(node:1124) DeprecationWarning: collection.ensureIndex is deprecated. Use createIndexes instead.

[lucio-oliveira]

I solved this Issue in my application using this value in my mongoose connection:

mongoose.connect('mongodb+srv://lucio:@cluster0-6izqv.mongodb.net/test?retryWrites=true&w=majority',{
useCreateIndex:true,
} );

[AbdelrahmanHafez]

Duplicate of #6880
TL;DR: Just add useCreateIndex: true the way you currently are doing in order to avoid the deprecation warning.

[vkarpov15]

https://mongoosejs.com/docs/deprecations.html