ajv: Overriding default errors on custom keyword is not working

I am using version 4.0.5 <- there I defined the following keyword:

ajv.addKeyword("validateMaxPoints", {
  errors: true,
  async: false,
  validate: function(value, dataObject) {
    if (this.errors === null)
      this.errors = [];

    this.errors.push({
      keyword: "validateMaxPoints",
      message: "maxPoints attribute should be " + 0 + ", but is " + 0,
      params: {
        keyword: "validateMaxPoints"
      }
    });

    return false;
  }
});

I added validateMaxPoints to the schema, compiled it and validated my data.

I expected to see my custom error object in the errors array, but instead I got:

{ keyword: "validateMaxPoints",
    dataPath: "",
    schemaPath: "#/validateMaxPoints",
    params: { keyword: "validateMaxPoints" },
    message: "should pass "validateMaxPoints" keyword validation",
    schema: true,
    parentSchema: 
     { type: "object",
       properties: [Object],
       required: [Object],
       validateMaxPoints: true },
    data: 
     { user: "112233445566778899101112",
       title: "title",
       timestamp: "Wed May 04 2016 12:26:24 GMT+0200 (CEST)",
       maxPoints: 10,
       type: "list",
       limit: "",
       questions: [Object] } }

Is this an error or did I missed something?

About this issue

Original URL
State: closed
Created 8 years ago
Reactions: 2
Comments: 19 (8 by maintainers)

Most upvoted comments

This is a pretty awkward API…

+34

QuotableWater7 on Aug 7, 2018

I didn’t grok what it might mean to add errors to the validator function until I saw @epoberezkin’s example of doing so. Sure would have helped to see this in the documentation:

ajv.addKeyword("validateMaxPoints", {
  errors: true,
  validate: function xyz(value, dataObject) {
    xyz.errors = [];

    xyz.errors.push({
      keyword: "validateMaxPoints",
      message: "maxPoints attribute should be " + 0 + ", but is " + 0,
      params: {
        keyword: "validateMaxPoints"
      }
    });

    return false;
  }
});

+13

jtlapp on Sep 22, 2017

ajv.addKeyword("validateMaxPoints", {
  errors: true,
  validate: function xyz(value, dataObject) {
    xyz.errors = [];

    xyz.errors.push({
      keyword: "validateMaxPoints",
      message: "maxPoints attribute should be " + 0 + ", but is " + 0,
      params: {
        keyword: "validateMaxPoints"
      }
    });

    return false;
  }
});

epoberezkin on May 9, 2016

Almost lost my mind trying to figure out why the errors I was assigning to this.errors were not showing up. It might be helpful to include a specific note on the need to name your validate function in order for this setup to work? The docs at this point are not clear enough on that point.

thomaux on Jun 13, 2019

https://tonicdev.com/esp/5731a55eabbf001200bbc028 - it works. The issue seems to be though that it doesn’t validate this custom keyword if there is some other error before it.

epoberezkin on May 10, 2016