Mongoose and array of ref UUID's does not convert

问题

When using the library mongoose-uuid, I am able to setup UUID types for my schemas, so when I read the data it is in string (utf-8) format and when I save the data it is in UUID ObjectID BSON type 4 format. This works great with top level or flat direct values and ref definitions in my schema. However, when I have a UUID's in an array of ref's in a schema, the array saves to the database correctly, However when it is presented it is in its raw type. Based on the example below you can see scope_id is presented in the right format but the entitlements are not.

Here are the versions I am using: mongoose-uuid - 2.3.0 mongoose - 5.5.11

I have tried modifying the library (mongoose-uuid) by changing the getter and converting the value, however, when I do so, it works when presenting but fails when it saves to the database. This is most likely due to the fact that the value is converted or casted before saving to the database.

Here is an example schema

    {
      "code": {
        "type": String,
        "required": true
      }, 
      "scope_id": {
        "type": mongoose.Types.UUID,
        "ref": "scopes"
      },
      "entitlements": [{
        "type": mongoose.Types.UUID,
        "ref": "entitlements"
      }]
    }

Example actual response

{
    "entitlements": [
        "zMihi1BKRomM1Q41p7hgLA==",
        "ztOYL7n1RoGA6aoc0TcqoQ=="
    ],
    "code": "APPUSR",
    "scope_id": "b8f80c82-8325-4ffd-bfd7-e373a90e7c45",
    "id": "32e79061-e531-45ad-b934-56811e2ad713"
}

Expected Response

{
    "entitlements": [
        "ccc8a18b-504a-4689-8cd5-0e35a7b8602c",
        "ced3982f-b9f5-4681-80e9-aa1cd1372aa1"
    ],
    "code": "APPUSR",
    "scope_id": "b8f80c82-8325-4ffd-bfd7-e373a90e7c45",
    "id": "32e79061-e531-45ad-b934-56811e2ad713"
}

回答1:

As per my observation, if you change the below function in mongoose, it works fine

SchemaUUID.prototype.cast = function (value, doc, init) {
  console.log("cast", value, doc, init)

  if (value instanceof mongoose.Types.Buffer.Binary) {
    if (init) {
      return getter(value);
    } else {
      return value;
    }
  }

  if (typeof value === 'string') {
    var uuidBuffer = new mongoose.Types.Buffer(uuidParse.parse(value));

    uuidBuffer.subtype(bson.Binary.SUBTYPE_UUID);

    return uuidBuffer.toObject();
  }

  throw new Error('Could not cast ' + value + ' to UUID.');
};

Basically when you save objects init is false and when its initiated init is true

回答2:

As mentioned above, the code does work but breaks another part of the code. I found a solution that corrects this:

It is a slight amendment to the code above

SchemaUUID.prototype.cast = function (value, doc, init) {

console.log("cast", value, doc, init)

  if (value instanceof mongoose.Types.Buffer.Binary) {
    if (init && doc instanceof mongoose.Types.Embedded) {
      return getter(value);
    }
    return value;
  }

  if (typeof value === 'string') {
    var uuidBuffer = new mongoose.Types.Buffer(uuidParse.parse(value));

    uuidBuffer.subtype(bson.Binary.SUBTYPE_UUID);

    return uuidBuffer.toObject();
  }

  throw new Error('Could not cast ' + value + ' to UUID.');
};

This alternate version of the code allows for updates such as POST and PATCH to be applied.

来源：https://stackoverflow.com/questions/56494736/mongoose-and-array-of-ref-uuids-does-not-convert

标签

express

mongoose

uuid

mongoose-schema