Class: RailsVitals::Playground::Sandbox

Inherits:
Object
  • Object
show all
Defined in:
lib/rails_vitals/playground/sandbox.rb

Defined Under Namespace

Classes: Result

Constant Summary collapse

ALLOWED_METHODS = 
%w[
  all where select limit offset order group
  includes preload eager_load joins left_joins
  find find_by first last count sum average
  pluck distinct having references unscoped
].freeze
BLOCKED_PATTERNS = 
[
  /\b(insert|update|delete|destroy|drop|truncate|create|alter)\b/i,
  /\.save/i, /\.save!/i, /\.update/i, /\.delete/i,
  /\.destroy/i, /`/
].freeze
DEFAULT_LIMIT = 
100

Class Method Summary collapse

Class Method Details

.apply_limit(relation) ⇒ Object 



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# File 'lib/rails_vitals/playground/sandbox.rb', line 162

def self.apply_limit(relation)
  # Only apply default limit if no limit already set
  if relation.limit_value.nil?
    relation.limit(DEFAULT_LIMIT)
  else
    relation
  end
end

.associations_for(model_name) ⇒ Object 



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# File 'lib/rails_vitals/playground/sandbox.rb', line 104

def self.associations_for(model_name)
  model = safe_constantize(model_name)
  return [] unless model

  model.reflect_on_all_associations.map { |r| r.name.to_s }.sort
rescue
  []
end

.available_models ⇒ Object 



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# File 'lib/rails_vitals/playground/sandbox.rb', line 213

def self.available_models
  ActiveRecord::Base.descendants
    .reject(&:abstract_class?)
    .reject { |m| m.name&.start_with?("RailsVitals") }
    .select { |m| m.table_exists? rescue false }
    .map(&:name)
    .sort
end

.blocked_result(message) ⇒ Object 



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# File 'lib/rails_vitals/playground/sandbox.rb', line 205

def self.blocked_result(message)
  Result.new(
    queries: [], query_count: 0, duration_ms: 0,
    error: message, model_name: nil, record_count: 0,
    score: nil, n1_patterns: []
  )
end

.build_binding(model) ⇒ Object 



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# File 'lib/rails_vitals/playground/sandbox.rb', line 155

def self.build_binding(model)
  # Create a minimal binding with only the model exposed
  ctx = Object.new
  ctx.define_singleton_method(:relation) { model.all }
  ctx.instance_eval { binding }
end

.build_relation(expression, model) ⇒ Object 



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# File 'lib/rails_vitals/playground/sandbox.rb', line 134

def self.build_relation(expression, model)
  # Parse "Post.includes(:likes).where(published: true).limit(10)"
  # Strip the model name prefix if present
  chain_str = expression
    .sub(/\A#{Regexp.escape(model.name)}\s*\.?\s*/, "")
    .strip

  return model.all if chain_str.blank?

  # Build the chain by safe eval within a controlled binding
  # Only the model constant is exposed, no access to app globals
  sandbox_binding = build_binding(model)
  relation = eval(chain_str, sandbox_binding) # rubocop:disable Security/Eval

  unless relation.is_a?(ActiveRecord::Relation)
    raise "Expression must return an ActiveRecord::Relation"
  end

  relation
end

.detect_n1(queries) ⇒ Object 



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# File 'lib/rails_vitals/playground/sandbox.rb', line 171

def self.detect_n1(queries)
  normalized = queries.map do |q|
    q[:sql]
      .gsub(/\b\d+\b/, "?")
      .gsub(/'[^']*'/, "?")
      .gsub(/\bIN\s*\([^)]+\)/, "IN (?)")
      .downcase.strip
  end

  normalized
    .tally
    .select { |_, count| count > 1 }
    .map { |sql, count| { pattern: sql, count: count } }
end

.extract_model_name(expression) ⇒ Object 



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# File 'lib/rails_vitals/playground/sandbox.rb', line 113

def self.extract_model_name(expression)
  # Strip comments first
  clean = expression.gsub(/#[^\n]*/, "").strip
  # First word before a dot or whitespace — must look like a constant (CamelCase)
  match = clean.match(/\A([A-Z][A-Za-z0-9]*)/)
  match ? match[1] : nil
end

