如何在错误消息中使用邮递员返回键/值进行AJV验证

Question

Background

I'm using ajv with postman for json schema validation. It works well, however it only gives me a single fail/pass result for an entire schema validation, rather than the exact failing key/value pair:

var Ajv = require('ajv'),
    ajv = new Ajv({logger: console}),
    schema = {
        "properties": {
                "data" : {
                     "type": "object",
                     "properties" : {
                            "categories" : {
                                   "type": "array",
                                   "items" : [
                                           {"type": "object",
                                            "properties" : {
                                                    "id": {"type": "number"},
                                                    "ref": {"type": ['null', 'string']},
                                                    "parent_id": {"type": ['null', 'number']},
                                                    "image": {"type": ['null', 'string']},
         ...

  pm.test('Schema is valid', function() {
    var data = pm.response.json()['data'];
    pm.expect(ajv.validate(schema, {data: data})).to.be.true;

});

Question

How can I make avj/postman return the exact wrong key/pair validation?

update

For this to work, the avj object must be declared like so:

var Ajv = require('ajv'),
ajv = new Ajv({logger: console,
            allErrors: true,
            verbose: true
}),

Answer 1

There is the ajv.errors object, that holds the information.

https://github.com/epoberezkin/ajv#validation-errors

For example, by adding something like this to the pm.expect() statement, it should show the message part of the error in the Postman Tests Results:

pm.expect(ajv.validate(ajv.validate(schema, {data: data}), JSON.stringify(ajv.errors[0].message)).to.be.true;

That's only going to show the first object in the array so you'd need to capture this in a different way if you wanted to iterate through that data.

Answer 2

The correct way to print in the console the error message is by adding a an extra parameter to validate(). First declare a "printErrors" function at the beginning of your Postman script tests:

function printErrors(ajv){
    if(ajv.errors !== null){
        console.log(JSON.stringify(ajv.errors[0]));    
    }
}

Then add the a call to validate, like this:

var ajv = new Ajv({logger: console,
        allErrors: true,
        verbose: true
}),
yourData = {"your Data"}
yourSchema = {"your schema"};
pm.test('Schema is valid', function() {
    pm.expect(ajv.validate(schema, yourData), printErrors(ajv)).to.be.true;
});

You will see the log in the console box. To open it you have to click on the console button, the third one starting from the left.