Configuring Custom Validators for Individual Paths in Archetype

archetype-20171110-validate-config.js

const Archetype = require('archetype');
const assert = require('assert');

// The 2nd param to the `$validate` function is the schema path,
// so `{ $type: 'number', ... }`. Can use that to configure
// validators from your schema path, like writing your own
// min/max validator
const minMax = (v, path) => {
  const { $min, $max } = path;
  assert.ok($min == null || v >= $min, `${v} < ${$min}`);
  assert.ok($max == null || v <= $max, `${v} > ${$max}`);
};

const TweetType = new Archetype({
  length: {
    $type: 'number',
    // minMax gets access to `$min` and `$max` below
    $validate: minMax,
    $min: 0,
    $max: 140
  },
  retweets: {
    $type: 'number',
    // minMax behaves differently because different `$min` and `$max`
    $validate: minMax,
    $min: 100
  }
}).compile('TweetType');

// OK
new TweetType({ length: 127, retweets: 100 });

try {
  new TweetType({ length: 151 });
} catch (error) {
  // Error: length: 151 > 140
  console.error(error.message);
}

try {
  new TweetType({ retweets: 99 });
} catch (error) {
  // Error: retweets: 99 < 100
  console.error(error.message);
}