Fix schema property type definition in SchemaType

[sderrow]

Summary

Currently, the SchemaType property of schema is required in the type definition and its JSDoc describes the property as "The schema this SchemaType instance is part of".

Instead, based on how mongoose actually works, it should be optional and the JSDoc should be changed, since it's not actually the Schema that the SchemaType is part of. Instead, the schema property only exists when the SchemaType is for a subdocument or document array and it refers to the actual subdocument schema itself.

Examples

Here's an example showing how the schema property isn't present on every SchemaType, just to prove that the Typescript definition should be changed to optional and its JSDoc should be modified accordingly.

import mongoose from "mongoose";

type Person = {
  _id: mongoose.Types.ObjectId;
  name: string;
  doc: {
    _id: mongoose.Types.ObjectId;
    title: string;
  };
};

const personSchema = new mongoose.Schema<Person>(
  {
    name: { type: String, required: true },
    doc: {
      type: {
        title: String,
      },
    },
  },
  { versionKey: false },
);

const Person = mongoose.model("Person", personSchema);

for (const [path, schemaType] of Object.entries(personSchema.paths)) {
  let desc = "";
  if ("schema" in schemaType) {
    desc = Object.keys(schemaType.schema.paths).join(", ");
  } else {
    desc = "n/a";
  }
  console.log(`${path} --> ${desc}`);
  /* OUTPUT:
  name --> n/a
  doc --> title, _id
  _id --> n/a
  */
}

[vkarpov15]

Thanks 👍