Mongo 3.6 debug validation using jsonSchema

Question

I'm following a course from mongodb university to learn new features in the release 3.6, and I'm unable to resolve why my validator is invalid.

This is how I created the collection:

db.getSiblingDB("TSA").createCollection("claims", {
    validator: {
        $jsonSchema: {
            bsonType: "object",
            properties: {
                _id: { },
                airportCode: { type: "string", minLength: 3 },
                airportName: { type: "string" },
                airlineName: { type: "string", minLength: 5 },
                claims: {
                    bsonType: "object",
                    properties: {
                        itemCategory: { bsonType: "array", maxItems: 3 },
                        amount: { type: "string", pattern: "^\$.*" }
                    }
                }
            },
            required: ["airportCode", "airlineName", "claims"],
            additionalProperties: false
        }
    }
})

Then, I try to insert this object:

db.getSiblingDB("TSA").claims.insertOne({
    "airportCode": "ABE",
    "airportName": "Lehigh Valley International Airport, Allentown",
    "airlineName": "MongoAir",
    "claims": {
        "claimType": "Property Damage",
        "claimSite": "Checked Baggage",
        "itemCategory": [ "Sporting Equipment & Supplies" ],
        "amount": "$180.00"
    }
})

Getting the following error:

WriteError({
    "index" : 0,
    "code" : 121,
    "errmsg" : "Document failed validation",
    "op" : {
        "_id" : ObjectId("5a705318d3d6c18337f07282"),
        "airportCode" : "ABE",
        "airportName" : "Lehigh Valley International Airport, Allentown",
        "airlineName" : "MongoAir",
        "claims" : {
            "claimType" : "Property Damage",
            "claimSite" : "Checked Baggage",
            "itemCategory" : [
                    "Sporting Equipment & Supplies"
            ],
            "amount" : "$180.00"
        }
    }
})

My question is, is there some way to debug the validator like "property X must be Y type" instead of getting a generic "Document failed validation"?

Answer 1

As of MongoDB 3.6, there is no feedback mechanism that would inform what part of a document failed validation during a server-side check. A corresponding feature request is open: SERVER-20547: Expose the reason an operation fails document validation . For now, it is left to the application code to perform its own validation if detailed feedback is required.

Answer 2

If you use regex pattern string, backslash itself must be escaped too:

db.getSiblingDB("TSA").createCollection("claims", {
    validator: {
        $jsonSchema: {
            bsonType: "object",
            properties: {
                _id: { },
                airportCode: { type: "string", minLength: 3 },
                airportName: { type: "string" },
                airlineName: { type: "string", minLength: 5 },
                claims: {
                    bsonType: "object",
                    properties: {
                        itemCategory: { bsonType: "array", maxItems: 3 },
                        amount: { type: "string", pattern: "^\\$.*" }
                    }
                }
            },
            required: ["airportCode", "airlineName", "claims"],
            additionalProperties: false
        }
    }
})