mongoose-beautiful-unique-validation

Plug-in for Mongoose that turns duplicate errors into regular Mongoose validation errors.

Mongoose's unique constraint actually relies on MongoDB's unique indexes. It means that, if you have a schema like that one:

mongoose.Schema({
    name: {
        type: String,
        unique: true
    }
});

Unique constraint failures will be reported with this kind of error:

{
    "name": "MongoError",
    "message": "insertDocument :: caused by :: 11000 E11000 duplicate key error index: example.users.$name_1 dup key: { : \"John\" }",
    "index": 0,
    "code": 11000,
    "errmsg": "insertDocument :: caused by :: 11000 E11000 duplicate key error index: example.users.$name_1 dup key: { : \"John\" }"
}

This is not the same kind of error as normal Validation errors: it will introduce more checks in your code if you want to handle them. This plug-in solves this problem by converting uniqueness errors (E11000 and E11001) into regular Validation errors.

{
    "name": "ValidationError",
    "message": "Model validation failed",
    "errors": {
        "name": {
            "name":"ValidatorError",
            "properties": {
                "type": "Duplicate value",
                "message": "Custom error message",
                "path": "name",
                "value": "John"
            },
            "message": "Custom error message",
            "kind": "Duplicate value",
            "path": "name",
            "value": "John"
        }
    }
}

Install

npm install --save mongoose-beautiful-unique-validation

Example

let beautifyUnique = require('mongoose-beautiful-unique-validation');
let userSchema = mongoose.Schema({
    name: {
        type: String,
        // this will be the uniqueness error message
        // leave it to "true" to keep the default one:
        unique: 'Two users cannot share the same username'
    }
});

// enables beautifying
userSchema.plugin(beautifyUnique);

// let's create two conflicting documents
let User = mongoose.model('Model', userSchema);
let admin1 = new User({
    name: 'admin'
});

let admin2 = new User({
    name: 'admin'
});

admin1.save()
    .then(() => console.log('Success saving admin1!'))
    .catch(err => console.error('admin1 could not be saved: ', err));

admin2.save()
    .then(() => console.log('Success saving admin2!'))
    .catch(err => console.error('admin2 could not be saved: ', err));

// will print:
// Success saving admin1!
// admin2 could not be saved: [ValidationError: User validation failed]

Usage

Schemata that will produce beautified errors need to be plugged in with this module using the .plugin() method.

You need to plug in this module after declaring all indexes on the schema, otherwise they will not be beautified.

By default, the ValidatorError message will be Validator failed for path xxx with value xxx. If you want to override it, add your custom message in the unique field (instead of true), during the schema's creation.

This plug-in overrides the .save() method to add beautifying behavior. If you do not want it, you can pass the beautifyUnique option to false:

document.save({
    beautifyUnique: false
}).then(() => {
    // stuff
});

Contributing

Check out the contribution guide.

License

See the LICENSE.