How to use Editorconfig?

2023-06-30
Having tidy code with shared formatting rules is useful and more elegant.
In a .NET application, you can add an editorconfig file with all the formatting rules.
Scope of the file

The file must be named .editorconfig, with the starting dot.
If you put it in the root of the project, it will be applied to all the files.
You can have more than one file in your repository: in fact, you can narrow down the scope of an editorconfig files by adding a new file in a specific folder or project.
Formatting the code using CMD

You can format all the files by running dotnet format.
You can also specify which kind of formatting you want to apply:
dotnet format whitespace runs whitespace formatting;
dotnet format style runs code style analyzers;
dotnet format analyzers runs 3rd party analyzers.
At the end of the article ,you can find the one I’m using (it can be changed if I find more useful rules).
How to edit that file

You can edit it manually, but updating the content of the .editorconfig file.
If you prefer a UI, you can locate that file in the Solution Explorer in Visual Studio, open it, and edit it using a UI editor:
Visual Studio editor
My personal EditorConfig

# Version: 4.1.1 (Using https://semver.org/)
# Updated: 2022-05-23
# See https://github.com/RehanSaeed/EditorConfig/releases for release notes.
# See https://github.com/RehanSaeed/EditorConfig for updates to this file.
# See http://EditorConfig.org for more information about .editorconfig files.

##########################################
# Common Settings
##########################################

# This file is the top-most EditorConfig file
root = true

# All Files
[*]
charset = utf-8
indent_style = space
indent_size = 4
insert_final_newline = true
trim_trailing_whitespace = true

##########################################
# File Extension Settings
##########################################

# Visual Studio Solution Files
[*.sln]
indent_style = tab

# Visual Studio XML Project Files
[*.{csproj,vbproj,vcxproj.filters,proj,projitems,shproj}]
indent_size = 2

# XML Configuration Files
[*.{xml,config,props,targets,nuspec,resx,ruleset,vsixmanifest,vsct}]
indent_size = 2

# JSON Files
[*.{json,json5,webmanifest}]
indent_size = 2

# YAML Files
[*.{yml,yaml}]
indent_size = 2

# Markdown Files
[*.{md,mdx}]
trim_trailing_whitespace = false

# Web Files
[*.{htm,html,js,jsm,ts,tsx,cjs,cts,ctsx,mjs,mts,mtsx,css,sass,scss,less,pcss,svg,vue}]
indent_size = 2

# Batch Files
[*.{cmd,bat}]
end_of_line = crlf

# Bash Files
[*.sh]
end_of_line = lf

# Makefiles
[Makefile]
indent_style = tab

##########################################
# Default .NET Code Style Severities
# https://docs.microsoft.com/dotnet/fundamentals/code-analysis/configuration-options#scope
##########################################

[*.{cs,csx,cake,vb,vbx}]
# Default Severity for all .NET Code Style rules below
dotnet_analyzer_diagnostic.severity = warning

##########################################
# Language Rules
# https://docs.microsoft.com/dotnet/fundamentals/code-analysis/style-rules/language-rules
##########################################

