Maintain json schema error properties when using custom validation

[RoboPhred]

This is a fix for 1.x. After it lands, I will cherry-pick to 2.x and adjust as nescessary.

Reasons for making this change

As described in #1596

Enabling custom validation strips json schema errors of useful properties such as "property", "params", and "schemaPath". All properties save "stack" are removed, preventing the error consumer from knowing where the error occurred or what rule it validated.

Additionally, custom errors do not provide a "property" prop, so the error consumer likewise does not know what property is encountering the custom error, just that the error happened 'somewhere'.

This PR fixes both these issues:

JSON Schema errors now keep their properties in the presence of custom validation. This is done by not regenerating the entire error list, but instead keeping the old list and appending the custom errors to this list.

For custom errors, this PR modifies toErrorList to track the path of the error and generate a property prop containing the property path to the property that encountered the error.

I am not adding documentation, as the actual format of the onError errors array seems to be undocumented. I can attempt to fill in some of the gaps here if you want to adopt the current ajv error objects as official api.

Checklist

• I'm updating documentation
  • I've checked the rendering of the Markdown text I've added
• I'm adding or updating code
  • I've added and/or updated tests
  • I've updated docs if needed
• I'm adding a new feature
  • I've updated the playground with an example use of the feature

[epicfaace]

@RoboPhred thanks for the PR. Could you actually make this PR to master instead? Would like to keep updates to v1.x to be minimal changes such as security vulnerability fixes if possible.

Additionally, can you add a test that ensures that the error properties are maintained?

[bmmpt]

@epicfaace Any reason why this has gone stale? Is it the lack of unit tests?

[bmmpt]

@epicfaace thanks for the thumbs up and forgive my persistence. I don't mean to be pushy, but I didn't really get an answer to any of my questions.

[epicfaace]

Additionally, can you add a test that ensures that the error properties are maintained?

Yeah, it's the lack of unit tests, and also the fact that this PR isn't to the master branch.

[bmmpt]

@epicfaace Thanks for the quick response. This is something that I will need pretty soon and was even considering forking and rolling with forked code until this is completed. Instead of that, as soon as I have a few minutes I will add the missing tests if no one beats me to it.

[bmmpt]

@epicfaace I have been too busy to be able to get to this, but I asked a colleague of mine to look into it and he created a PR into master: #2242

[epicfaace]

Additionally, can you add a test that ensures that the error properties are maintained?

Yeah, it's the lack of unit tests, and also the fact that this PR isn't to the master branch.

@bmmpt , sorry, I forgot about this PR at the time of the comment (#2002). I'm going to close this PR for now, @RoboPhred , so we can focus on the PR #2002 to master.