Class: PostHog::FeatureFlagsPoller

Inherits:
Object
  • Object
show all
Includes:
Logging, Utils
Defined in:
lib/posthog/feature_flags.rb

Constant Summary

Constants included from Utils

Utils::UTC_OFFSET_WITHOUT_COLON, Utils::UTC_OFFSET_WITH_COLON

Class Method Summary collapse

Instance Method Summary collapse

Methods included from Utils

convert_to_datetime, date_in_iso8601, datetime_in_iso8601, formatted_offset, get_by_symbol_or_string_key, is_valid_regex, isoify_dates, isoify_dates!, seconds_to_utc_offset, stringify_keys, symbolize_keys, symbolize_keys!, time_in_iso8601, uid

Methods included from Logging

included, #logger

Constructor Details

#initialize(polling_interval, personal_api_key, project_api_key, host, feature_flag_request_timeout_seconds, on_error = nil) ⇒ FeatureFlagsPoller 



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# File 'lib/posthog/feature_flags.rb', line 26

def initialize(
  polling_interval,
  personal_api_key,
  project_api_key,
  host,
  feature_flag_request_timeout_seconds,
  on_error = nil
)
  @polling_interval = polling_interval || 30
  @personal_api_key = personal_api_key
  @project_api_key = project_api_key
  @host = host
  @feature_flags = Concurrent::Array.new
  @group_type_mapping = Concurrent::Hash.new
  @cohorts = Concurrent::Hash.new
  @loaded_flags_successfully_once = Concurrent::AtomicBoolean.new
  @feature_flags_by_key = nil
  @feature_flag_request_timeout_seconds = feature_flag_request_timeout_seconds
  @on_error = on_error || proc { |status, error| }
  @quota_limited = Concurrent::AtomicBoolean.new(false)
  @flags_etag = Concurrent::AtomicReference.new(nil)
  @task =
    Concurrent::TimerTask.new(
      execution_interval: polling_interval
    ) { _load_feature_flags }

  # If no personal API key, disable local evaluation & thus polling for definitions
  if @personal_api_key.nil?
    logger.info 'No personal API key provided, disabling local evaluation'
    @loaded_flags_successfully_once.make_true
  else
    # load once before timer
    load_feature_flags
    @task.execute
  end
end

Class Method Details

.compare(lhs, rhs, operator) ⇒ Object

Class methods



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# File 'lib/posthog/feature_flags.rb', line 379

def self.compare(lhs, rhs, operator)
  case operator
  when 'gt'
    lhs > rhs
  when 'gte'
    lhs >= rhs
  when 'lt'
    lhs < rhs
  when 'lte'
    lhs <= rhs
  else
    raise "Invalid operator: #{operator}"
  end
end

.match_cohort(property, property_values, cohort_properties) ⇒ Object 



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# File 'lib/posthog/feature_flags.rb', line 631

def self.match_cohort(property, property_values, cohort_properties)
  # Cohort properties are in the form of property groups like this:
  # {
  #   "cohort_id" => {
  #     "type" => "AND|OR",
  #     "values" => [{
  #        "key" => "property_name", "value" => "property_value"
  #     }]
  #   }
  # }
  cohort_id = extract_value(property, :value).to_s
  property_group = find_cohort_property(cohort_properties, cohort_id)

  unless property_group
    raise RequiresServerEvaluation,
          "cohort #{cohort_id} not found in local cohorts - likely a static cohort that requires server evaluation"
  end

  match_property_group(property_group, property_values, cohort_properties)
end

.match_property(property, property_values, cohort_properties = {}) ⇒ Object 



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# File 'lib/posthog/feature_flags.rb', line 522

def self.match_property(property, property_values, cohort_properties = {})
  # only looks for matches where key exists in property_values
  # doesn't support operator is_not_set

  PostHog::Utils.symbolize_keys! property
  PostHog::Utils.symbolize_keys! property_values