# .NET Style Rules
# https://docs.microsoft.com/dotnet/fundamentals/code-analysis/style-rules/language-rules#net-style-rules
[*.{cs,csx,cake,vb,vbx}]
# "this." and "Me." qualifiers
dotnet_style_qualification_for_field = false:warning
dotnet_style_qualification_for_property = false:warning
dotnet_style_qualification_for_method = false:warning
dotnet_style_qualification_for_event = false:warning
# Language keywords instead of framework type names for type references
dotnet_style_predefined_type_for_locals_parameters_members = true:warning
dotnet_style_predefined_type_for_member_access = true:warning
# Modifier preferences
dotnet_style_require_accessibility_modifiers = always:warning
csharp_preferred_modifier_order = public,private,protected,internal,static,extern,new,virtual,abstract,sealed,override,readonly,unsafe,volatile,async:warning
visual_basic_preferred_modifier_order = Partial,Default,Private,Protected,Public,Friend,NotOverridable,Overridable,MustOverride,Overloads,Overrides,MustInherit,NotInheritable,Static,Shared,Shadows,ReadOnly,WriteOnly,Dim,Const,WithEvents,Widening,Narrowing,Custom,Async:warning
dotnet_style_readonly_field = true:warning
# Parentheses preferences
dotnet_style_parentheses_in_arithmetic_binary_operators = always_for_clarity:warning
dotnet_style_parentheses_in_relational_binary_operators = always_for_clarity:warning
dotnet_style_parentheses_in_other_binary_operators = always_for_clarity:warning
dotnet_style_parentheses_in_other_operators = never_if_unnecessary:warning
# Expression-level preferences
dotnet_style_object_initializer = true:warning
dotnet_style_collection_initializer = true:warning
dotnet_style_explicit_tuple_names = true:warning
dotnet_style_prefer_inferred_tuple_names = true:warning
dotnet_style_prefer_inferred_anonymous_type_member_names = true:warning
dotnet_style_prefer_auto_properties = true:warning
dotnet_style_prefer_conditional_expression_over_assignment = true:suggestion
dotnet_diagnostic.IDE0045.severity = suggestion
dotnet_style_prefer_conditional_expression_over_return = false:suggestion
dotnet_diagnostic.IDE0046.severity = suggestion
dotnet_style_prefer_compound_assignment = true:warning
dotnet_style_prefer_simplified_interpolation = true:warning
dotnet_style_prefer_simplified_boolean_expressions = true:warning
# Null-checking preferences
dotnet_style_coalesce_expression = true:warning
dotnet_style_null_propagation = true:warning
dotnet_style_prefer_is_null_check_over_reference_equality_method = true:warning
# File header preferences
# file_header_template = <copyright file="{fileName}" company="PROJECT-AUTHOR">\n© PROJECT-AUTHOR\n</copyright>
# If you use StyleCop, you'll need to disable SA1636: File header copyright text should match.
# dotnet_diagnostic.SA1636.severity = none
# Undocumented
dotnet_style_operator_placement_when_wrapping = end_of_line:warning
csharp_style_prefer_null_check_over_type_check = true:warning

# C# Style Rules
# https://docs.microsoft.com/dotnet/fundamentals/code-analysis/style-rules/language-rules#c-style-rules
[*.{cs,csx,cake}]
# 'var' preferences
csharp_style_var_for_built_in_types = true:warning
csharp_style_var_when_type_is_apparent = true:warning
csharp_style_var_elsewhere = true:warning
# Expression-bodied members
csharp_style_expression_bodied_methods = true:warning
csharp_style_expression_bodied_constructors = false:warning
csharp_style_expression_bodied_operators = true:warning
csharp_style_expression_bodied_properties = true:warning
csharp_style_expression_bodied_indexers = true:warning
csharp_style_expression_bodied_accessors = true:warning
csharp_style_expression_bodied_lambdas = true:warning
csharp_style_expression_bodied_local_functions = true:warning
# Pattern matching preferences
csharp_style_pattern_matching_over_is_with_cast_check = true:warning
csharp_style_pattern_matching_over_as_with_null_check = true:warning
csharp_style_prefer_switch_expression = true:warning
csharp_style_prefer_pattern_matching = true:warning
csharp_style_prefer_not_pattern = true:warning
# Expression-level preferences
csharp_style_inlined_variable_declaration = true:warning
csharp_prefer_simple_default_expression = true:warning
csharp_style_pattern_local_over_anonymous_function = true:warning
csharp_style_deconstructed_variable_declaration = true:warning
csharp_style_prefer_index_operator = true:warning
csharp_style_prefer_range_operator = true:warning
csharp_style_implicit_object_creation_when_type_is_apparent = true:warning
# "Null" checking preferences
csharp_style_throw_expression = true:warning
csharp_style_conditional_delegate_call = true:warning
# Code block preferences
csharp_prefer_braces = true:warning
csharp_prefer_simple_using_statement = true:suggestion
dotnet_diagnostic.IDE0063.severity = suggestion
# 'using' directive preferences
csharp_using_directive_placement = outside_namespace:warning
# Modifier preferences
csharp_prefer_static_local_function = true:warning

##########################################
# Unnecessary Code Rules
# https://docs.microsoft.com/dotnet/fundamentals/code-analysis/style-rules/unnecessary-code-rules
##########################################

# .NET Unnecessary code rules
[*.{cs,csx,cake,vb,vbx}]
dotnet_code_quality_unused_parameters = all:warning
dotnet_remove_unnecessary_suppression_exclusions = none:warning

