Type LeanDocument seems not working for Array of Array

[lutherman]

Hi,

The type LeanDocument seems not working for Array of Array.

I have some source codes like that:

const SheetSchema = new Schema<Sheet, SheetModel> ({
  name: {
    type: String,
    required: true,
  },
  projectId: { type: Schema.Types.ObjectId },
  folderId: { type: Schema.Types.ObjectId },
  search: [new SheetSavedSearchSchema()],
});

const SheetSavedSearchSchema = new Schema ({
  searchName: String,
  searchCriteria: [[new SearchCriteriaSchema()]], // <-- Array of Array !!!
});

And I get its LeanDocument by function toObject:

const sheet: Sheet = sheetDoc.toObject();

However, the type error occurs:

Type 'LeanDocument<Sheet & Document<any, any>>' is not assignable to type 'Sheet'.
  Types of property 'search' are incompatible.
    Type 'LeanDocument<SheetSavedSearch>[]' is not assignable to type 'SheetSavedSearch[]'.
      Type 'LeanDocument<SheetSavedSearch>' is not assignable to type 'SheetSavedSearch'.
        Types of property 'searchCriteria' are incompatible.
          Type 'LeanDocument<SearchCriteria[]>[]' is not assignable to type 'SearchCriteria[][]'.
            Type 'LeanDocument<SearchCriteria[]>' is missing the following properties from type 'SearchCriteria[]': [Symbol.iterator], [Symbol.unscopables]ts(2322)

Did i do something wrong on schema declaration?

---

nodejs: 12.19.0
mongodb: 4.2.7
mongoose: 5.12.11

[IslandRhythms]

before I attempt to repro this, try swapping the position of your two schemas. SheetSavedSearchSchema is used before it is declared so that could be causing your problem. Also, if the problem still persists please include other things not defined like the search criteria schema

[lutherman]

I wrote a test code to simplify the situation.

Test code:

import { Model, Schema } from 'mongoose';

interface ITest {
  name: string;
  arrayOfArray: string[][]; // <-- Array of Array
}

const testSchema = new Schema<ITest, Model<ITest>>({
  name: {
    type: String,
    required: true,
  },
  arrayOfArray: [[String]],
});

testSchema.methods.getArrayOfArray = function (): string[][] { // <-- function to return Array of Array
  const test = this.toObject();

  return test.arrayOfArray; // <-- error here
};

And its error message:

Type 'LeanDocument<string[]>[]' is not assignable to type 'string[][]'.
  Type 'LeanDocument<string[]>' is missing the following properties from type 'string[]': [Symbol.iterator], [Symbol.unscopables]ts(2322)

If the field is single array, will be OK.