  # Handle cohort properties
  return match_cohort(property, property_values, cohort_properties) if extract_value(property, :type) == 'cohort'

  key = property[:key].to_sym
  value = property[:value]
  operator = property[:operator] || 'exact'

  if !property_values.key?(key)
    raise InconclusiveMatchError, "Property #{key} not found in property_values"
  elsif operator == 'is_not_set'
    raise InconclusiveMatchError, 'Operator is_not_set not supported'
  end

  override_value = property_values[key]

  case operator
  when 'exact', 'is_not'
    if value.is_a?(Array)
      values_stringified = value.map { |val| val.to_s.downcase }
      return values_stringified.any?(override_value.to_s.downcase) if operator == 'exact'

      return values_stringified.none?(override_value.to_s.downcase)

    end
    if operator == 'exact'
      value.to_s.downcase == override_value.to_s.downcase
    else
      value.to_s.downcase != override_value.to_s.downcase
    end
  when 'is_set'
    property_values.key?(key)
  when 'icontains'
    override_value.to_s.downcase.include?(value.to_s.downcase)
  when 'not_icontains'
    !override_value.to_s.downcase.include?(value.to_s.downcase)
  when 'regex'
    PostHog::Utils.is_valid_regex(value.to_s) && !Regexp.new(value.to_s).match(override_value.to_s).nil?
  when 'not_regex'
    PostHog::Utils.is_valid_regex(value.to_s) && Regexp.new(value.to_s).match(override_value.to_s).nil?
  when 'gt', 'gte', 'lt', 'lte'
    parsed_value = nil
    begin
      parsed_value = Float(value)
    rescue StandardError # rubocop:disable Lint/SuppressedException
    end
    if !parsed_value.nil? && !override_value.nil?
      if override_value.is_a?(String)
        compare(override_value, value.to_s, operator)
      else
        compare(override_value, parsed_value, operator)
      end
    else
      compare(override_value.to_s, value.to_s, operator)
    end
  when 'is_date_before', 'is_date_after'
    override_date = PostHog::Utils.convert_to_datetime(override_value.to_s)
    parsed_date = relative_date_parse_for_feature_flag_matching(value.to_s)

    parsed_date = PostHog::Utils.convert_to_datetime(value.to_s) if parsed_date.nil?

    raise InconclusiveMatchError, 'Invalid date format' unless parsed_date

    if operator == 'is_date_before'
      override_date < parsed_date
    elsif operator == 'is_date_after'
      override_date > parsed_date
    end
  when 'semver_eq', 'semver_neq', 'semver_gt', 'semver_gte', 'semver_lt', 'semver_lte'
    override_parsed = parse_semver(override_value)
    flag_parsed = parse_semver(value)

    case operator
    when 'semver_eq'
      override_parsed == flag_parsed
    when 'semver_neq'
      override_parsed != flag_parsed
    when 'semver_gt'
      (override_parsed <=> flag_parsed) == 1
    when 'semver_gte'
      (override_parsed <=> flag_parsed) >= 0
    when 'semver_lt'
      (override_parsed <=> flag_parsed) == -1
    when 'semver_lte'
      (override_parsed <=> flag_parsed) <= 0
    end
  when 'semver_tilde'
    override_parsed = parse_semver(override_value)
    lower, upper = semver_tilde_bounds(value)
    (override_parsed <=> lower) >= 0 && (override_parsed <=> upper) == -1
  when 'semver_caret'
    override_parsed = parse_semver(override_value)
    lower, upper = semver_caret_bounds(value)
    (override_parsed <=> lower) >= 0 && (override_parsed <=> upper) == -1
  when 'semver_wildcard'
    override_parsed = parse_semver(override_value)
    lower, upper = semver_wildcard_bounds(value)
    (override_parsed <=> lower) >= 0 && (override_parsed <=> upper) == -1
  else
    raise InconclusiveMatchError, "Unknown operator: #{operator}"
  end
end

.match_property_group(property_group, property_values, cohort_properties) ⇒ Object 



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# File 'lib/posthog/feature_flags.rb', line 652

def self.match_property_group(property_group, property_values, cohort_properties)
  return true if property_group.nil? || property_group.empty?

  group_type = extract_value(property_group, :type)
  properties = extract_value(property_group, :values)

  return true if properties.nil? || properties.empty?

  if nested_property_group?(properties)
    match_nested_property_group(properties, group_type, property_values, cohort_properties)
  else
    match_regular_property_group(properties, group_type, property_values, cohort_properties)
  end
end