# C# Unnecessary code rules
[*.{cs,csx,cake}]
csharp_style_unused_value_expression_statement_preference = discard_variable:suggestion
dotnet_diagnostic.IDE0058.severity = suggestion
csharp_style_unused_value_assignment_preference = discard_variable:suggestion
dotnet_diagnostic.IDE0059.severity = suggestion

##########################################
# Formatting Rules
# https://docs.microsoft.com/dotnet/fundamentals/code-analysis/style-rules/formatting-rules
##########################################

# .NET formatting rules
# https://docs.microsoft.com/dotnet/fundamentals/code-analysis/style-rules/formatting-rules#net-formatting-rules
[*.{cs,csx,cake,vb,vbx}]
# Organize using directives
dotnet_sort_system_directives_first = true
dotnet_separate_import_directive_groups = false
# Dotnet namespace options
dotnet_style_namespace_match_folder = true:suggestion
dotnet_diagnostic.IDE0130.severity = suggestion

# C# formatting rules
# https://docs.microsoft.com/dotnet/fundamentals/code-analysis/style-rules/formatting-rules#c-formatting-rules
[*.{cs,csx,cake}]
# Newline options
# https://docs.microsoft.com/dotnet/fundamentals/code-analysis/style-rules/formatting-rules#new-line-options
csharp_new_line_before_open_brace = all
csharp_new_line_before_else = true
csharp_new_line_before_catch = true
csharp_new_line_before_finally = true
csharp_new_line_before_members_in_object_initializers = true
csharp_new_line_before_members_in_anonymous_types = true
csharp_new_line_between_query_expression_clauses = true
# Indentation options
# https://docs.microsoft.com/dotnet/fundamentals/code-analysis/style-rules/formatting-rules#indentation-options
csharp_indent_case_contents = true
csharp_indent_switch_labels = true
csharp_indent_labels = no_change
csharp_indent_block_contents = true
csharp_indent_braces = false
csharp_indent_case_contents_when_block = false
# Spacing options
# https://docs.microsoft.com/dotnet/fundamentals/code-analysis/style-rules/formatting-rules#spacing-options
csharp_space_after_cast = false
csharp_space_after_keywords_in_control_flow_statements = true
csharp_space_between_parentheses = false
csharp_space_before_colon_in_inheritance_clause = true
csharp_space_after_colon_in_inheritance_clause = true
csharp_space_around_binary_operators = before_and_after
csharp_space_between_method_declaration_parameter_list_parentheses = false
csharp_space_between_method_declaration_empty_parameter_list_parentheses = false
csharp_space_between_method_declaration_name_and_open_parenthesis = false
csharp_space_between_method_call_parameter_list_parentheses = false
csharp_space_between_method_call_empty_parameter_list_parentheses = false
csharp_space_between_method_call_name_and_opening_parenthesis = false
csharp_space_after_comma = true
csharp_space_before_comma = false
csharp_space_after_dot = false
csharp_space_before_dot = false
csharp_space_after_semicolon_in_for_statement = true
csharp_space_before_semicolon_in_for_statement = false
csharp_space_around_declaration_statements = false
csharp_space_before_open_square_brackets = false
csharp_space_between_empty_square_brackets = false
csharp_space_between_square_brackets = false
# Wrap options
# https://docs.microsoft.com/dotnet/fundamentals/code-analysis/style-rules/formatting-rules#wrap-options
csharp_preserve_single_line_statements = false
csharp_preserve_single_line_blocks = true
# Namespace options
# https://docs.microsoft.com/dotnet/fundamentals/code-analysis/style-rules/formatting-rules#namespace-options
csharp_style_namespace_declarations = file_scoped:warning

##########################################
# .NET Naming Rules
# https://docs.microsoft.com/dotnet/fundamentals/code-analysis/style-rules/naming-rules
##########################################

[*.{cs,csx,cake,vb,vbx}]

##########################################
# Styles
##########################################

