TS/ESlint: pre hook returning a Promise

[qqilihq]

Do you want to request a feature or report a bug?

Bug?

What is the current behavior?

We just updated to the latest Mongoose version 5.12.8 and got rid of the @types/mongoose. We had a couple of pre save hooks which used an async function. This has worked fine so far (i.e. compiled via TypeScript and verified working at runtime).

If the current behavior is a bug, please provide the steps to reproduce.

Since using Mongoose’s typings, the following code produces an ESLint error:

// PRODUCES ESLINT ERROR:
// Promise returned in function argument where a void return was expected.eslint
// @typescript-eslint/no-misused-promises
mySchema.pre('save', async function () {
   // some async function returning a Promise
});

What is the expected behavior?

I assume that it’s valid behavior to return a Promise (as stated, Mongoose handled this fine in the past). So the typings should include the case of returning a Promise<void> instead of void, so that the linting passes.

What are the versions of Node.js, Mongoose and MongoDB you are using? Note that "latest" is not a version.

• Mongoose 5.12.8
• ESLint with plugin:promise/recommended

[vkarpov15]

Thanks for reporting, we'll look into this and fix over the next couple of days if we can confirm this is a bug.

[qqilihq]

Great, thanks! Let me know if I can help with a reproduction!