在《如何做好 Code Review》中我論述過程式碼審查對於保證程式碼品質的重要性,最近開始採用Git Hooks的方式為Flutter專案增加提交前的強制自我審查。這樣做的好處在於將機械化檢查交給電腦,把思考的部分留給大腦。
我認為程式碼提交前需要做的最基本檢查包括格式和程式碼規範。前者交給Prettier,後者由Analyze負責。
Lefthook
我採用Lefthook實現Git鉤子,如果你有更好的選擇,歡迎推薦分享。
# Mac
brew install lefthook && lefthook install
安裝Lefthook後,在專案根目錄下執行lefthook install
命令來生成lefthook.yml
檔案,並在其中的pre-commit > commands
節點下新增兩項配置:
prettier:
glob: "*.dart"
run: flutter format {staged_files} && git add {staged_files}
linter:
run: flutter analyze
Analyze
flutter analyze
通過flutter_lints外掛對Dart程式碼進行靜態語言檢查,檢查規則配置在analysis_options.yaml
檔案中。但是開啟該檔案可以看到,Flutter 並沒有為我們配置任何預設規則。我把我正在採用的規則配置放在文末,歡迎酌情采納。
接下來我們可以測試一下配置能否正常工作。比如,將main()
替換為:
void main() {
const title= 'Flutter';
runApp(const MyApp());}
aa() {}
然後執行命令:
git add .&&git commit -m 'Commit for analysis.'
接下來你會發現,Prettier 將程式碼格式化為:
void main() {
const title = 'Flutter';
runApp(const MyApp());
}
aa() {}
但是靜態檢查沒有通過,因為title
變數沒有被使用、函式aa
沒有返回型別等:
EXECUTE > linter
Analyzing demo_lint_flutter...
info • The value of the local variable 'title' isn't used • lib/main.dart:4:9 • unused_local_variable
info • The function 'aa' should have a return type but doesn't • lib/main.dart:8:1 • always_declare_return_types
info • Type annotate public APIs • lib/main.dart:8:1 • type_annotate_public_apis
3 issues found. (ran in 2.0s)
強烈建議你在接下來的每一個Flutter專案裡都堅持這樣做,不要提交Smelling Code。
analysis_options.yaml
include: package:flutter_lints/flutter.yaml
analyzer:
strong-mode:
implicit-casts: false
errors:
missing_required_param: warning
missing_return: warning
todo: ignore
linter:
rules:
always_declare_return_types: true
always_require_non_null_named_parameters: true
annotate_overrides: true
avoid_bool_literals_in_conditional_expressions: true
avoid_catching_errors: true
avoid_classes_with_only_static_members: true
avoid_empty_else: true
avoid_escaping_inner_quotes: true
avoid_field_initializers_in_const_classes: true
avoid_function_literals_in_foreach_calls: true
avoid_implementing_value_types: true
avoid_init_to_null: true
avoid_multiple_declarations_per_line: true
avoid_null_checks_in_equality_operators: true
avoid_positional_boolean_parameters: true
avoid_print: true
avoid_private_typedef_functions: true
avoid_redundant_argument_values: true
avoid_relative_lib_imports: true
avoid_return_types_on_setters: true
avoid_returning_null_for_future: true
avoid_returning_null_for_void: true
avoid_setters_without_getters: true
avoid_shadowing_type_parameters: true
avoid_single_cascade_in_expression_statements: true
avoid_type_to_string: true
avoid_types_as_parameter_names: true
avoid_unnecessary_containers: true
avoid_unused_constructor_parameters: true
avoid_void_async: true
avoid_web_libraries_in_flutter: true
await_only_futures: true
camel_case_extensions: true
camel_case_types: true
cancel_subscriptions: true
cast_nullable_to_non_nullable: true
constant_identifier_names: true
control_flow_in_finally: true
curly_braces_in_flow_control_structures: true
depend_on_referenced_packages: true
deprecated_consistency: true
empty_catches: true
empty_constructor_bodies: true
empty_statements: true
eol_at_end_of_file: true
exhaustive_cases: true
file_names: true
hash_and_equals: true
implementation_imports: true
invariant_booleans: true
iterable_contains_unrelated_type: true
join_return_with_assignment: true
leading_newlines_in_multiline_strings: true
library_names: true
library_prefixes: true
list_remove_unrelated_type: true
missing_whitespace_between_adjacent_strings: true
no_adjacent_strings_in_list: true
no_duplicate_case_values: true
no_logic_in_create_state: true
no_runtimeType_toString: true
non_constant_identifier_names: true
noop_primitive_operations: true
null_check_on_nullable_type_parameter: true
null_closures: true
overridden_fields: true
package_names: true
package_prefixed_library_names: true
parameter_assignments: true
prefer_asserts_in_initializer_lists: true
prefer_collection_literals: true
prefer_conditional_assignment: true
prefer_const_constructors: true
prefer_const_constructors_in_immutables: true
prefer_const_declarations: true
prefer_const_literals_to_create_immutables: true
prefer_constructors_over_static_methods: true
prefer_contains: true
prefer_equal_for_default_values: true
prefer_final_fields: true
prefer_final_in_for_each: true
prefer_final_locals: true
prefer_for_elements_to_map_fromIterable: true
prefer_function_declarations_over_variables: true
prefer_generic_function_type_aliases: true
prefer_if_elements_to_conditional_expressions: true
prefer_if_null_operators: true
prefer_initializing_formals: true
prefer_inlined_adds: true
prefer_interpolation_to_compose_strings: true
prefer_is_empty: true
prefer_is_not_empty: true
prefer_is_not_operator: true
prefer_iterable_whereType: true
prefer_null_aware_method_calls: true
prefer_spread_collections: true
prefer_typing_uninitialized_variables: true
prefer_void_to_null: true
provide_deprecation_message: true
recursive_getters: true
require_trailing_commas: true
sized_box_for_whitespace: true
slash_for_doc_comments: true
sort_child_properties_last: true
sort_unnamed_constructors_first: true
test_types_in_equals: true
throw_in_finally: true
tighten_type_of_initializing_formals: true
type_annotate_public_apis: true
type_init_formals: true
unnecessary_await_in_return: true
unnecessary_brace_in_string_interps: true
unnecessary_const: true
unnecessary_getters_setters: true
unnecessary_new: true
unnecessary_null_aware_assignments: true
unnecessary_null_checks: true
unnecessary_null_in_if_null_operators: true
unnecessary_nullable_for_final_variable_declarations: true
unnecessary_overrides: true
unnecessary_parenthesis: true
unnecessary_raw_strings: true
unnecessary_statements: true
unnecessary_string_escapes: true
unnecessary_string_interpolations: true
unnecessary_this: true
unrelated_type_equality_checks: true
unsafe_html: true
use_build_context_synchronously: true
use_full_hex_values_for_flutter_colors: true
use_function_type_syntax_for_parameters: true
use_named_constants: true
use_late_for_private_fields_and_variables: true
use_rethrow_when_possible: true
use_setters_to_change_properties: true
use_string_buffers: true
use_test_throws_matchers: true
valid_regexps: true
void_checks: true