Use const enums for BindingScope, BindingType, TargetType

[JoshuaKGoldberg]

Now that TypeScript supports string values for enums, it'd be very convenient to switch from this:

type BindingScope = "Singleton" | "Transient" | "Request";
type BindingType = "ConstantValue" | "Constructor" | "DynamicValue" | "Factory" | "Function" | "Instance" | "Invalid" | "Provider";
type TargetType = "ConstructorArgument" | "ClassProperty" | "Variable";    

...to this:

const enum BindingScope {
    Singleton = "Singleton",
    Transient = "Transient",
    Request = "Request",
}

const enum BindingType {
    ConstantValue = "ConstantValue",
    Constructor = "Constructor",
    DynamicValue = "DynamicValue",
    Factory = "Factory",
    Function = "Function",
    Instance = "Instance",
    Invalid = "Invalid",
    Provider = "Provider",
}

const enum TargetType {
    ConstructorArgument = "ConstructorArgument",
    ClassProperty = "ClassProperty",
    Variable = "Variable",
}

That way, instead of hardcoding string literals:

const container = new Container({
    defaultScope: "Singleton",
});

...we can use slightly-easier-to-get-intellisense-for enum members:

const container = new Container({
    defaultScope: BindingScope.Singleton,
});

[remojansen]

This change looks good to me. Are u planning to send a PR?

[JoshuaKGoldberg]

Yes :)

[JoshuaKGoldberg]

You know, this actually is a breaking change. You would no longer be able to use sring literals as many likely do. I'll hold off the change.

microsoft/TypeScript#17690
microsoft/TypeScript#3192 (comment)

Steps to make the change locally are:

• Delete literal_types.ts
• Perform the OP's suggested replacement in interfaces.ts
• Replace usages of the enum types exported from that file with the newly exported enums in interfaces.ts

[JoshuaKGoldberg]

microsoft/TypeScript#17690 (comment)

Will just use a const object.

[remojansen]

@JoshuaKGoldberg I noticed that we already have them https://github.com/inversify/InversifyJS/blob/e3b2871729aeb328ef5d2366282bffa4dc2c1a62/src/constants/literal_types.ts but they are not exposed

[remojansen]

Closing this issue by #718

You can now do:

import { BindingScopeEnum, Container  } from "inversify";

const container = new Container({
    defaultScope: BindingScopeEnum.Singleton,
});

This feature is available in 4.7.0 🎉