.project_score(query_count, n1_count) ⇒ Object 



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# File 'lib/rails_vitals/playground/sandbox.rb', line 186

def self.project_score(query_count, n1_count)
  config = RailsVitals.config
  query_score = score_queries(query_count, config)
  n1_score = score_n1(n1_count)
  (query_score * 0.40 + n1_score * 0.60).round
end

.run(expression, access_associations: []) ⇒ Object 



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# File 'lib/rails_vitals/playground/sandbox.rb', line 26

def self.run(expression, access_associations: [])
  return blocked_result("No expression provided") if expression.blank?

  BLOCKED_PATTERNS.each do |pattern|
    return blocked_result(
      "Expression contains blocked operation. " \
      "The Playground is read-only — no writes permitted."
    ) if expression.match?(pattern)
  end

  model_name = extract_model_name(expression)
  return blocked_result(
    "Could not detect model from expression. " \
    "Start your query with a model name e.g. Post.includes(:likes)"
  ) unless model_name

  model = safe_constantize(model_name)
  return blocked_result(
    "Unknown model: #{model_name}. " \
    "Available models: #{available_models.join(', ')}"
  ) unless model

  queries = []
  start_time = Process.clock_gettime(Process::CLOCK_MONOTONIC)

  subscriber = ActiveSupport::Notifications.subscribe("sql.active_record") do |*, payload|
    next if RailsVitals::Notifications::Subscriber.internal_query?(payload[:sql])

    queries << {
      sql: payload[:sql],
      duration_ms: (payload[:duration].to_f / 1000).round(3)
    }
  end

  begin
    Timeout.timeout(2) do
      relation = build_relation(expression, model)
      relation = apply_limit(relation)
      records = relation.load

      # Simulate association access — triggers N+1 if not eager loaded
      if access_associations.any?
        records.each do |record|
          access_associations.each do |assoc|
            next unless record.class.reflect_on_association(assoc.to_sym)
            assoc_value = record.public_send(assoc)
            # Force load if it's a relation
            assoc_value.load if assoc_value.respond_to?(:load)
          end
        end
      end
    end
  rescue Timeout::Error
    return blocked_result("Query timed out after 2 seconds.")
  rescue => e
    return blocked_result("Execution error: #{e.message}")
  ensure
    ActiveSupport::Notifications.unsubscribe(subscriber)
  end

  duration_ms = ((Process.clock_gettime(Process::CLOCK_MONOTONIC) - start_time) * 1000).round(2)
  n1_patterns = detect_n1(queries)
  score = project_score(queries.size, n1_patterns.size)

  Result.new(
    queries: queries,
    query_count: queries.size,
    duration_ms: duration_ms,
    error: nil,
    model_name: model_name,
    record_count: DEFAULT_LIMIT,
    score: score,
    n1_patterns: n1_patterns
  )
rescue => e
  blocked_result("Unexpected error: #{e.message}")
end

.safe_constantize(name) ⇒ Object 



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# File 'lib/rails_vitals/playground/sandbox.rb', line 123

def self.safe_constantize(name)
  return nil unless name.match?(/\A[A-Z][A-Za-z0-9:]*\z/)

  klass = name.constantize
  return nil unless klass < ActiveRecord::Base

  klass
rescue NameError
  nil
end

.score_n1(count) ⇒ Object 



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# File 'lib/rails_vitals/playground/sandbox.rb', line 201

def self.score_n1(count)
  Scorers::NPlusOneScorer.score_for(count)
end

.score_queries(count, config) ⇒ Object 



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# File 'lib/rails_vitals/playground/sandbox.rb', line 193

def self.score_queries(count, config)
  return 100 if count <= config.query_warn_threshold
  return 0   if count >= config.query_critical_threshold

  range = config.query_critical_threshold - config.query_warn_threshold
  (100 - ((count - config.query_warn_threshold).to_f / range * 100)).round
end