Default Import Error with ioredis Prevents TypeScript Compilation with esModuleInterop Disabled

[bobdercole]

Hello,

My TypeScript projects fails to compile due to an error in some BullMQ files. Here is the error:

$ tsc -p .
node_modules/bullmq/dist/classes/redis-connection.d.ts:3:8 - error TS1259: Module '"/application/node_modules/@types/ioredis/index"' can only be default-imported using the 'esModuleInterop' flag

3 import IORedis, { Redis } from 'ioredis';
         ~~~~~~~

  node_modules/@types/ioredis/index.d.ts:43:1
    43 export = IORedis;
       ~~~~~~~~~~~~~~~~~
    This module is declared with using 'export =', and can only be used with a default import when using the 'esModuleInterop' flag.

I found this problem in the following files:

bullmq/src/classes/redis-connection.ts

Line 2 in 36726bf

import IORedis, { Redis } from 'ioredis';

bullmq/src/commands/index.ts

Line 15 in 36726bf

import IORedis from 'ioredis';

bullmq/src/interfaces/queue-options.ts

Line 3 in 36726bf

import IORedis from 'ioredis';

bullmq/src/interfaces/redis-options.ts

Line 1 in 36726bf

import IORedis from 'ioredis';

bullmq/src/utils.ts

Line 1 in 36726bf

import IORedis from 'ioredis';

bullmq/src/test/test_queue.ts

Line 5 in 36726bf

import IORedis from 'ioredis';

I do have esModuleInterop disabled. The issues seems to go away if I enabled esModuleInterop. However, I don't think that this flag should be required.

I can confirm that the error goes away if the ioredis imports within BullMQ are changed to the recommended ioredis usage:

import * as Redis from "ioredis";
https://github.com/DefinitelyTyped/DefinitelyTyped/blob/946a98e60e6ae4f4f2910f1c75b8403e0f676876/types/ioredis/index.d.ts#L21

Any thoughts? Thanks!

[manast]

That error goes away but don't you get other errors instead? I don't think IORedis typings are fully following the modern TS standard for exporting classes so I am not sure what can be done other than enabling the esModuleInterop flag...

[bobdercole]

I created a PR as a proof of concept. Yes, I did encounter some other errors when I disabled esModuleInterop in BullMQ. I addressed those in the PR as well.

It seems people have had this issue before with ioredis (redis/ioredis#712) and TypeScript in general (microsoft/TypeScript#28009).

I am not sure if my change is conventional. It does fix my problem though. Do you have any thoughts?

[robcresswell]

@bobdercole I have the same issue here, and your patch is correct, aside from the comments from @manast about using the type only, when appropriate. import * as IORedis is the way to go.

[manast]

🎉 This issue has been resolved in version 1.8.1 🎉

The release is available on:

• npm package (@latest dist-tag)
• GitHub release

Your semantic-release bot 📦🚀