c# - How to add and use an import in a script?

Question

In the following code I need to add my assembly so that the script can make use of its classes:

var options = ScriptOptions.Default.AddImports("MyAssembly");

var code = "using MyAssembly.MyNamespace;" +
           "public class TestClass {" +
           "  public int HelloWorld(int num) {" +
           "    return 5 + num;" +
           "  }" +
           "}";

But the following exception is thrown:

Exception thrown: 'Microsoft.CodeAnalysis.Scripting.CompilationErrorException' in Microsoft.CodeAnalysis.Scripting.dll Microsoft.CodeAnalysis.Scripting.CompilationErrorException: error CS0246: The type or namespace name 'MyAssembly' could not be found (are you missing a using directive or an assembly reference?)

I added the assembly in the host project too. I've also tried the examples from here but they didn't work either.

What is the correct syntax to add an assembly?

Answer 1

The following snippet does the trick:

var path = Assembly.GetAssembly(typeof(MyAssembly.SomeClass)).Location;
var asm = AssemblyMetadata.CreateFromFile(path).GetReference();

var options = ScriptOptions.Default.AddReferences(asm);

This following works too and it uses Linq to get the loaded assembly:

var asm = AppDomain.CurrentDomain.GetAssemblies()
    .SingleOrDefault(assembly => assembly.GetName().Name == "MyAssembly");

This however gets the loaded assemblies. If the assembly you need is not already loaded, get them using Assembly.GetExecutingAssembly().GetReferencedAssemblies().