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'use strict';const assert = require('assert');const mongoose = require('../../');const start = require('../common');
describe('schemaTypes', function() {  let db;  const Schema = mongoose.Schema;
  before(function() {    db = mongoose.createConnection(start.uri);  });
  after(async function() {    await db.close();  });
  /**   * _New in Mongoose 4.4.0:_ Mongoose supports custom types. Before you   * reach for a custom type, however, know that a custom type is overkill   * for most use cases. You can do most basic tasks with   * [custom getters/setters](http://mongoosejs.com/docs/2.7.x/docs/getters-setters.html),   * [virtuals](http://mongoosejs.com/docs/guide.html#virtuals), and   * [single embedded docs](http://mongoosejs.com/docs/subdocs.html#single-embedded).   *   * Let's take a look at an example of a basic schema type: a 1-byte integer.   * To create a new schema type, you need to inherit from `mongoose.SchemaType`   * and add the corresponding property to `mongoose.Schema.Types`. The one   * method you need to implement is the `cast()` method.   */  it('Creating a Basic Custom Schema Type', function() {    class Int8 extends mongoose.SchemaType {      constructor(key, options) {        super(key, options, 'Int8');      }
      // `cast()` takes a parameter that can be anything. You need to      // validate the provided `val` and throw a `CastError` if you      // can't convert it.      cast(val) {        let _val = Number(val);        if (isNaN(_val)) {          throw new Error('Int8: ' + val + ' is not a number');        }        _val = Math.round(_val);        if (_val < -0x80 || _val > 0x7F) {          throw new Error('Int8: ' + val +            ' is outside of the range of valid 8-bit ints');        }        return _val;      }    }
    // Don't forget to add `Int8` to the type registry    mongoose.Schema.Types.Int8 = Int8;
    const testSchema = new Schema({ test: Int8 });    const Test = mongoose.model('CustomTypeExample', testSchema);
    const t = new Test();    t.test = 'abc';    assert.ok(t.validateSync());    assert.equal(t.validateSync().errors['test'].name, 'CastError');    assert.equal(t.validateSync().errors['test'].message,      'Cast to Int8 failed for value "abc" (type string) at path "test"');    assert.equal(t.validateSync().errors['test'].reason.message,      'Int8: abc is not a number');  });});