Recreate issue with dry-validation

action_controller_main.rb

# frozen_string_literal: true

require "bundler/inline"

gemfile(true) do
  source "https://rubygems.org"

  git_source(:github) { |repo| "https://github.com/#{repo}.git" }

  gem "rails", "6.1.0"
  gem 'dry-validation'
  gem "pry"
  gem 'pry-doc', require: false
  gem 'pry-nav'
  gem 'pry-rails', require: false
end

require "action_controller/railtie"

class TestApp < Rails::Application
  config.root = __dir__
  config.hosts << "example.org"
  secrets.secret_key_base = "secret_key_base"

  config.logger = Logger.new($stdout)
  Rails.logger = config.logger

  routes.draw do
    post "fax", to: "test#create"
  end
end

class TestController < ActionController::Base
  include Rails.application.routes.url_helpers

  class BulkSendContract < Dry::Validation::Contract
    params do
      required(:send_params).array(:hash) do
        required(:id).value(:integer)
        required(:recipients).array(:string)
      end
    end

    rule("send_params").each do
      recipients = value[:recipients]
      recipients.each do |recipient|
        stripped_value = recipient.gsub(/[-()\s]/, '')
        key.failure("Fax number '#{recipient}' has invalid format") unless stripped_value =~ /^\+?[0-9]{6,}$/
      end
    end

    # rule("send_params.recipients").each do
    #   ::Kernel.binding.pry
    #   stripped_value = value.gsub(/[-()\s]/, '')
    #   key.failure("Fax number '#{recipient}' has invalid format") unless stripped_value =~ /^\+?[0-9]{6,}$/
    # end
  end

  def create
    input = BulkSendContract.new.call(params.to_unsafe_h)
    return render json: { errors: input.errors.to_h } if input.errors.any?
    render json: { status: "OK" }
  end
end

require "minitest/autorun"
require "rack/test"

class BugTest < Minitest::Test
  include Rack::Test::Methods

  def test_returns_success
    send_params = [{ id: 1, recipients: ["2", ["2", "1"]] }]
    # send_params = [{ id: 1, recipients: ["2"] }]
    post "fax", { send_params: send_params }.to_json, { "CONTENT_TYPE" => "application/json" }
    expected = { "errors" => { "send_params" => { "0" => { "recipients" => ["must be a string"] } } } }
    assert_equal expected, JSON.parse(last_response.body)
  end

  private

  def app
    Rails.application
  end
end