions
• [enhanced-parts] evaluate support for avoid_catches_without_on_clauses
• [enhanced-parts] evaluate support for avoid_catching_errors
• [enhanced-parts] evaluate support for avoid_classes_with_only_static_members
• [enhanced-parts] evaluate support for avoid_double_and_int_checks
• [enhanced-parts] evaluate support for avoid_dynamic_calls
• [enhanced-parts] evaluate support for avoid_empty_else
• [enhanced-parts] evaluate support for avoid_equals_and_hash_code_on_mutable_classes
• [enhanced-parts] evaluate support for avoid_escaping_inner_quotes
• [enhanced-parts] evaluate support for avoid_field_initializers_in_const_classes
• [enhanced-parts] evaluate support for avoid_final_parameters
• [enhanced-parts] evaluate support for avoid_function_literals_in_foreach_calls
• [enhanced-parts] evaluate support for avoid_implementing_value_types
• [enhanced-parts] evaluate support for avoid_init_to_null
• [enhanced-parts] evaluate support for avoid_js_rounded_ints
• [enhanced-parts] evaluate support for avoid_multiple_declarations_per_line
• [enhanced-parts] evaluate support for avoid_null_checks_in_equality_operators
• [enhanced-parts] evaluate support for avoid_positional_boolean_parameters
• [enhanced-parts] evaluate support for avoid_print
• [enhanced-parts] evaluate support for avoid_private_typedef_functions
• [enhanced-parts] evaluate support for avoid_redundant_argument_values
• [enhanced-parts] tests for avoid_relative_lib_imports #5080
• [enhanced-parts] evaluate support for avoid_renaming_method_parameters
• [enhanced-parts] evaluate support for avoid_return_types_on_setters
• [enhanced-parts] evaluate support for avoid_returning_null_for_void
• [enhanced-parts] evaluate support for avoid_returning_this
• [enhanced-parts] evaluate support for avoid_setters_without_getters
• [enhanced-parts] evaluate support for avoid_shadowing_type_parameters
• [enhanced-parts] evaluate support for avoid_single_cascade_in_expression_statements
• [enhanced-parts] evaluate support for avoid_slow_async_io
• [enhanced-parts] evaluate support for avoid_type_to_string
• [enhanced-parts] evaluate support for avoid_types_as_parameter_names
• [enhanced-parts] evaluate support for avoid_types_on_closure_parameters
• [enhanced-parts] evaluate support for avoid_unnecessary_containers
• [enhanced-parts] evaluate support for avoid_unused_constructor_parameters
• [enhanced-parts] evaluate support for avoid_void_async
• [enhanced-parts] evaluate support for avoid_web_libraries_in_flutter
• [enhanced-parts] evaluate support for await_only_futures
• [enhanced-parts] evaluate support for camel_case_extensions
• [enhanced-parts] evaluate support for camel_case_types
• [enhanced-parts] evaluate support for cancel_subscriptions
• [enhanced-parts] evaluate support for cascade_invocations
• [enhanced-parts] evaluate support for cast_nullable_to_non_nullable
• [enhanced-parts] evaluate support for close_sinks
• [enhanced-parts] evaluate support for collection_methods_unrelated_type
• [enhanced-parts] evaluate support for combinators_ordering
• [enhanced-parts] evaluate support for comment_references
• [enhanced-parts] tests for conditional_uri_does_not_exist #5081
• [enhanced-parts] evaluate support for constant_identifier_names
• [enhanced-parts] evaluate support for control_flow_in_finally
• [enhanced-parts] evaluate support for curly_braces_in_flow_control_structures
• [enhanced-parts] evaluate support for dangling_library_doc_comments
• [enhanced-parts] evaluate support for depend_on_referenced_packages
• [enhanced-parts] evaluate support for deprecated_consistency
• [enhanced-parts] evaluate support for deprecated_member_use_from_same_package
• [enhanced-parts] evaluate support for diagnostic_describe_all_properties
• [enhanced-parts] evaluate support for directives_ordering
• [enhanced-parts] evaluate support for discarded_futures
• [enhanced-parts] evaluate support for document_ignores
• [enhanced-parts] evaluate support for do_not_use_environment
• [enhanced-parts] evaluate support for empty_catches
• [enhanced-parts] evaluate support for empty_constructor_bodies
• [enhanced-parts] evaluate support for empty_statements
• [enhanced-parts] evaluate support for eol_at_end_of_file
• [enhanced-parts] evaluate support for erase_dart_type_extension_types
• [enhanced-parts] evaluate support for exhaustive_cases
• [enhanced-parts] evaluate support for file_names
• [enhanced-parts] evaluate support for flutter_style_todos
• [enhanced-parts] evaluate support for hash_and_equals
• [enhanced-parts] tests for implementation_imports #5082
• [enhanced-parts] evaluate support for implicit_call_tearoffs
• [enhanced-parts] evaluate support for implicit_reopen [experimental]
• [enhanced-parts] evaluate support for invalid_case_patterns [experimental]
