Linter: support for a package cache (to avoid needless pubspec parses)
Currently in avoid_web_libraries_in_flutter we need to parse pubspecs to identify Flutter web plugins:
This happens _per_ compilation unit. It would be great if we could cache this information sensibly.
/cc @scheglov @bwilkerson @srawlins for thoughts.
pq
All 10 comments
Parsing a pubspec only works in a pub package. I assume we have (or will have) a different way of identifying flutter web plugins internally. It kind of seems like a package-specific test, so perhaps it should be added to WorkspacePackage (which really needs to be renamed to just Package, and the sooner the better).
bwilkerson
on 1 Nov 2019
That's my assumption too. Not sure what the plan is there.
a different way of identifying flutter web plugins internally.
Maybe @yjbanov or @hterkelsen know?
pq
on 1 Nov 2019
Some other art/hackery in this area: Dartdoc has a package information cache where, given a library element, we look up its package information. It has good properties for dartdoc at least and is extensible to other kinds of packages besides SDK and pub. https://github.com/dart-lang/dartdoc/blob/master/lib/src/package_meta.dart#L96
jcollins-g
on 1 Nov 2019
Do we know the performance impact of avoid_web_libraries_in_flutter? If we do not know, or if we know that it's negative, let's revert until this issue is resolved.
/cc @chingjun on how things work internally, but you probably want to take the discussion offline.
yjbanov
on 1 Nov 2019
Doing some quick benchmarking, the numbers don't look terrible.
Running against flutter_gallery I'm seeing about 9ms spent in this lint (of 1107 total).
dart bin/linter.dart --benchmark -q -c ../flutter/packages/flutter/lib/analysis_options_user.yaml ../flutter/examples/flutter_gallery
------------------------------------------------------
Timings ms
------------------------------------------------------
prefer_relative_imports 232
flutter_style_todos 84
lines_longer_than_80_chars 79
prefer_double_quotes 63
invariant_booleans 61
unnecessary_this 34
cancel_subscriptions 27
prefer_const_constructors 27
prefer_const_declarations 23
avoid_returning_this 19
always_require_non_null_named_parameters 17
prefer_is_not_empty 17
public_member_api_docs 17
prefer_contains 16
null_closures 15
prefer_is_empty 15
close_sinks 14
directives_ordering 13
void_checks 13
avoid_positional_boolean_parameters 13
prefer_void_to_null 12
avoid_returning_null 10
prefer_final_fields 10
avoid_web_libraries_in_flutter 9
<snip ... />
Full run.
dart bin/linter.dart --benchmark -q -c ../flutter/packages/flutter/lib/analysis_options_user.yaml ../flutter/examples/flutter_gallery
------------------------------------------------------
Timings ms
------------------------------------------------------
prefer_relative_imports 232
flutter_style_todos 84
lines_longer_than_80_chars 79
prefer_double_quotes 63
invariant_booleans 61
unnecessary_this 34
cancel_subscriptions 27
prefer_const_constructors 27
prefer_const_declarations 23
avoid_returning_this 19
always_require_non_null_named_parameters 17
prefer_is_not_empty 17
public_member_api_docs 17
prefer_contains 16
null_closures 15
prefer_is_empty 15
close_sinks 14
directives_ordering 13
void_checks 13
avoid_positional_boolean_parameters 13
prefer_void_to_null 12
avoid_returning_null 10
prefer_final_fields 10
avoid_web_libraries_in_flutter 9
non_constant_identifier_names 9
package_api_docs 9
unnecessary_overrides 9
control_flow_in_finally 8
cascade_invocations 8
always_specify_types 7
avoid_unnecessary_containers 7
unnecessary_lambdas 6
avoid_print 6
annotate_overrides 6
iterable_contains_unrelated_type 5
omit_local_variable_types 5
always_put_control_body_on_new_line 5
file_names 5
avoid_renaming_method_parameters 5
overridden_fields 5
parameter_assignments 5
prefer_initializing_formals 5
avoid_slow_async_io 5
prefer_collection_literals 5
avoid_types_on_closure_parameters 5
recursive_getters 5
prefer_int_literals 4
unnecessary_const 4
