Dry::Validation::Contract behaves different when defined with a params Dry::Schema::Params(parent: RawSchema) vs. params ParamsSchema

[postmodern]

Describe the bug

When Dry::Validation::Contract contains params Dry::Schema::Params(parent: RawSchema) (where RawSchema is defined using Dry::Schema.define do ... end), it fails to coerce empty Strings into Integers. However, if I define a ParamsSchema using Dry::Schema::Params() do ... end containing the same param definitions, and add params ParamsSchema to my Dry::Validation::Contract class, it works as expected.

To Reproduce

require 'dry/types'
require 'dry/schema'
require 'dry/validation'

module Types
  include Dry::Types()
end

RawSchema = Dry::Schema.define do
  required(:foo).filled(:string)
  optional(:bar).maybe(:integer)
end

ParamsSchema = Dry::Schema::Params() do
  required(:foo).filled(:string)
  optional(:bar).maybe(:integer)
end

class WrappedParamsSchemaValidation < Dry::Validation::Contract

  params Dry::Schema::Params(parent: RawSchema)

end

class ParamsSchemaValidation < Dry::Validation::Contract

  params ParamsSchema

end

params = {"foo" => "a", "bar" => ""}

p WrappedParamsSchemaValidation.new.call(params)
p ParamsSchemaValidation.new.call(params)

Expected behavior

#<Dry::Validation::Result{:foo=>"a", :bar=>nil} errors={}>
#<Dry::Validation::Result{:foo=>"a", :bar=>nil} errors={}>

Actual behavior

#<Dry::Validation::Result{:foo=>"a", :bar=>""} errors={:bar=>["must be an integer"]}>
#<Dry::Validation::Result{:foo=>"a", :bar=>nil} errors={}>

My environment

• Affects my production application: NO (the app is not running in production)
• Ruby version: ruby 3.1.3p185 (2022-11-24 revision 1a6b16756e) [x86_64-linux]
• dry-types: 1.7.1
• dry-schema: 1.13.1
• dry-validation: 1.10.0

[solnic]

Oh interesting. This does look like a bug because using params should preset processor to use params coercion regardless of the parent schema. Thanks for reporting this, good catch.

[postmodern]

@solnic what's your rough estimation for how long it will take to find and fix this bug? Obviously being forced to duplicate the parent schema for both mapping in both HTTP params and a JSON Hash isn't ideal, although it's the only workaround I found.