fix: Add generic to plugin schema definition

[emiljanitzek]

Summary

Update the typescript definition for plugin() on Schema to add generic support. Currently, the plugin() complains when trying to add a plugin with custom Document/Model definitions.

Examples

const myDocumentSchema = new Schema<MyDocument, MyModel>({ name: String });

export default function myPlugin(mySchema: Schema<MyDocument, MyModel>): void {
    mySchema.add({
        plugin: Boolean
    })
}

myDocumentSchema.plugin(myPlugin); // <-- this does not work since Schema in plugin does not support generics

[vkarpov15]

Why are the generics necessary? Adding schema: Schema<DocType, Model<DocType>, SchemaDefinitionType> should be sufficient for this case, shouldn't it?

[emiljanitzek]

That's correct, it would be sufficient for the case above. I was following the same pattern as found with post/pre methods just below. I can update according to your suggestion if you would prefer that?

[vkarpov15]

Yes please, I'd rather avoid adding unnecessary generic params if possible.

[vkarpov15]

Thanks 👍