.populate() returns findOne() on empty string. This results in a random find.

[PVermeer]

First thanks for this great repo!

Case

Bug

Issue

Populate on a ref field that has an empty string returns a random document from that collection.

Possible solution

Looking at the source, the populate() is the return of a findOne(). findOne() will return the first value when no arguments are supplied. I would suggest to check for falsy on the value of the path argument of the populate function and to return null if false.

Info

• Environment: Angular 8
• Adapter: IndexedDB
• Stack:

Code

Example:

transaction.populate('account').then(x => console.log(x.name));

// Schema to populate
{
title: 'sdfsdgsg',
  version: 0,
  description: 'cvbcvbvb',
  type: 'object',

  properties: {
    account: {
      ref: 'accounts',
      type: 'string',
    },
 }

// Schema account
{
title: 'fghfgh',
  version: 0,
  description: 'tryrtytry',
  type: 'object',

  properties: {
    name: {
      type: 'string'      
    }    
  }
}
 

Suggested fix:

populate(path) {


        const schemaObj = this.collection.schema.getSchemaByObjectPath(path);
        const value = this.get(path);

// fix or something like this
if (!value) { return Promise.resolve(null); }
//---      

        if (!schemaObj) {
            throw newRxError('DOC5', {
                path
            });
        }
        if (!schemaObj.ref) {
            throw newRxError('DOC6', {
                path,
                schemaObj
            });
        }

        const refCollection = this.collection.database.collections[schemaObj.ref];
        if (!refCollection) {
            throw newRxError('DOC7', {
                ref: schemaObj.ref,
                path,
                schemaObj
            });
        }

        if (schemaObj.type === 'array')
            return Promise.all(value.map(id => refCollection.findOne(id).exec()));
        else
            return refCollection.findOne(value).exec();
    },

[pubkey]

@PVermeer thanks for investigation.
The proposed fix looks good for me. Do you have the time to create a PR with unit-test and the fix?

[PVermeer]

I'll try to look into it this week.