join_return_with_assignment 4
avoid_void_async 4
sort_constructors_first 4
avoid_unused_constructor_parameters 4
use_setters_to_change_properties 4
constant_identifier_names 4
sort_child_properties_last 3
use_to_and_as_if_applicable 3
avoid_function_literals_in_foreach_calls 3
prefer_const_literals_to_create_immutables 3
always_put_required_named_parameters_first 3
avoid_types_as_parameter_names 3
prefer_single_quotes 3
prefer_expression_function_bodies 3
diagnostic_describe_all_properties 3
unrelated_type_equality_checks 2
avoid_returning_null_for_future 2
prefer_spread_collections 2
prefer_for_elements_to_map_fromIterable 2
prefer_final_locals 2
avoid_setters_without_getters 2
no_duplicate_case_values 2
unawaited_futures 2
unnecessary_statements 2
avoid_equals_and_hash_code_on_mutable_classes 2
prefer_iterable_whereType 2
hash_and_equals 2
implementation_imports 2
prefer_inlined_adds 2
curly_braces_in_flow_control_structures 2
prefer_if_null_operators 2
type_annotate_public_apis 2
list_remove_unrelated_type 2
unnecessary_getters_setters 2
slash_for_doc_comments 2
prefer_const_constructors_in_immutables 2
avoid_null_checks_in_equality_operators 2
camel_case_types 2
avoid_init_to_null 2
unnecessary_parenthesis 1
only_throw_errors 1
unsafe_html 1
prefer_asserts_in_initializer_lists 1
avoid_field_initializers_in_const_classes 1
valid_regexps 1
avoid_shadowing_type_parameters 1
unnecessary_await_in_return 1
avoid_returning_null_for_void 1
unnecessary_new 1
always_declare_return_types 1
avoid_annotating_with_dynamic 1
prefer_foreach 1
provide_deprecation_message 1
prefer_constructors_over_static_methods 1
avoid_relative_lib_imports 1
avoid_classes_with_only_static_members 1
sort_unnamed_constructors_first 1
use_full_hex_values_for_flutter_colors 1
unnecessary_brace_in_string_interps 1
use_string_buffers 1
literal_only_boolean_expressions 1
prefer_function_declarations_over_variables 1
prefer_interpolation_to_compose_strings 1
library_prefixes 1
use_function_type_syntax_for_parameters 0
avoid_catches_without_on_clauses 0
test_types_in_equals 0
library_names 0
empty_constructor_bodies 0
prefer_null_aware_operators 0
empty_catches 0
avoid_js_rounded_ints 0
package_prefixed_library_names 0
prefer_typing_uninitialized_variables 0
throw_in_finally 0
avoid_implementing_value_types 0
prefer_final_in_for_each 0
comment_references 0
no_adjacent_strings_in_list 0
avoid_double_and_int_checks 0
await_only_futures 0
prefer_bool_in_asserts 0
avoid_private_typedef_functions 0
avoid_catching_errors 0
unnecessary_null_aware_assignments 0
avoid_empty_else 0
prefer_generic_function_type_aliases 0
avoid_return_types_on_setters 0
unnecessary_null_in_if_null_operators 0
prefer_asserts_with_message 0
use_rethrow_when_possible 0
prefer_equal_for_default_values 0
avoid_as 0
avoid_single_cascade_in_expression_statements 0
one_member_abstracts 0
prefer_adjacent_string_concatenation 0
prefer_conditional_assignment 0
camel_case_extensions 0
avoid_bool_literals_in_conditional_expressions 0
empty_statements 0
super_goes_last 0
prefer_mixin 0
prefer_if_elements_to_conditional_expressions 0
prefer_is_not_operator 0
type_init_formals 0
------------------------------------------------------
Total 1107
------------------------------------------------------
/fyi @devoncarew
pq
on 1 Nov 2019
(Note that prefer_relative_imports is getting a tune-up in #1812.)
pq
on 1 Nov 2019
(Note that
prefer_relative_importsis getting a tune-up in #1812.)
Thanks for that! I didn't realize so much time was going towards it. Mea culpa!
devoncarew
on 1 Nov 2019
Mea culpa!
No worries! I was surprised too. The extra good news is that as a result we have a way better approach for these kinds of checks moving forward (and one that should play nice in google3).
pq
on 1 Nov 2019
In google3 we depend on other mechanism and not on the linter to avoid web libraries in flutter.
chingjun
on 1 Nov 2019
Fantastic @chingjun. This is great to know!
pq
on 1 Nov 2019
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