New Code Action: add service/dependency to class

[ravero]

When working on a project with DI, constructor injection is the most common way of adding a dependency (which will be resolved later by the DI framework).

I've thought that it could be a code action. A suggested workflow:

1. The code action can be available anywhere inside a code class
2. When invoking Add service or dependency to class a modal should be shown with a text field to search for a class or interface (with autocomplete as you type) and another to name the field.
3. After selecting the type and setting the name, the code action would add:

• A read-only field with the type of the dependency
• A constructor argument
• Setting the field to the argument of the constructor

Example:

public class Test
{
    readonly IService service;
    public Test(IService service) { this.service = service }

    // rest of the class implementation
}

Other considerations:

• The field name can be suggested based on the type name, similar to how Visual Studio suggests in Intellisense
• Preserve the order and position of other existing arguments on the constructor

[matthewrdev]

@ravero I can see this being particularly useful for us while developing our app.

A few additional ideas:

• A checkbox to make the injection Lazy or not. I use lazy extensively in all my software to optimise service creation.
• The field name should default to the service name, without the I prefix, with the first letter being in lower case.
• The user can type the type name and MFractor should automatically find its fully qualified type. For example, typeing IMyService will trigger MFractor to search the project domain for any type that matches IMyService and suggest the result (MyApp.Services.IMyService).
• I think the feature should be named Add Class Dependency.

[ravero]

@matthewrdev I agree with all your points.

I would still keep a text field on the dialog for customising the field name. Sometimes I want to simplify interfaces with compound names (like IServicesCollection, a builtin type on the Microsoft DI engine for ASP.NET Core that I frequently simplify to services).

The feature name is short and descriptive, I would go with it.