.matches_dependency_value(expected_value, actual_value) ⇒ Object 



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# File 'lib/posthog/feature_flags.rb', line 830

def self.matches_dependency_value(expected_value, actual_value)
  # Check if the actual flag value matches the expected dependency value.
  #
  # - String variant case: check for exact match or boolean true
  # - Boolean case: must match expected boolean value
  #
  # @param expected_value [Object] The expected value from the property
  # @param actual_value [Object] The actual value returned by the flag evaluation
  # @return [Boolean] True if the values match according to flag dependency rules

  # String variant case - check for exact match or boolean true
  if actual_value.is_a?(String) && !actual_value.empty?
    if expected_value.is_a?(TrueClass) || expected_value.is_a?(FalseClass)
      # Any variant matches boolean true
      return expected_value
    elsif expected_value.is_a?(String)
      # variants are case-sensitive, hence our comparison is too
      return actual_value == expected_value
    else
      return false
    end

  # Boolean case - must match expected boolean value
  elsif actual_value.is_a?(TrueClass) || actual_value.is_a?(FalseClass)
    return actual_value == expected_value if expected_value.is_a?(TrueClass) || expected_value.is_a?(FalseClass)
  end

  # Default case
  false
end

.parse_semver(value) ⇒ Object

Parse a semver string into a comparable [major, minor, patch] integer array. Handles v-prefix, whitespace, pre-release suffixes. Defaults missing components to 0.

Raises:



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# File 'lib/posthog/feature_flags.rb', line 427

def self.parse_semver(value)
  raise InconclusiveMatchError, 'Invalid semver format' if value.nil?

  text = value.to_s.strip.sub(/^[vV]/, '')

  raise InconclusiveMatchError, 'Invalid semver format' if text.empty?

  # Strip pre-release and build metadata suffixes
  text = text.split('-')[0].split('+')[0]
  parts = text.split('.')

  raise InconclusiveMatchError, 'Invalid semver format' if parts.empty? || parts[0].to_s.empty?

  # Check for leading dot or non-numeric parts
  parts.each do |part|
    raise InconclusiveMatchError, 'Invalid semver format' if part.empty? || part !~ /^\d+$/
  end

  major = parts[0].to_i
  minor = parts.length > 1 ? parts[1].to_i : 0
  patch = parts.length > 2 ? parts[2].to_i : 0

  [major, minor, patch]
end

.relative_date_parse_for_feature_flag_matching(value) ⇒ Object 



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# File 'lib/posthog/feature_flags.rb', line 394

def self.relative_date_parse_for_feature_flag_matching(value)
  match = /^-?([0-9]+)([a-z])$/.match(value)
  parsed_dt = DateTime.now.new_offset(0)
  return unless match

  number = match[1].to_i

  if number >= 10_000
    # Guard against overflow, disallow numbers greater than 10_000
    return nil
  end

  interval = match[2]
  case interval
  when 'h'
    parsed_dt -= (number / 24.0)
  when 'd'
    parsed_dt = parsed_dt.prev_day(number)
  when 'w'
    parsed_dt = parsed_dt.prev_day(number * 7)
  when 'm'
    parsed_dt = parsed_dt.prev_month(number)
  when 'y'
    parsed_dt = parsed_dt.prev_year(number)
  else
    return nil
  end

  parsed_dt
end

.semver_caret_bounds(value) ⇒ Object

Returns bounds for caret (^) range per semver spec: ^X.Y.Z where X > 0 → >=X.Y.Z <(X+1).0.0 ^0.Y.Z where Y > 0 → >=0.Y.Z <0.(Y+1).0 ^0.0.Z → >=0.0.Z <0.0.(Z+1)



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# File 'lib/posthog/feature_flags.rb', line 480

def self.semver_caret_bounds(value)
  major, minor, patch = parse_semver(value)
  lower = [major, minor, patch]

  upper = if major.positive?
            [major + 1, 0, 0]
          elsif minor.positive?
            [0, minor + 1, 0]
          else
            [0, 0, patch + 1]
          end

  [lower, upper]
end

.semver_tilde_bounds(value) ⇒ Object

Returns bounds for tilde (~) range: ~X → >=X.0.0 <(X+1).0.0 ~X.Y → >=X.Y.0 <X.(Y+1).0 ~X.Y.Z → >=X.Y.Z <X.(Y+1).0