# camel_case_style - Define the camelCase style
dotnet_naming_style.camel_case_style.capitalization = camel_case
# pascal_case_style - Define the PascalCase style
dotnet_naming_style.pascal_case_style.capitalization = pascal_case
# first_upper_style - The first character must start with an upper-case character
dotnet_naming_style.first_upper_style.capitalization = first_word_upper
# prefix_interface_with_i_style - Interfaces must be PascalCase and the first character of an interface must be an 'I'
dotnet_naming_style.prefix_interface_with_i_style.capitalization = pascal_case
dotnet_naming_style.prefix_interface_with_i_style.required_prefix = I
# prefix_type_parameters_with_t_style - Generic Type Parameters must be PascalCase and the first character must be a 'T'
dotnet_naming_style.prefix_type_parameters_with_t_style.capitalization = pascal_case
dotnet_naming_style.prefix_type_parameters_with_t_style.required_prefix = T
# disallowed_style - Anything that has this style applied is marked as disallowed
dotnet_naming_style.disallowed_style.capitalization  = pascal_case
dotnet_naming_style.disallowed_style.required_prefix = ____RULE_VIOLATION____
dotnet_naming_style.disallowed_style.required_suffix = ____RULE_VIOLATION____
# internal_error_style - This style should never occur... if it does, it indicates a bug in file or in the parser using the file
dotnet_naming_style.internal_error_style.capitalization  = pascal_case
dotnet_naming_style.internal_error_style.required_prefix = ____INTERNAL_ERROR____
dotnet_naming_style.internal_error_style.required_suffix = ____INTERNAL_ERROR____

##########################################
# .NET Design Guideline Field Naming Rules
# Naming rules for fields follow the .NET Framework design guidelines
# https://docs.microsoft.com/dotnet/standard/design-guidelines/index
##########################################

# All public/protected/protected_internal constant fields must be PascalCase
# https://docs.microsoft.com/dotnet/standard/design-guidelines/field
dotnet_naming_symbols.public_protected_constant_fields_group.applicable_accessibilities = public, protected, protected_internal
dotnet_naming_symbols.public_protected_constant_fields_group.required_modifiers         = const
dotnet_naming_symbols.public_protected_constant_fields_group.applicable_kinds           = field
dotnet_naming_rule.public_protected_constant_fields_must_be_pascal_case_rule.symbols    = public_protected_constant_fields_group
dotnet_naming_rule.public_protected_constant_fields_must_be_pascal_case_rule.style      = pascal_case_style
dotnet_naming_rule.public_protected_constant_fields_must_be_pascal_case_rule.severity   = warning

# All public/protected/protected_internal static readonly fields must be PascalCase
# https://docs.microsoft.com/dotnet/standard/design-guidelines/field
dotnet_naming_symbols.public_protected_static_readonly_fields_group.applicable_accessibilities = public, protected, protected_internal
dotnet_naming_symbols.public_protected_static_readonly_fields_group.required_modifiers         = static, readonly
dotnet_naming_symbols.public_protected_static_readonly_fields_group.applicable_kinds           = field
dotnet_naming_rule.public_protected_static_readonly_fields_must_be_pascal_case_rule.symbols    = public_protected_static_readonly_fields_group
dotnet_naming_rule.public_protected_static_readonly_fields_must_be_pascal_case_rule.style      = pascal_case_style
dotnet_naming_rule.public_protected_static_readonly_fields_must_be_pascal_case_rule.severity   = warning

# No other public/protected/protected_internal fields are allowed
# https://docs.microsoft.com/dotnet/standard/design-guidelines/field
dotnet_naming_symbols.other_public_protected_fields_group.applicable_accessibilities = public, protected, protected_internal
dotnet_naming_symbols.other_public_protected_fields_group.applicable_kinds           = field
dotnet_naming_rule.other_public_protected_fields_disallowed_rule.symbols             = other_public_protected_fields_group
dotnet_naming_rule.other_public_protected_fields_disallowed_rule.style               = disallowed_style
dotnet_naming_rule.other_public_protected_fields_disallowed_rule.severity            = error

##########################################
# StyleCop Field Naming Rules
# Naming rules for fields follow the StyleCop analyzers
# This does not override any rules using disallowed_style above
# https://github.com/DotNetAnalyzers/StyleCopAnalyzers
##########################################

