Unreported breaking change - insertMany with lean option

[nadavhalfon]

Prerequisites

• I have written a descriptive issue title
• I have searched existing issues to ensure the issue has not already been raised

Issue

When this issue was raised: #14372
The fix was to skip hydration in "insertMany" - this causes a bug where insertMany suddenly does't take care for "defaults"
I think it should be mention somewhere, just wanted to point it out 🙏

Thank you very much for your work !

[vkarpov15]

That's a good point, we will add this to our docs. As a workaround, you can use Model.applyDefaults() to apply the defaults to your lean objects before saving as follows.

await MyModel.insertMany(docs.map(doc => MyModel.applyDefaults(doc)), { lean: true })

[7freaks-otte]

Note: This seems to have appeared in the 7.x branch as well - presumably with 7.6.10

[ayoubkhial]

This behavior is still present in version 8.7.0. It's not just the default values but also timestamps.