Patch data resolver for Feathers Schema

[RuneSP]

Hi,

I'm tempted to switch from mongoose models to use feathers schemas instead, as its much easier to share interfaces, validation etc with frontend.

I'm currently stuck on how to correctly create a patch resolver, the examples only mentions an "userPatchResolver".

If we take the UserSchema from the examples page. If I use the userDataResolver for a patch event and only updates the user email, it will throw an error with password missing, as it should.

I guess I could make a userPatchSchema, that extends userSchema and remove password from required properties, but this will still throw an error if not all other required properties are in the patch data.

I think the patch resolver should only resolve / validate the properties that are present in the patch data, but I'm not really sure if thats possible?

Thanks

[daffl]

The new CLI uses extension setting the required property to an empty array which means fields that do not exist don't get validated:

import { schema } from '@feathersjs/schema';

export const userDataSchema = schema({
  $id: 'UserData',
  type: 'object',
  additionalProperties: false,
  required: ['email', 'password'],
  properties: {
    id: { type: 'number' },
    email: { type: 'string' },
    password: { type: 'string' }
  }
});

export const userPatchSchema = schema({
  $id: 'UserPatch',
  type: 'object',
  additionalProperties: false,
  required: [],
  properties: {
    ...userDataSchema.properties
  }
});

[RuneSP]

That works, but will still accept null values (and convert them to empty string, for strings). I guess I can set minLength to prevent this for strings.

Another question, feathers / json schema doesnt seem to handle uniqueness of properties. I can achieve this with hooks, but would rather have it set at database level. What would be the feathery way to achieve this using schemas?

[daffl]

Interesting, I didn't know it did that with null values. I wonder if there is an AJV setting to prevent that.

Uniqueness should be handled on the database level whenever possible but can also be done in Feathers with a hook that makes a find call for the field that should be unique and checks the total:

import { Conflict } from '@feathersjs/errors'

app.service('myservice').hooks({
  before: {
    create: [async context => {
      const { name } = context.data

      const { total } = await context.service.find({
        query: {
          // This means it will just do a quick count to return the total
          $limit: 0,
          name
        }
      })

      if (total > 0) {
        throw new Conflict(`Entry with ${name} already exists`)
      }
    }]
  }
})