How do you remove a model from mongoose?

try this

delete mongoose.connection.models['Book'];

and then re-register/re-initialize it . it will work fine

It appears that you'd have to overwrite some of the source code in order to be able to remove a model an add a new one since Mongoose makes sure that a model doesn't exist before it's willing to create a new one, which may or may not be more than you care to do:

if (this.models[name] && !collection) {    // model exists but we are not subclassing with custom collection    if (schema instanceof Schema && schema != this.models[name].schema) {      throw new MongooseError.OverwriteModelError(name);    }    return this.models[name];}

Line 587 https://github.com/LearnBoost/mongoose/blob/master/lib/connection.js

Question Author's Update:

Thanks to this answer I discovered that you can access the models defined on the connection through connection.models. In my scenario I was testing a mongoose plugin with Mocha and and I wanted to clear the models between each unit test.

afterEach(function () {    mongoose.connection.models = {};});

This is actually a better way to get rid of models, schemas and collections in mongoose

mongoose.connections.forEach(connection => {  const modelNames = Object.keys(connection.models)  modelNames.forEach(modelName => {    delete connection.models[modelName]  })  const collectionNames = Object.keys(connection.collections)  collectionNames.forEach(collectionName => {    delete connection.collections[collectionName]  })})const modelSchemaNames = Object.keys(mongoose.modelSchemas)modelSchemaNames.forEach(modelSchemaName => {  delete mongoose.modelSchemas[modelSchemaName]})

Reference: https://github.com/Automattic/mongoose/issues/2874#issuecomment-388588452