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typescriptknex.js

Typescript type for Promise

How best to type the below code without the Promise: any as I currently have it?

export const up = function(knex: knex, Promise: any): Promise<knex> {
  return Promise.all([
    knex.schema.createTable(
      'counters',
      (table: knex.TableBuilder): void => {
        table.increments('id').primary();
        table.integer('count');
      }
    ),
  ]);
};

I have tried PromiseConstructor but then there is an error with Promise<knex> being returned. Can't seem to find any documentation on typing knex.js migrations.

Solution

  • Why should the return type be Promise<knex>?

    knex.schema.createTable returns a SchemaBuilder which extends ChainableInterface, which ultimately extends Bluebird<any>, so the return type is Promise<any[]>.