Thursday, February 28, 2019

Possible validation bug

I created an issue in github for an possible validation related bug.

I'm trying to get hibernate-validator 6.0.X to work and have run into an issue and am not sure if what I'm seeing in the GWT codebase is a bug or not.

I'm using Validator.validateValue(...) in my tests and have encountered a bug where constraints on collections aren't being enforced. For example, I have:

public class Foo {
@NotEmpty List<String> strings;

 If 'strings' is set to Collections.emptyList() I should get a violation and I do when I call Validator.validate(obj) and Validator.validateProperty(obj, "strings") but not when I call Validator.validateValue(Foo.class, "strings", Collections.emptyList()).

The reason comes down to this snippet at line 2040 of

if (!isIterableOrMap(property.getElementClass())) {
    writeValidatePropertyCall(sw, property, true, false);

The call to writeValidatePropertyCall is only conditional in the Validator.validateValue(...) path.

There seem to be a lot of hidden gotchas with GWT so I'm wondering if there is a reason for the conditional to be there or if it's safe to remove it. I have removed it in my local code and my tests pass just fine but I'm concerned about unintended consequences.

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