# All constant fields must be PascalCase
# https://github.com/DotNetAnalyzers/StyleCopAnalyzers/blob/master/documentation/SA1303.md
dotnet_naming_symbols.stylecop_constant_fields_group.applicable_accessibilities = public, internal, protected_internal, protected, private_protected, private
dotnet_naming_symbols.stylecop_constant_fields_group.required_modifiers         = const
dotnet_naming_symbols.stylecop_constant_fields_group.applicable_kinds           = field
dotnet_naming_rule.stylecop_constant_fields_must_be_pascal_case_rule.symbols    = stylecop_constant_fields_group
dotnet_naming_rule.stylecop_constant_fields_must_be_pascal_case_rule.style      = pascal_case_style
dotnet_naming_rule.stylecop_constant_fields_must_be_pascal_case_rule.severity   = warning

# All static readonly fields must be PascalCase
# https://github.com/DotNetAnalyzers/StyleCopAnalyzers/blob/master/documentation/SA1311.md
dotnet_naming_symbols.stylecop_static_readonly_fields_group.applicable_accessibilities = public, internal, protected_internal, protected, private_protected, private
dotnet_naming_symbols.stylecop_static_readonly_fields_group.required_modifiers         = static, readonly
dotnet_naming_symbols.stylecop_static_readonly_fields_group.applicable_kinds           = field
dotnet_naming_rule.stylecop_static_readonly_fields_must_be_pascal_case_rule.symbols    = stylecop_static_readonly_fields_group
dotnet_naming_rule.stylecop_static_readonly_fields_must_be_pascal_case_rule.style      = pascal_case_style
dotnet_naming_rule.stylecop_static_readonly_fields_must_be_pascal_case_rule.severity   = warning

# No non-private instance fields are allowed
# https://github.com/DotNetAnalyzers/StyleCopAnalyzers/blob/master/documentation/SA1401.md
dotnet_naming_symbols.stylecop_fields_must_be_private_group.applicable_accessibilities = public, internal, protected_internal, protected, private_protected
dotnet_naming_symbols.stylecop_fields_must_be_private_group.applicable_kinds           = field
dotnet_naming_rule.stylecop_instance_fields_must_be_private_rule.symbols               = stylecop_fields_must_be_private_group
dotnet_naming_rule.stylecop_instance_fields_must_be_private_rule.style                 = disallowed_style
dotnet_naming_rule.stylecop_instance_fields_must_be_private_rule.severity              = error

# Private fields must be camelCase
# https://github.com/DotNetAnalyzers/StyleCopAnalyzers/blob/master/documentation/SA1306.md
dotnet_naming_symbols.stylecop_private_fields_group.applicable_accessibilities = private
dotnet_naming_symbols.stylecop_private_fields_group.applicable_kinds           = field
dotnet_naming_rule.stylecop_private_fields_must_be_camel_case_rule.symbols     = stylecop_private_fields_group
dotnet_naming_rule.stylecop_private_fields_must_be_camel_case_rule.style       = camel_case_style
dotnet_naming_rule.stylecop_private_fields_must_be_camel_case_rule.severity    = warning

# Local variables must be camelCase
# https://github.com/DotNetAnalyzers/StyleCopAnalyzers/blob/master/documentation/SA1312.md
dotnet_naming_symbols.stylecop_local_fields_group.applicable_accessibilities = local
dotnet_naming_symbols.stylecop_local_fields_group.applicable_kinds           = local
dotnet_naming_rule.stylecop_local_fields_must_be_camel_case_rule.symbols     = stylecop_local_fields_group
dotnet_naming_rule.stylecop_local_fields_must_be_camel_case_rule.style       = camel_case_style
dotnet_naming_rule.stylecop_local_fields_must_be_camel_case_rule.severity    = silent

# This rule should never fire.  However, it's included for at least two purposes:
# First, it helps to understand, reason about, and root-case certain types of issues, such as bugs in .editorconfig parsers.
# Second, it helps to raise immediate awareness if a new field type is added (as occurred recently in C#).
dotnet_naming_symbols.sanity_check_uncovered_field_case_group.applicable_accessibilities = *
dotnet_naming_symbols.sanity_check_uncovered_field_case_group.applicable_kinds           = field
dotnet_naming_rule.sanity_check_uncovered_field_case_rule.symbols  = sanity_check_uncovered_field_case_group
dotnet_naming_rule.sanity_check_uncovered_field_case_rule.style    = internal_error_style
dotnet_naming_rule.sanity_check_uncovered_field_case_rule.severity = error


