How do I test JSON schema in postman using tv4?

Question

This is what i am trying, but it always passes the test even for bad results.

pm.test("Schema is valid", function () {
    var data = pm.response.json();
    var schema = {
        ...
        my schema
        ...
    };
    tv4.validate(data, schema);
});

Answer 1

The reason this doesn't work is (in short) that the underlying library used by Postman (tv4) is no longer maintained. Having come across the problem earlier today, I found a solution :

tv4.validate(data, schema, false, true)

The latter two parameters are checkRecursive and banUnknownProperties . Setting these two flags as shown above make the validation work as expected.

You may also find this code snippet useful, which reports any validation errors via the console:

pm.test("Response body is valid", function() {
  var data = JSON.parse(responseBody);
  var valid = tv4.validate(data, schema, false, true);
  if (valid !== true) {
      console.log(tv4.error);
  }
  pm.expect(valid).to.be.true;
});