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# File 'lib/posthog/feature_flags.rb', line 456

def self.semver_tilde_bounds(value)
  major, minor, patch = parse_semver(value)
  lower = [major, minor, patch]

  # Determine how many components were provided
  text = value.to_s.strip.sub(/^[vV]/, '')
  text = text.split('-')[0].split('+')[0]
  component_count = text.split('.').length

  upper = if component_count == 1
            # Major-only: bump major
            [major + 1, 0, 0]
          else
            # Major.minor or major.minor.patch: bump minor
            [major, minor + 1, 0]
          end

  [lower, upper]
end

.semver_wildcard_bounds(value) ⇒ Object

Returns bounds for wildcard (*) range: X.* or X → >=X.0.0 <(X+1).0.0 X.Y.* → >=X.Y.0 <X.(Y+1).0

Raises:



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# File 'lib/posthog/feature_flags.rb', line 498

def self.semver_wildcard_bounds(value)
  cleaned = value.to_s.strip.sub(/^[vV]/, '').gsub('*', '').chomp('.')
  parts = cleaned.split('.').reject(&:empty?)

  raise InconclusiveMatchError, 'Invalid semver wildcard format' if parts.empty?

  parts.each do |part|
    raise InconclusiveMatchError, 'Invalid semver wildcard format' if part !~ /^\d+$/
  end

  major = parts[0].to_i
  case parts.length
  when 1
    [[major, 0, 0], [major + 1, 0, 0]]
  when 2
    minor = parts[1].to_i
    [[major, minor, 0], [major, minor + 1, 0]]
  else
    minor = parts[1].to_i
    patch = parts[2].to_i
    [[major, minor, patch], [major, minor, patch + 1]]
  end
end

Instance Method Details

#_compute_flag_locally(flag, distinct_id, groups = {}, person_properties = {}, group_properties = {}) ⇒ Object

Raises:



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# File 'lib/posthog/feature_flags.rb', line 864

def _compute_flag_locally(flag, distinct_id, groups = {}, person_properties = {}, group_properties = {})
  raise RequiresServerEvaluation, 'Flag has experience continuity enabled' if flag[:ensure_experience_continuity]

  return false unless flag[:active]

  # Create evaluation cache for flag dependencies
  evaluation_cache = {}

  flag_filters = flag[:filters] || {}

  aggregation_group_type_index = flag_filters[:aggregation_group_type_index]
  if aggregation_group_type_index.nil?
    return match_feature_flag_properties(flag, distinct_id, person_properties, evaluation_cache, @cohorts)
  end

  group_name = @group_type_mapping[aggregation_group_type_index.to_s.to_sym]

  if group_name.nil?
    logger.warn(
      "[FEATURE FLAGS] Unknown group type index #{aggregation_group_type_index} for feature flag #{flag[:key]}"
    )
    # failover to `/flags/`
    raise InconclusiveMatchError, 'Flag has unknown group type index'
  end

  group_name_symbol = group_name.to_sym

  unless groups.key?(group_name_symbol)
    # Group flags are never enabled if appropriate `groups` aren't passed in
    # don't failover to `/flags/`, since response will be the same
    logger.warn "[FEATURE FLAGS] Can't compute group feature flag: #{flag[:key]} without group names passed in"
    return false
  end

  focused_group_properties = group_properties[group_name_symbol]
  match_feature_flag_properties(flag, groups[group_name_symbol], focused_group_properties, evaluation_cache,
                                @cohorts)
end

#_compute_flag_payload_locally(key, match_value) ⇒ Object 



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# File 'lib/posthog/feature_flags.rb', line 903

def _compute_flag_payload_locally(key, match_value)
  return nil if @feature_flags_by_key.nil?

  response = nil
  if [true, false].include? match_value
    response = @feature_flags_by_key.dig(key, :filters, :payloads, match_value.to_s.to_sym)
  elsif match_value.is_a? String
    response = @feature_flags_by_key.dig(key, :filters, :payloads, match_value.to_sym)
  end
  response
end

#_hash(key, distinct_id, salt = '') ⇒ Object

This function takes a distinct_id and a feature flag key and returns a float between 0 and 1. Given the same distinct_id and key, it’ll always return the same float. These floats are uniformly distributed between 0 and 1, so if we want to show this feature to 20% of traffic we can do _hash(key, distinct_id) < 0.2



