`mongoose.set('autoIndex', false)` having no effect

[kiprobinson]

Do you want to request a feature or report a bug? I'm not sure. The documentation in one place says this should work. In another place, it does not mention it. If this is supposed to work, then I'd call this a bug. If it is not, then please update the documentation (or, ideally, implement this feature).

What is the current behavior?
mongoose.set('autoIndex', false); has no effect.

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

const mongoose = require('mongoose');
mongoose.set('autoIndex', false);

const testSchema = new mongoose.Schema({
    field1: {type: String, index: true},
    field2: {type: String, index: false},
    field3: {type: String, unique: true},
});
const testModel = mongoose.model('Test', testSchema);

mongoose.connect(`mongodb://localhost:27017/testdb`).then(() =>
    console.log(`Successfully connected to MongoDB server`)
).catch((err) => {
    console.error(err);
});

What is the expected behavior?

• If the tests collection does not already exist, it should not be created automatically.
  • Actual: The tests collection is created automatically.
• If the tests collection does already exist, no new indexes should be added automatically.
  • Actual: The indexes are added to tests collection automatically.

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

• Node: 10.16.0
• Mongoose: 5.7.0
• MongoDB Server: 4.2.0 Community
• MongoDB NPM package: 3.3.2

Additional Information
According to the documentation for autoIndex:

The autoIndex option is set to true by default. You can change this default by setting mongoose.set('autoIndex', false);

However, the documentation for mongoose.set() doesn't mention autoIndex as a supported setting

Also, in the "Indexes" section of the guide, it lists four ways of setting the property, but none are mongoose.set().