Flutter的强制自我审查

在《如何做好 Code Review》中我论述过代码审查对于保证代码品质的重要性，最近开始采用Git Hooks的方式为Flutter项目增加提交前的强制自我审查。这样做的好处在于将机械化检查交给电脑，把思考的部分留给大脑。

我认为代码提交前需要做的最基本检查包括格式和代码规范。前者交给Prettier，后者由Analyze负责。

Lefthook

我采用Lefthook实现Git钩子，如果你有更好的选择，欢迎推荐分享。

# Macbrew install lefthook && lefthook install

安装Lefthook后，在项目根目录下运行lefthook install命令来生成lefthook.yml文件，并在其中的pre-commit > commands节点下添加两项配置：

prettier:  glob: "*.dart"  run: flutter format {staged_files} && git add {staged_files}linter:  run: flutter analyze

Analyze

flutter analyze通过flutter_lints插件对Dart代码进行静态语言检查，检查规则配置在analysis_options.yaml文件中。但是打开该文件可以看到，Flutter 并没有为我们配置任何默认规则。我把我正在采用的规则配置放在文末，欢迎酌情采纳。

接下来我们可以测试一下配置能否正常工作。比如，将main()替换为：

void main() {  const title=    'Flutter';  runApp(const MyApp());}aa()         {}

然后运行命令：

git add .&&git commit -m 'Commit for analysis.'

接下来你会发现，Prettier 将代码格式化为：

void main() {  const title = 'Flutter';  runApp(const MyApp());}aa() {}

但是静态检查没有通过，因为title变量没有被使用、函数aa没有返回类型等：

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_apis3 issues found. (ran in 2.0s)

强烈建议你在接下来的每一个Flutter项目里都坚持这样做，不要提交Smelling Code。

analysis_options.yaml

include: package:flutter_lints/flutter.yamlanalyzer:  strong-mode:    implicit-casts: false  errors:    missing_required_param: warning    missing_return: warning    todo: ignorelinter:  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