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# File 'lib/posthog/feature_flags.rb', line 981

def _hash(key, distinct_id, salt = '')
  hash_key = Digest::SHA1.hexdigest "#{key}.#{distinct_id}#{salt}"
  (Integer(hash_key[0..14], 16).to_f / 0xfffffffffffffff)
end

#_load_feature_flags ⇒ Object 



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# File 'lib/posthog/feature_flags.rb', line 1008

def _load_feature_flags
  begin
    res = _request_feature_flag_definitions(etag: @flags_etag.value)
  rescue StandardError => e
    @on_error.call(-1, e.to_s)
    return
  end

  # Handle 304 Not Modified - flags haven't changed, skip processing
  # Only update ETag if the 304 response includes one
  if res[:not_modified]
    @flags_etag.value = res[:etag] if res[:etag]
    logger.debug '[FEATURE FLAGS] Flags not modified (304), using cached data'
    return
  end

  # Handle quota limits with 402 status
  if res.is_a?(Hash) && res[:status] == 402
    logger.warn(
      '[FEATURE FLAGS] Feature flags quota limit exceeded - unsetting all local flags. ' \
      'Learn more about billing limits at https://posthog.com/docs/billing/limits-alerts'
    )
    @feature_flags = Concurrent::Array.new
    @feature_flags_by_key = {}
    @group_type_mapping = Concurrent::Hash.new
    @cohorts = Concurrent::Hash.new
    @loaded_flags_successfully_once.make_false
    @quota_limited.make_true
    return
  end

  if res.key?(:flags)
    # Only update ETag on successful responses with flag data
    @flags_etag.value = res[:etag]

    @feature_flags = res[:flags] || []
    @feature_flags_by_key = {}
    @feature_flags.each do |flag|
      @feature_flags_by_key[flag[:key]] = flag unless flag[:key].nil?
    end
    @group_type_mapping = res[:group_type_mapping] || {}
    @cohorts = res[:cohorts] || {}

    logger.debug "Loaded #{@feature_flags.length} feature flags and #{@cohorts.length} cohorts"
    @loaded_flags_successfully_once.make_true if @loaded_flags_successfully_once.false?
  else
    logger.debug "Failed to load feature flags: #{res}"
  end
end

#_mask_tokens_in_url(url) ⇒ Object

rubocop:enable Lint/ShadowedException



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# File 'lib/posthog/feature_flags.rb', line 1140

def _mask_tokens_in_url(url)
  url.gsub(/token=([^&]{10})[^&]*/, 'token=\1...')
end

#_request(uri, request_object, timeout = nil, include_etag: false) ⇒ Object

rubocop:disable Lint/ShadowedException



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# File 'lib/posthog/feature_flags.rb', line 1089

def _request(uri, request_object, timeout = nil, include_etag: false)
  request_object['User-Agent'] = "posthog-ruby#{PostHog::VERSION}"
  request_timeout = timeout || 10

  begin
    Net::HTTP.start(
      uri.hostname,
      uri.port,
      use_ssl: uri.scheme == 'https',
      read_timeout: request_timeout
    ) do |http|
      res = http.request(request_object)
      status_code = res.code.to_i
      etag = include_etag ? res['ETag'] : nil

      # Handle 304 Not Modified - return special response indicating no change
      if status_code == 304
        logger.debug("#{request_object.method} #{_mask_tokens_in_url(uri.to_s)} returned 304 Not Modified")
        return { not_modified: true, etag: etag, status: status_code }
      end

      # Parse response body to hash
      begin
        response = JSON.parse(res.body, { symbolize_names: true })
        # Only add status (and etag if requested) if response is a hash
        extra_fields = { status: status_code }
        extra_fields[:etag] = etag if include_etag
        response = response.merge(extra_fields) if response.is_a?(Hash)
        return response
      rescue JSON::ParserError
        # Handle case when response isn't valid JSON
        error_response = { error: 'Invalid JSON response', body: res.body, status: status_code }
        error_response[:etag] = etag if include_etag
        return error_response
      end
    end
  rescue Timeout::Error,
         Errno::EINVAL,
         Errno::ECONNRESET,
         EOFError,
         Net::HTTPBadResponse,
         Net::HTTPHeaderSyntaxError,
         Net::ReadTimeout,
         Net::WriteTimeout,
         Net::ProtocolError
    logger.debug("Unable to complete request to #{uri}")
    raise
  end
end