• [enhanced-parts] evaluate support for join_return_with_assignment
• [enhanced-parts] evaluate support for invalid_runtime_check_with_js_interop_types
• [enhanced-parts] evaluate support for leading_newlines_in_multiline_strings
• [enhanced-parts] tests for library_annotations (fix for "part of") #5084
• [enhanced-parts] evaluate support for library_names
• [enhanced-parts] evaluate support for library_prefixes
• [enhanced-parts] evaluate support for library_private_types_in_public_api
• [enhanced-parts] evaluate support for lines_longer_than_80_chars
• [enhanced-parts] evaluate support for literal_only_boolean_expressions
• [enhanced-parts] evaluate support for matching_super_parameters
• [enhanced-parts] evaluate support for missing_code_block_language_in_doc_comment
• [enhanced-parts] evaluate support for missing_whitespace_between_adjacent_strings
• [enhanced-parts] evaluate support for no_adjacent_strings_in_list
• [enhanced-parts] evaluate support for no_default_cases [experimental]
• [enhanced-parts] evaluate support for no_duplicate_case_values
• [enhanced-parts] evaluate support for no_leading_underscores_for_library_prefixes
• [enhanced-parts] evaluate support for no_leading_underscores_for_local_identifiers
• [enhanced-parts] evaluate support for no_literal_bool_comparisons
• [enhanced-parts] evaluate support for no_logic_in_create_state
• [enhanced-parts] evaluate support for no_runtimeType_toString
• [enhanced-parts] evaluate support for no_self_assignments
• [enhanced-parts] evaluate support for no_wildcard_variable_uses
• [enhanced-parts] evaluate support for non_constant_identifier_names
• [enhanced-parts] evaluate support for noop_primitive_operations
• [enhanced-parts] evaluate support for null_check_on_nullable_type_parameter
• [enhanced-parts] evaluate support for null_closures
• [enhanced-parts] evaluate support for omit_local_variable_types
• [enhanced-parts] evaluate support for omit_obvious_local_variable_types [experimental]
• [enhanced-parts] evaluate support for one_member_abstracts
• [enhanced-parts] evaluate support for only_throw_errors
• [enhanced-parts] evaluate support for overridden_fields
• [enhanced-parts] evaluate support for package_api_docs
• [enhanced-parts] evaluate support for package_names
• [enhanced-parts] evaluate support for package_prefixed_library_names
• [enhanced-parts] evaluate support for parameter_assignments
• [enhanced-parts] evaluate support for prefer_adjacent_string_concatenation
• [enhanced-parts] evaluate support for prefer_asserts_in_initializer_lists
• [enhanced-parts] evaluate support for prefer_asserts_with_message
• [enhanced-parts] evaluate support for prefer_collection_literals
• [enhanced-parts] evaluate support for prefer_conditional_assignment
• [enhanced-parts] evaluate support for prefer_const_constructors
• [enhanced-parts] evaluate support for prefer_const_constructors_in_immutables
• [enhanced-parts] evaluate support for prefer_const_declarations
• [enhanced-parts] evaluate support for prefer_const_literals_to_create_immutables
• [enhanced-parts] evaluate support for prefer_constructors_over_static_methods
• [enhanced-parts] evaluate support for prefer_contains
• [enhanced-parts] evaluate support for prefer_double_quotes
• [enhanced-parts] evaluate support for prefer_expression_function_bodies
• [enhanced-parts] evaluate support for prefer_final_fields
• [enhanced-parts] evaluate support for prefer_final_in_for_each
• [enhanced-parts] evaluate support for prefer_final_locals
• [enhanced-parts] evaluate support for prefer_final_parameters
• [enhanced-parts] evaluate support for prefer_for_elements_to_map_fromIterable
• [enhanced-parts] evaluate support for prefer_foreach
• [enhanced-parts] evaluate support for prefer_function_declarations_over_variables
• [enhanced-parts] evaluate support for prefer_generic_function_type_aliases
• [enhanced-parts] evaluate support for prefer_if_elements_to_conditional_expressions
• [enhanced-parts] evaluate support for prefer_if_null_operators
• [enhanced-parts] evaluate support for prefer_initializing_formals
• [enhanced-parts] evaluate support for prefer_inlined_adds
• [enhanced-parts] evaluate support for prefer_int_literals
• [enhanced-parts] evaluate support for prefer_interpolation_to_compose_strings
• [enhanced-parts] evaluate support for prefer_is_empty
• [enhanced-parts] evaluate support for prefer_is_not_empty
• [enhanced-parts] evaluate support for prefer_is_not_operator
• [enhanced-parts] evaluate support for prefer_iterable_whereType
• [enhanced-parts] evaluate support for prefer_mixin
• [enhanced-parts] evaluate support for prefer_null_aware_method_calls
• [enhanced-parts] evaluate support for prefer_null_aware_operators
• [enhanced-parts] tests for prefer_relative_imports #5083
• [enhanced-parts] evaluate support for prefer_single_quotes
