Types missing for custom resolver

[kimroen]

As documented here and added to this library here, when creating a driver you can pass in a custom resolver:

import neo4j from 'neo4j-driver';

const driver = neo4j.driver(
  'my-uri',
  neo4j.auth.basic('username', 'password'),
  {
    resolver: address => ['my', 'array', 'of', 'addresses'],
  },
);

With the current types, this doesn't work. You are told that resolver isn't a known property on Config.

This seems fair enough, because we can see that this is the case in the type definition here:

neo4j-javascript-driver/types/v1/driver.d.ts

Lines 50 to 66 in c8d2ad9

	declare interface Config {
	encrypted?: boolean | EncryptionLevel
	trust?: TrustStrategy
	trustedCertificates?: string[]
	knownHosts?: string
	/**
	* @deprecated use {@link maxConnectionPoolSize} instead.
	*/
	connectionPoolSize?: number
	maxConnectionPoolSize?: number
	maxTransactionRetryTime?: number
	loadBalancingStrategy?: LoadBalancingStrategy
	maxConnectionLifetime?: number
	connectionTimeout?: number
	disableLosslessIntegers?: boolean
	logging?: LoggingConfig
	}

This resolver function isn't used immediately anywhere, it happens quite far away from the constructor. I'm guessing that the resolver referenced here is the one we're looking for:

neo4j-javascript-driver/src/internal/resolver/configured-custom-resolver.js

Lines 30 to 41 in d876a45

	resolve (seedRouter) {
	return new Promise(resolve =>
	resolve(this._resolverFunction(seedRouter.asHostPort()))
	).then(resolved => {
	if (!Array.isArray(resolved)) {
	throw new TypeError(
	`Configured resolver function should either return an array of addresses or a Promise resolved with an array of addresses.` +
	`Each address is '<host>:<port>'. Got: ${resolved}`
	)
	}
	return resolved.map(r => ServerAddress.fromUrl(r))
	})

If so, the definition should be something like this, allowing either an array of strings or a promise resolving to an array of strings:

declare interface Config {
  ...
  resolver?: (address: string) => Promise<string[]> | string[]
}

Hope that's useful!

[zhenlineo]

Thanks very much for reporting this. We will plan a release to includes the fixes soon.