#_request_feature_flag_definitions(etag: nil) ⇒ Object 



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# File 'lib/posthog/feature_flags.rb', line 1058

def _request_feature_flag_definitions(etag: nil)
  uri = URI("#{@host}/api/feature_flag/local_evaluation")
  uri.query = URI.encode_www_form([['token', @project_api_key], %w[send_cohorts true]])
  req = Net::HTTP::Get.new(uri)
  req['Authorization'] = "Bearer #{@personal_api_key}"
  req['If-None-Match'] = etag if etag

  _request(uri, req, nil, include_etag: true)
end

#_request_feature_flag_evaluation(data = {}) ⇒ Object 



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# File 'lib/posthog/feature_flags.rb', line 1068

def _request_feature_flag_evaluation(data = {})
  uri = URI("#{@host}/flags/?v=2")
  req = Net::HTTP::Post.new(uri)
  req['Content-Type'] = 'application/json'
  data['token'] = @project_api_key
  req.body = data.to_json

  _request(uri, req, @feature_flag_request_timeout_seconds)
end

#_request_remote_config_payload(flag_key) ⇒ Object 



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# File 'lib/posthog/feature_flags.rb', line 1078

def _request_remote_config_payload(flag_key)
  uri = URI("#{@host}/api/projects/@current/feature_flags/#{flag_key}/remote_config")
  uri.query = URI.encode_www_form([['token', @project_api_key]])
  req = Net::HTTP::Get.new(uri)
  req['Content-Type'] = 'application/json'
  req['Authorization'] = "Bearer #{@personal_api_key}"

  _request(uri, req, @feature_flag_request_timeout_seconds)
end

#condition_match(flag, distinct_id, condition, properties, evaluation_cache, cohort_properties = {}) ⇒ Object 



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# File 'lib/posthog/feature_flags.rb', line 955

def condition_match(flag, distinct_id, condition, properties, evaluation_cache, cohort_properties = {})
  rollout_percentage = condition[:rollout_percentage]

  unless (condition[:properties] || []).empty?
    unless condition[:properties].all? do |prop|
      if prop[:type] == 'flag'
        evaluate_flag_dependency(prop, evaluation_cache, distinct_id, properties, cohort_properties)
      else
        FeatureFlagsPoller.match_property(prop, properties, cohort_properties)
      end
    end
      return false
    end

    return true if rollout_percentage.nil?
  end

  return false if !rollout_percentage.nil? && (_hash(flag[:key], distinct_id) > (rollout_percentage.to_f / 100))

  true
end

#evaluate_flag_dependency(property, evaluation_cache, distinct_id, properties, cohort_properties) ⇒ Boolean

Evaluates a flag dependency property according to the dependency chain algorithm.



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# File 'lib/posthog/feature_flags.rb', line 747

def evaluate_flag_dependency(property, evaluation_cache, distinct_id, properties, cohort_properties)
  if property[:operator] != 'flag_evaluates_to'
    # Should never happen, but just in case
    raise InconclusiveMatchError, "Operator #{property[:operator]} not supported for flag dependencies"
  end

  if @feature_flags_by_key.nil? || evaluation_cache.nil?
    # Cannot evaluate flag dependencies without required context
    raise InconclusiveMatchError,
          "Cannot evaluate flag dependency on '#{property[:key] || 'unknown'}' " \
          'without feature flags loaded or evaluation_cache'
  end

  # Check if dependency_chain is present - it should always be provided for flag dependencies
  unless property.key?(:dependency_chain)
    # Missing dependency_chain indicates malformed server data
    raise InconclusiveMatchError,
          "Flag dependency property for '#{property[:key] || 'unknown'}' " \
          "is missing required 'dependency_chain' field"
  end

  dependency_chain = property[:dependency_chain]

  # Handle circular dependency (empty chain means circular)
  if dependency_chain.empty?
    PostHog::Logging.logger&.debug("Circular dependency detected for flag: #{property[:key]}")
    raise InconclusiveMatchError,
          "Circular dependency detected for flag '#{property[:key] || 'unknown'}'"
  end