• [enhanced-parts] evaluate support for prefer_spread_collections
• [enhanced-parts] evaluate support for prefer_typing_uninitialized_variables
• [enhanced-parts] evaluate support for prefer_void_to_null
• [enhanced-parts] evaluate support for provide_deprecation_message
• [enhanced-parts] tests for public_member_api_docs #5090
• [enhanced-parts] evaluate support for recursive_getters
• [enhanced-parts] evaluate support for require_trailing_commas
• [enhanced-parts] evaluate support for secure_pubspec_urls
• [enhanced-parts] evaluate support for sized_box_for_whitespace
• [enhanced-parts] evaluate support for sized_box_shrink_expand
• [enhanced-parts] evaluate support for slash_for_doc_comments
• [enhanced-parts] evaluate support for sort_child_properties_last
• [enhanced-parts] evaluate support for sort_constructors_first
• [enhanced-parts] evaluate support for sort_pub_dependencies
• [enhanced-parts] evaluate support for sort_unnamed_constructors_first
• [enhanced-parts] evaluate support for test_types_in_equals
• [enhanced-parts] evaluate support for throw_in_finally
• [enhanced-parts] evaluate support for tighten_type_of_initializing_formals
• [enhanced-parts] evaluate support for type_annotate_public_apis
• [enhanced-parts] evaluate support for type_init_formals
• [enhanced-parts] evaluate support for type_literal_in_constant_pattern
• [enhanced-parts] evaluate support for unawaited_futures
• [enhanced-parts] evaluate support for unintended_html_in_doc_comment
• [enhanced-parts] evaluate support for unnecessary_await_in_return
• [enhanced-parts] evaluate support for unnecessary_brace_in_string_interps
• [enhanced-parts] evaluate support for unnecessary_breaks
• [enhanced-parts] evaluate support for unnecessary_const
• [enhanced-parts] evaluate support for unnecessary_constructor_name
• [enhanced-parts] evaluate support for unnecessary_final
• [enhanced-parts] evaluate support for unnecessary_getters_setters
• [enhanced-parts] evaluate support for unnecessary_lambdas
• [enhanced-parts] evaluate support for unnecessary_late
• [enhanced-parts] evaluate support for unnecessary_library_directive
• [enhanced-parts] evaluate support for unnecessary_library_name
• [enhanced-parts] evaluate support for unnecessary_new
• [enhanced-parts] evaluate support for unnecessary_null_aware_assignments
• [enhanced-parts] evaluate support for unnecessary_null_aware_operator_on_extension_on_nullable
• [enhanced-parts] evaluate support for unnecessary_null_checks [experimental]
• [enhanced-parts] evaluate support for unnecessary_null_in_if_null_operators
• [enhanced-parts] evaluate support for unnecessary_nullable_for_final_variable_declarations
• [enhanced-parts] evaluate support for unnecessary_overrides
• [enhanced-parts] evaluate support for unnecessary_parenthesis
• [enhanced-parts] evaluate support for unnecessary_raw_strings
• [enhanced-parts] evaluate support for unnecessary_statements
• [enhanced-parts] evaluate support for unnecessary_string_escapes
• [enhanced-parts] evaluate support for unnecessary_string_interpolations
• [enhanced-parts] evaluate support for unnecessary_this
• [enhanced-parts] evaluate support for unnecessary_to_list_in_spreads
• [enhanced-parts] evaluate support for unreachable_from_main
• [enhanced-parts] evaluate support for unrelated_type_equality_checks
• [enhanced-parts] evaluate support for unsafe_html
• [enhanced-parts] evaluate support for use_build_context_synchronously
• [enhanced-parts] evaluate support for use_colored_box
• [enhanced-parts] evaluate support for use_decorated_box
• [enhanced-parts] evaluate support for use_enums
• [enhanced-parts] evaluate support for use_full_hex_values_for_flutter_colors
• [enhanced-parts] evaluate support for use_function_type_syntax_for_parameters
• [enhanced-parts] evaluate support for use_if_null_to_convert_nulls_to_bools
• [enhanced-parts] evaluate support for use_is_even_rather_than_modulo
• [enhanced-parts] evaluate support for use_key_in_widget_constructors
• [enhanced-parts] evaluate support for use_late_for_private_fields_and_variables [experimental]
• [enhanced-parts] evaluate support for use_named_constants
• [enhanced-parts] evaluate support for use_raw_strings
• [enhanced-parts] evaluate support for use_rethrow_when_possible
• [enhanced-parts] evaluate support for use_setters_to_change_properties
• [enhanced-parts] evaluate support for use_string_buffers
• [enhanced-parts] support for use_string_in_part_of_directives #5026
• [enhanced-parts] evaluate support for use_super_parameters [experimental]
• [enhanced-parts] evaluate support for use_test_throws_matchers
• [enhanced-parts] evaluate support for use_to_and_as_if_applicable
• [enhanced-parts] evaluate support for valid_regexps
• [enhanced-parts] evaluate support for void_checks

