Array Types & Fields

Array types & Fields

It is much easier to declare the array field's type as type[] instead of Array<type>.

But in some cases, Typescript could give you a warning, when you would like to use any mongoose array methods on the array field. To avoid such behavior, you could always declare the array field via mongoose.Types.Array<type> or mongoose.Schema.Types.Array<type>

Example:

class ModelClass {
  // required field, with empty array by default.
  @prop({ type: String, required: true, default: [] })
  public field!: mongoose.Types.Array<string>;
}

Why is the long type needed?

Mainly, because mongoose documents and their arrays fields have their pre-build methods, which slightly differ from Array.method.prototype. But at runtime, these methods already exist (because an array is always an mongoose array). So, using type[] is just more convenient way to write a shorter type instead of the mongoose.Types if the functions are not used.

For more information you could look at GitHub issue #509.

Why is the type option always required?

Because Reflection currently does not give out detailed information, it only "dumbs down" the type to Array, see typescript issue #300 for more.