Category: FileExtension

FileExtension–PostMortem- part 7

It was interesting to wrote this project.  At the final, it features an web site (https://fileextension.azurewebsites.net/ ) and a NuGet package ( https://www.nuget.org/packages/FileExtension/ ). Also , I have learned how to start Windows Terminal to start Angular / .NET Core / Tests

wt new-tab -p “Windows PowerShell” -d . cmd /k “cd src && dotnet build && cd RecognizeFileExtWebAPI && dotnet watch run”  ;split-pane -p “Windows PowerShell” -d . cmd /k “cd src && dotnet build && cd TestFileExtensions && dotnet watch test” ;  split-pane -p “Windows PowerShell” -d . cmd /k “cd src && cd FileExtensionAng && npm i && ng serve -o”

and refreshed my GitHub actions knowledge ( I am very fond of CI – and , if I can, CD )

Also, I have now a better understanding of a csproj file in relation with nuget :

<ItemGroup>
   <None Remove=”plugins\FileExtension.targets” />
<Content Include=”plugins\FileExtension.targets”>
   <PackagePath>build\net5.0\</PackagePath>
   <CopyToOutputDirectory>PreserveNewest</CopyToOutputDirectory>
</Content>
</ItemGroup>

<ItemGroup>
   <Content Include=”plugins\**\*.dll”>
     <PackagePath>build\net5.0\plugins\</PackagePath>
     <CopyToOutputDirectory>PreserveNewest</CopyToOutputDirectory>
   </Content>
</ItemGroup>

It was refreshing to know that, even I like the Skinny Controllers concept, however the WebAPI is not so light .

Hopefully someone will find the package useful – or at least the site  https://fileextension.azurewebsites.net/

FileExtension–part 6 – CI/CD

So now how to make visible all those coding ?

For tests –CodeCov,  https://app.codecov.io/gh/ignatandrei/FileExtension hosts for free to see the coverage

For documentation – ReadTheDocs,  https://fileextension.readthedocs.io/en/latest/ hosts for free.

For packaging  – NuGEt https://www.nuget.org/packages/FileExtension/

For more detailed analysis Sonar https://sonarcloud.io/summary/overall?id=ignatandrei_FileExtension can show code smells and bugs and more

GitHub actions https://github.com/ignatandrei/FileExtension/actions allows me to run all those automatically and gather results

For showing a website – Azure  – https://fileextension.azurewebsites.net/ can show the usage.

I was thinking that it is enough for the people to understand the application

FileExtension–Tests–part 5

The tests are the easy part. I have put some files on a folder( https://github.com/ignatandrei/FileExtension/tree/master/src/TestFileExtensions/TestFiles ) and test if the extension matches the recognizer.

As NuGet packages I used

FluentAssertions

xunit

LightBDD.XUnit2

FluentAssertion allows me to write more readable tests , like 

AllExtensions.Should().HaveCountGreaterThanOrEqualTo(number);

LightBDD allows me to write tests in a more “business “ way :

await Runner
     .AddSteps(Given_The_Recognizer)
     .AddAsyncSteps(_ => When_Read_The_File(fileName))
     .AddSteps(
         _ => Then_Should_Recognize_File(fileName),
         _ => Then_The_Extension_Matches(fileName)
     )
     .RunAsync();

You can see the result at https://fileextension.readthedocs.io/en/latest/BDD/LightBDDReport/ = go down to see the Given / When /

Also, for enumerating files from the folder to test, I use ClassData

[ClassData(typeof(DirectoryTestData))]
public async void TestMultipleFiles(string nameFile)

FileExtension – GUI–part 4

Now I must do something for the people that just want to use the software. The most usual , for me, it is a .NET Core WebAPI site ( with swagger ) and an Angular frontend.

You can find the sources at https://github.com/ignatandrei/FileExtension/tree/master/src . Some thoughts:

For .NET Core ( see https://github.com/ignatandrei/FileExtension/tree/master/src/RecognizeFileExtWebAPI ) I use the following NuGET packages ( other than usual .NET Core)

Microsoft.AspNetCore.Mvc.Versioning

Microsoft.AspNetCore.Mvc.Versioning.ApiExplorer

Swashbuckle.AspNetCore

Hellang.Middleware.ProblemDetails

AMSWebAPI

AMS_Base

RSCG_AMS

The final result can be seen at https://fileextension.azurewebsites.net/swagger

For Angular( https://github.com/ignatandrei/FileExtension/tree/master/src/FileExtensionAng) I use the following packages( other than usual Angular)

@angular/material

angular-shepherd

The final result can be seen at https://fileextension.azurewebsites.net/

FileExtension–plugins–part 3

What I have more in mind is that the people can add easy their code for extensions.