##########################################
# Other Naming Rules
##########################################

# All of the following must be PascalCase:
# - Namespaces
#   https://docs.microsoft.com/dotnet/standard/design-guidelines/names-of-namespaces
#   https://github.com/DotNetAnalyzers/StyleCopAnalyzers/blob/master/documentation/SA1300.md
# - Classes and Enumerations
#   https://docs.microsoft.com/dotnet/standard/design-guidelines/names-of-classes-structs-and-interfaces
#   https://github.com/DotNetAnalyzers/StyleCopAnalyzers/blob/master/documentation/SA1300.md
# - Delegates
#   https://docs.microsoft.com/dotnet/standard/design-guidelines/names-of-classes-structs-and-interfaces#names-of-common-types
# - Constructors, Properties, Events, Methods
#   https://docs.microsoft.com/dotnet/standard/design-guidelines/names-of-type-members
dotnet_naming_symbols.element_group.applicable_kinds = namespace, class, enum, struct, delegate, event, method, property
dotnet_naming_rule.element_rule.symbols              = element_group
dotnet_naming_rule.element_rule.style                = pascal_case_style
dotnet_naming_rule.element_rule.severity             = warning

# Interfaces use PascalCase and are prefixed with uppercase 'I'
# https://docs.microsoft.com/dotnet/standard/design-guidelines/names-of-classes-structs-and-interfaces
dotnet_naming_symbols.interface_group.applicable_kinds = interface
dotnet_naming_rule.interface_rule.symbols              = interface_group
dotnet_naming_rule.interface_rule.style                = prefix_interface_with_i_style
dotnet_naming_rule.interface_rule.severity             = warning

# Generics Type Parameters use PascalCase and are prefixed with uppercase 'T'
# https://docs.microsoft.com/dotnet/standard/design-guidelines/names-of-classes-structs-and-interfaces
dotnet_naming_symbols.type_parameter_group.applicable_kinds = type_parameter
dotnet_naming_rule.type_parameter_rule.symbols              = type_parameter_group
dotnet_naming_rule.type_parameter_rule.style                = prefix_type_parameters_with_t_style
dotnet_naming_rule.type_parameter_rule.severity             = warning

# Function parameters use camelCase
# https://docs.microsoft.com/dotnet/standard/design-guidelines/naming-parameters
dotnet_naming_symbols.parameters_group.applicable_kinds = parameter
dotnet_naming_rule.parameters_rule.symbols              = parameters_group
dotnet_naming_rule.parameters_rule.style                = camel_case_style
dotnet_naming_rule.parameters_rule.severity             = warning

# Define the 'private_fields' symbol group:
dotnet_naming_symbols.private_fields.applicable_kinds = field
dotnet_naming_symbols.private_fields.applicable_accessibilities = private

# Define the 'private_static_fields' symbol group
dotnet_naming_symbols.private_static_fields.applicable_kinds = field
dotnet_naming_symbols.private_static_fields.applicable_accessibilities = private
dotnet_naming_symbols.private_static_fields.required_modifiers = static

# Define the 'private_readonly_fields' symbol group
dotnet_naming_symbols.private_readonly_fields.applicable_kinds = field
dotnet_naming_symbols.private_readonly_fields.applicable_accessibilities = private
dotnet_naming_symbols.private_readonly_fields.required_modifiers = readonly

# Define the 'underscored' naming style
dotnet_naming_style.underscored.capitalization = camel_case
dotnet_naming_style.underscored.required_prefix = _

# Define the 'private_fields_underscored' naming rule
dotnet_naming_rule.private_fields_underscored.symbols = private_fields
dotnet_naming_rule.private_fields_underscored.style = underscored
dotnet_naming_rule.private_fields_underscored.severity = error

# Define the 'private_readonly_fields_underscored' naming rule
dotnet_naming_rule.private_readonly_fields_underscored.symbols = private_readonly_fields
dotnet_naming_rule.private_readonly_fields_underscored.style = underscored
dotnet_naming_rule.private_readonly_fields_underscored.severity = error

# Define the 'private_static_fields_none' naming rule
dotnet_naming_rule.private_static_fields_none.symbols = private_static_fields
dotnet_naming_rule.private_static_fields_none.style = underscored
dotnet_naming_rule.private_static_fields_none.severity = none