Update .editorconfig file with improved syntax to support IDEs and MSBuild

[alexandrejobin]

Hi everyone!

I needed to have an editorconfig file to apply code styling that would be respected by any IDE and also by the MSBuild. The goal was that if you do not respect the rules, whatever tool that you use to edit the files, MSBuild would alert us with a list of warnings and errors.

By reading about this subject on the web, I came accross the article C# code style by EditorConfig in .NET 5 SDK and beyond that explain the different syntaxes that we should use and how they affect the IDE and MSBuild. By using option_name = option_value:severity syntax, only IDEs recognise it. MSBuild will only honor the dotnet_diagnostic.RULEID.severity syntax so we have to mix the two syntaxes. You also have to add the EnforceCodeStyleInBuild = true config to each .csproj files.

So here's a glimpse of what I did for my projects. I would like your thoughts on this and if it would be good to include it in the template.

For exemple, dotnet_style_qualification_for_field = false is the default value taken from Microsoft online doc and then I use dotnet_diagnostic.IDE0003.severity = default to tell to use the default severity if the rules is not respected.

###############################
# C# Style Rules
# https://learn.microsoft.com/en-us/dotnet/fundamentals/code-analysis/style-rules/
###############################
[*.{cs}]

# "this." preferences
# https://learn.microsoft.com/en-us/dotnet/fundamentals/code-analysis/style-rules/ide0003-ide0009
dotnet_style_qualification_for_field = false
dotnet_style_qualification_for_property = false
dotnet_style_qualification_for_method = false
dotnet_style_qualification_for_event = false
dotnet_diagnostic.IDE0003.severity = default
dotnet_diagnostic.IDE0009.severity = default

# Remove unnecessary using directives
# https://learn.microsoft.com/en-us/dotnet/fundamentals/code-analysis/style-rules/ide0005
dotnet_diagnostic.IDE0005.severity = default

# 'var' preferences
# https://learn.microsoft.com/en-us/dotnet/fundamentals/code-analysis/style-rules/ide0007-ide0008
csharp_style_var_for_built_in_types = false
csharp_style_var_when_type_is_apparent = false
csharp_style_var_elsewhere = false
dotnet_diagnostic.IDE0007.severity = default
dotnet_diagnostic.IDE0008.severity = default

# Add missing cases to switch statement
# https://learn.microsoft.com/en-us/dotnet/fundamentals/code-analysis/style-rules/ide0010
dotnet_diagnostic.IDE0010.severity = default

# Add braces
# https://learn.microsoft.com/en-us/dotnet/fundamentals/code-analysis/style-rules/ide0011
csharp_prefer_braces = true
dotnet_diagnostic.IDE0011.severity = warning

# Use throw expression
# https://learn.microsoft.com/en-us/dotnet/fundamentals/code-analysis/style-rules/ide0016
csharp_style_throw_expression = true
dotnet_diagnostic.IDE0016.severity = default

...