That means:

  1. Have an easy class to add the magic number in the header for an extension
  2. Have other people add their own implementations, not just the header
  3. Have an easy way to add the project with their code

 

First item it is easy – just create a class RecognizeFirstBytes and pass into constructor the first bytes

As an example , see the sln implementation


    public class RecognizeSln : RecognizeFirstBytes
    {
        public RecognizeSln() : base("EFBBBF0D0A4D6963726F736F66742056697375616C2053747564696F20536F6C7574696F6E2046696C65")
        {
            Extension = new string[1] { "sln" };
        }
    }

The second item can be implemented with an interface IRecognize


    public interface IRecognize: IEquatable<IRecognize>
    {
        Result InfoNeeded(byte[] b=null);
        string[] Extension { get; set; }
    }

The third item can be made by  making a third project  that  either references all other projects, either loading others as plugins . Because of the experience, I choose the most interesting one – plugins. I need first https://github.com/natemcmaster/DotNetCorePlugins . Second I need the plugins to be copied – I use a Target

  <Target Name="PreBuild" BeforeTargets="PreBuildEvent">
    <Exec Command="xcopy &quot;$(ProjectDir)../plugins/*.dll&quot; &quot;$(ProjectDir)plugins&quot; /E /F /I /Y /R" />
  </Target>

And last I need this plugin loader , when packed as nuget  at https://www.nuget.org/packages/FileExtension/ , to have also the plugins – for this I use the csproj

<ItemGroup>
  <Content Include="plugins\**\*.dll">
    <PackagePath>build\net5.0\plugins\</PackagePath>
    <CopyToOutputDirectory>PreserveNewest</CopyToOutputDirectory>
  </Content>
</ItemGroup>

FileExtension– export data from CSV–part 2

First, is how to export data from table (https://en.wikipedia.org/wiki/List_of_file_signatures) into classes . First, the table must be transformed into a more programmatic recognizable way – like a CSV  – see https://github.com/ignatandrei/FileExtension/blob/master/src/RSCG_GCK/offset0.txt

Then a solution is to have into the dll ( as embedded resource or as a file) . The second solution, more complicated , is to use Roslyn Source Code Generators to generate the classes for each element of the CSV .

I’d liked more the second solution – the sources are at https://github.com/ignatandrei/FileExtension/tree/master/src/RSCG_GCK 

What it generates is like this

namespace RecognizeCustomSigs_GCK {
    class RecognizeFromGCKLine0_JP2: RecognizeFromLineCustomsigs{
        public RecognizeFromGCKLine0_JP2(): base("JPEG2000 image files,00 00 00 0C 6A 50 20 20,JP2")                
        {
        }
    }
}

FileExtension–idea- part 1

Every now and then we accept file uploads ( to a site  ) – or we have files in outlook that we want to open – but we do not know if the extension matches the content of the file.

There are numerous way to do it , however , I have been attracted by Magic Numbers – a header into the file that says what is the kind of the file.

For example, a .sln file has always those characters inside:

Microsoft Visual Studio Solution File, Format Version

You can then recognize if it is a real sln if it contains those characters.

Reading more on the internet, I have found

https://www.garykessler.net/library/file_sigs.html

https://en.wikipedia.org/wiki/Magic_number_(programming)#Magic_numbers_in_files

https://en.wikipedia.org/wiki/List_of_file_signatures

Now, there are multiple programs and sites to do this magic number verifier – however, in order to practice programming, is always a good idea to start somewhere – so let’s see where it goes.

You can find the sources at https://github.com/ignatandrei/fileExtension/

The application is live at https://fileextension.azurewebsites.net/static/v1

You can find a NuGet package at https://www.nuget.org/packages/FileExtension/

Andrei Ignat weekly software news(mostly .NET)

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