Unclear validation error

[axelson]

One of the schemas that we use ExJsonSchema to validate has a top-level anyOf. When there's an error in this schema, we don't get helpful feedback from ExJsonSchema.validate. The error returned is: {:error, [{"Expected any of the schemata to match but none did.", "#"}]}

Here's a script that reproduces the error:

Mix.install([:ex_json_schema, :jason])

schema = """
{
  "$schema": "http://json-schema.org/draft-07/schema#",
  "anyOf": [
    {
      "$ref": "#/$defs/ColumnView"
    }
  ],
  "$defs": {
    "ColumnView": {
      "type": "object",
      "properties": {
        "name": {
          "description": "Column name",
          "type": "string"
        }
      },
      "required": ["name"]
    }
  }
}
"""
|> Jason.decode!()

ExJsonSchema.Validator.validate(schema, %{})
|> IO.inspect()

Instead it would be helpful to have details about why each of the anyOf schemas did not match.

Note: the actual schema is much larger, this is a small reproducible example of the issue

[jonasschmidt]

Hey, the default error formatter doesn't include a lot of detail. When you validate with ExJsonSchema.Validator.validate(schema, %{}, error_formatter: false) you get back error structs that include a lot more information and that can be handled programmatically.