Typescript error with async factories

[Ackos95]

I've been trying to create async app initialization using awilix. As container doesn't support async factories I've used pattern recommended here, but typescript trows an error if I try to destruct dependencies in factory function declaration.

Example:

const createContainer = async (): AwilixContainer => {
  const container: AwilixContainer = createContainer();

  const config: TConfigOptions = { dbOptions: { /* ... */ } };
  container.register('config', asValue(config));

  // passing cradle to ensure dependencies inside factory
  const db = await asyncDbFactory(container.cradle);
  container.register('db', asValue(db));
  // rest of the code
}

// db factory
// For this destruction I receive error for type missmatch
// `{ [key: string]: any }` doesn't match `{ config: TConfigOptions }`
const asyncDbFactory = ({ config }: { config: TConfigOptions }) =>
  new Promise((resolve: (db: TDb) => void) => {
    // connection logic

    // resolve(db);
  })

It does work properly if I don't define types in asyncDbFactory

// this way typescript won't mind
const asyncDbFactory(opts: any) => /* ... */

Is there a way to bypass this that I'm not seeing or is it just a price we must pay?

[Ackos95]

If I may suggest simple solution. It can be done by modifying type of container.cradle into any, I know that sounds counter-intuitive but it would enable to manually define type of dependencies and to cast cradle into it when invoking. In previous example it would look something like this:

const createContainer = async (): AwilixContainer => {
  const container: AwilixContainer = createContainer();

  const config: TConfigOptions = { dbOptions: { /* ... */ } };
  container.register('config', asValue(config));

  // passing cradle to ensure dependencies inside factory
  const db = await asyncDbFactory(container.cradle as { config: TConfigOptions });
  container.register('db', asValue(db));
  // rest of the code
}

// db factory
// No error anymore
const asyncDbFactory = ({ config }: { config: TConfigOptions }) =>
  new Promise((resolve: (db: TDb) => void) => {
    // connection logic

    // resolve(db);
  })

I'm aware that this is not a perfect solution, but current cradle type doesn't give much information, and yet it blocks any casting.

[jeffijoe]

I'm fine with that. 😄

As a tip, you can actually use a double cast to get around this:

container.cradle as any as { config: TConfigOptions }

I'll merge your PR and release.

[jeffijoe]

Released as v3.0.6, thanks!