To global using directive refactoring

Question

I would like to migrate my projects to .NET 6 and C# 10. As a part of this migration I would like to use global using directives.

Has Visual Studio 2022 any tool or help to do a "to global using directive" refactoring?

Prasad Telkikar · Answer 1 · 2021-11-16T12:54:14.923

2

I don't think, there is any tool which does "To global using" directive refactoring, but you can try alternate way,

Replace using block with empty string in entire project, you can use Ctrl + Shift + H

Now you can add global using in any .cs file or you put all global using in a separate file called globalusings.cs

Note:

Find + Replace will add additional empty line in all .cs files.

edited Nov 16 '21 at 12:54

answered Nov 16 '21 at 07:03

Prasad Telkikar

15,207
5
21
44

score 2 · Answer 2 · answered Nov 16 '21 at 08:33

2

Making namespace global should render corresponding using unnecessary in other files. Remove unnecessary usings diagnostic allows you to select the scope for the fix:

If for some reason the diagnostic is not shown you can enable it via .editorconfig via rule code (IDE0005):

# IDE0005: Using directive is unnecessary.
dotnet_diagnostic.IDE0005.severity = suggestion

answered Nov 16 '21 at 08:33

Guru Stron

102,774
10
95
132

Many thx, that is a good idea, but the half of the story, I mean we must create the global usings manually. You are right, then a using directive removal cleanup (either VS build in via editorconfig, or 3rd party) will do the heavy lifting. – g.pickardou Nov 17 '21 at 06:55
@guru-stron Do you know when a using statement should be kept in a file instead of moved to `globalusings.cs`? Is there an advantage to not move everything into `globalusings.cs`? – surfmuggle Feb 06 '23 at 07:51
@surfmuggle you mean global usings? – Guru Stron Feb 06 '23 at 07:57
@guru-stron Yes. Are there any advantages to declare a `using foo.bar` statement as a global using statement and move it from `n` files to a central `globalusings.cs` other than to not have this `using foo.bar` in `n` files? – surfmuggle Feb 06 '23 at 08:05
@surfmuggle oh, you mean `using` vs `global using` (personally I even prefer adding `Using` xml element into csproj instead of `global using` in some file). The main advantage - reducing number of code lines with corresponding benefits - some are described in [this answer](https://stackoverflow.com/a/75170889/2501279). Despite IDEs being able to reduce the clutter of working with namespaces still there is some (and you do not always work with IDE - for example when looking at the diff in the github). – Guru Stron Feb 06 '23 at 08:28

score 2 · Answer 3 · answered Jan 27 '22 at 11:25

I've just faced to the same problem and wrote simple console application to solve this problem.

using System.Text;

if (args.Length == 0 || string.IsNullOrEmpty(args[0]))
    throw new ArgumentException("You must specify directory");
var directoryForScan = args[0];
if (!Directory.Exists(directoryForScan))
{
    throw new ArgumentException($"{directoryForScan} not exist");
}

var filesEnumeration = Directory.EnumerateFiles(directoryForScan, "*.cs", SearchOption.AllDirectories);
var directorySeparator = Path.DirectorySeparatorChar;
var usingSet = new SortedSet<string>(StringComparer.OrdinalIgnoreCase);
foreach (var filePath in filesEnumeration.Where(it => !it.Contains($"{directorySeparator}bin{directorySeparator}") 
                                                  && !it.Contains($"{directorySeparator}obj{directorySeparator}")))
{
    await ProcessUsingAsync(filePath, usingSet);
}

var resultFilePath = Path.Combine(directoryForScan,"GlobalUsings.cs");

await using var resultStream = new FileStream(resultFilePath, FileMode.Create, FileAccess.Write, FileShare.Write);
await using var writer = new StreamWriter(resultStream, Encoding.UTF8);
foreach (var item in usingSet)
{
    Console.WriteLine(item);
    await writer.WriteAsync("global ");
    await writer.WriteLineAsync(item);
}

await resultStream.FlushAsync();

static async Task ProcessUsingAsync(string filePath, ISet<string> usingSet)
{
    await using var fileStream = File.OpenRead(filePath);
    using var reader = new StreamReader(fileStream);
    string? currentLine;
    do
    {
        currentLine = await reader.ReadLineAsync();
        if (currentLine is not null 
            && currentLine.StartsWith("using")
            && currentLine.EndsWith(";") 
            && !currentLine.Contains(" static ") 
            && !currentLine.Contains("="))
        {
            usingSet.Add(currentLine);
        }
    } while (currentLine != null);
}

score 2 · Accepted Answer · answered Dec 13 '22 at 12:08

2

ReSharper/Jetbrains is again one step ahead with it's 'Extract Global Using refactoring'.

If you want to know more about it https://www.jetbrains.com/help/resharper/Refactorings__Extract_Global_Using.html

answered Dec 13 '22 at 12:08

Lukáš Kmoch

1,239
11
11

To global using directive refactoring

4 Answers4