Thomas Countz

module QueryCapturing
  IGNORED_QUERIES = ["SCHEMA", "TRANSACTION"]

  def capture_queries
    captured_queries = []
    subscriber = ActiveSupport::Notifications.subscribe("sql.active_record") do |event|
      captured_queries << event.payload[:sql] unless IGNORED_QUERIES.include?(event.name)
    end
    yield captured_queries
  ensure ActiveSupport::Notifications.unsubscribe(subscriber)
  end
end

class ServiceMetadata::QueryCommentsTest < Minitest::Test
  include QueryCapturing

  def test_annotates_queries_with_metadata_comments
    capture_queries do |queries|
      ServiceMetadata::QueryComments.comment { Comment.all.load }

      assert queries.all? { |q| q.match?(/\/\*.*?origin_service: my_service.*?\*\//m) }
    end
  end
end

def print_progress(title, total, current_progress, bar_width: 50)
  progress_pct = (current_progress.to_f / total) * bar_width
  printf("\r#{title}: [%-#{bar_width}s ] -- %s", "▤" * progress_pct.round, "#{current_progress}/#{total} ")
end

# Usage
1.upto(10) do |i|
  print_progress("Here we go!", 10, i)
  sleep 0.2
end;print("\n")

# Output Example:
# Here we go!: [▤▤▤▤▤▤▤▤▤▤▤▤▤▤▤▤▤▤▤▤▤▤▤▤▤▤▤▤▤▤▤▤▤▤▤                ] -- 7/10

Rails.application.eager_load!

# Instead of all ApplicationRecord descendants, you can
# make an Array of only the models you care about
data = ApplicationRecord.descendants.each_with_object({}) do |model, data|
  model_name = model.name.upcase
  data[model_name] = {
    columns: model.columns.map { |column| [column.name, column.sql_type] },
    associations: model.reflect_on_all_associations.each_with_object({}) do |reflection, assoc_data|
      assoc_data[reflection.name] = {
        klass: reflection.class_name.upcase,
        relationship: reflection.macro
      }
    end
  }
end

# Intermediate step to save the data as JSON
File.open("data.json", "w") { |file| file.write(data.to_json) }

mermaid_erd = ["erDiagram"]

data.each do |table, details|
  columns = details[:columns].map { |name, type| "#{name} #{type}" }.join("\n  ")
  mermaid_erd << "#{table} {\n  #{columns}\n}"
end

data.each do |table, details|
  details[:associations]&.each do |association_name, association_details|
    other_table = association_details[:klass]
    case association_details[:relationship]
    when :belongs_to
      mermaid_erd << "#{table} ||--o{ #{other_table} : \"#{association_name}\""
    when :has_one
      mermaid_erd << "#{table} ||--|| #{other_table} : \"#{association_name}\""
    when :has_many
      mermaid_erd << "#{table} ||--o{ #{other_table} : \"#{association_name}\""
    end
  end
end

File.open("out.mermaid", "w") { |file| file.puts mermaid_erd.join("\n") }