General Part Support

There are a number of outstanding issues with our support for parts. In support of this feature (and in anticipation) of greater adoption of parts, we might consider prioritizing some fixes.

• Apply directives_ordering to part #4945
• Analyzer: prefer_final_fields confused when used 'part' #4992
• prefer_final_fields false positive if field is set from another parts #2697

[bwilkerson]

See also dart-lang/sdk#56213, and note that the experiment name used here is different from the name used in the SDK issues.

[pq]

I'm making my way through the lints and thinking in general that they should "just work". If any exceptions jump out at anyone, I'd be grateful for the input!

/cc @eernstg @bwilkerson @lrhn

[srawlins]

• avoid_relative_lib_imports is checked as complete, but I don't see new tests for imports in parts.
• conditional_uri_does_not_exist: same.
• implementation_imports: same.
• library_annotations: the impl needs changing I think, so that it returns early if it finds a PartOfDirective, so that it doesn't suggest adding a library directive in a part file.
• prefer_relative_imports: same.

[eernstg]

A couple of other things came to mind:

• dangling_library_doc_comments, would presumably lint a DartDoc comment on a <partHeader> (part of ...), but it seems plausible that this DartDoc comment could play a role for the part which is similar to the role played by a DartDoc comment on a <libraryName> for the library as a whole. Perhaps it needs an update or a test?
• Is it being tested that locations that are supposed to trigger a lint (any lint, not one which is part specific) will also do so when the location is in a nested part file?

[lrhn]

For dangling_library_doc_comments, it only seem to apply to the library file, so no change should be necessary.
I don't expect doc-comments on part of directives to behave differently from today. I don't know what they do today, but I'd expect them to be either ignored or concatenated with the library documentation from the library file. (Testing: Seems to be ignored.)

All the ones that refer to URIs or imports should definitely not bail out early on seeing part of. Then they should behave the same for the imports and URIs they find.

library_annotations shouldn't need changing. It can find a part of directive today, so nothing changed there. Any issues are pre-existing.