How to share source code via NuGet packages for use in .NET Core projects

Question

I want to make small pieces of source code (e.g. helper classes) available for use in .NET Core projects (.csproj). At this point I packaged the source code with NuGet in many different ways according to different blog posts and the official nuget docs. I used a nuspec file to control where my source files will end up in the nuget package, e.g.:

<files>
    <file src="*.cs" target="content/LruCache" />
    <file src="*.cs" target="contentFiles/cs/any/LruCache" />
</files>

I did not include any msbuild targets file or install script.

Whenever I install the NuGet package into a .NET Core project (https://docs.microsoft.com/en-us/dotnet/core/tools/csproj) I simply don't get anything there. No source files will be included into my project. I tried different settings for the <PackageReference/> node in the .csproj (PrivateAssets, etc.) without success.

Is it meant to be possible at all? If so, how should it be done?

---

Background:
The reason for doing this is some kind of diamond problem where we have projects B and C both using helper class A and a third project D using B and C. In this situation I don't want to deal with assembly version conflicts when different (incompatible) versions of A have been used in B and C.

Answer 1

Is it meant to be possible at all? If so, how should it be done?

The answer is yes. Since you test project type is .net core. You should use contentFiles instead of content. content is used for packages.config. Check the Using the contentFiles element for content files and blog NuGet ContentFiles Demystified for more details.

So your .nuspec file should be:

<?xml version="1.0" encoding="utf-8"?>
<package xmlns="http://schemas.microsoft.com/packaging/2011/08/nuspec.xsd">
  <metadata>
    <id>MyTestCore</id>
    <version>5.0.0</version>
    <authors>TestContentFile</authors>
    <owners>TestContentFile</owners>
    <requireLicenseAcceptance>false</requireLicenseAcceptance>
    <description>Package Description</description>
    <contentFiles>
      <files include="any/any/Test.cs" buildAction="content" flatten="true" copyToOutput="true"/>
    </contentFiles>
  </metadata>

  <files>
    <file src="contentFiles/any/any/Test.cs" target="contentFiles/any/any/LruCache" />
  </files>
</package>

The nuget package should be looks like:

Note: When you create a new package, do not forgot to remove the nuget cache for this package in the C:\Users\<UserName>\.nuget\packages folder, otherwise, it always install the old package.

With this method, the source files will be included into your project.

Hope this helps.