  # Evaluate all dependencies in the chain order
  dependency_chain.each do |dep_flag_key|
    unless evaluation_cache.key?(dep_flag_key)
      # Need to evaluate this dependency first
      dep_flag = @feature_flags_by_key[dep_flag_key]
      if dep_flag.nil?
        # Missing flag dependency - cannot evaluate locally
        evaluation_cache[dep_flag_key] = nil
        raise InconclusiveMatchError,
              "Cannot evaluate flag dependency '#{dep_flag_key}' - flag not found in local flags"
      elsif !dep_flag[:active]
        # Check if the flag is active (same check as in _compute_flag_locally)
        evaluation_cache[dep_flag_key] = false
      else
        # Recursively evaluate the dependency using existing instance method
        begin
          dep_result = match_feature_flag_properties(
            dep_flag,
            distinct_id,
            properties,
            evaluation_cache,
            cohort_properties
          )
          evaluation_cache[dep_flag_key] = dep_result
        rescue InconclusiveMatchError => e
          # If we can't evaluate a dependency, store nil and propagate the error
          evaluation_cache[dep_flag_key] = nil
          raise InconclusiveMatchError,
                "Cannot evaluate flag dependency '#{dep_flag_key}': #{e.message}"
        end
      end
    end

    # Check the cached result
    cached_result = evaluation_cache[dep_flag_key]
    if cached_result.nil?
      # Previously inconclusive - raise error again
      raise InconclusiveMatchError,
            "Flag dependency '#{dep_flag_key}' was previously inconclusive"
    elsif !cached_result
      # Definitive False result - dependency failed
      return false
    end
  end

  # Get the expected value of the immediate dependency and the actual value
  expected_value = property[:value]
  # The flag we want to evaluate is defined by :key which should ALSO be the last key in the dependency chain
  actual_value = evaluation_cache[property[:key]]

  self.class.matches_dependency_value(expected_value, actual_value)
end

#get_all_flags(distinct_id, groups = {}, person_properties = {}, group_properties = {}, only_evaluate_locally = false) ⇒ Object 



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# File 'lib/posthog/feature_flags.rb', line 238

def get_all_flags(
  distinct_id,
  groups = {},
  person_properties = {},
  group_properties = {},
  only_evaluate_locally = false
)
  if @quota_limited.true?
    logger.debug 'Not fetching flags from server - quota limited'
    return {}
  end

  # returns a string hash of all flags
  response = get_all_flags_and_payloads(
    distinct_id,
    groups,
    person_properties,
    group_properties,
    only_evaluate_locally
  )

  response[:featureFlags]
end

#get_all_flags_and_payloads(distinct_id, groups = {}, person_properties = {}, group_properties = {}, only_evaluate_locally = false, raise_on_error = false) ⇒ Object 



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# File 'lib/posthog/feature_flags.rb', line 262

def get_all_flags_and_payloads(
  distinct_id,
  groups = {},
  person_properties = {},
  group_properties = {},
  only_evaluate_locally = false,
  raise_on_error = false
)
  load_feature_flags

  flags = {}
  payloads = {}
  fallback_to_server = @feature_flags.empty?
  request_id = nil # Only for /flags requests
  evaluated_at = nil # Only for /flags requests

  @feature_flags.each do |flag|
    match_value = _compute_flag_locally(flag, distinct_id, groups, person_properties, group_properties)
    flags[flag[:key]] = match_value
    match_payload = _compute_flag_payload_locally(flag[:key], match_value)
    payloads[flag[:key]] = match_payload if match_payload
  rescue RequiresServerEvaluation, InconclusiveMatchError
    fallback_to_server = true
  rescue StandardError => e
    @on_error.call(-1, "Error computing flag locally: #{e}. #{e.backtrace.join("\n")} ")
    fallback_to_server = true
  end

  errors_while_computing = false
  quota_limited = nil
  status_code = nil

  if fallback_to_server && !only_evaluate_locally
    begin
      flags_and_payloads = get_flags(distinct_id, groups, person_properties, group_properties)
      errors_while_computing = flags_and_payloads[:errorsWhileComputingFlags] || false
      quota_limited = flags_and_payloads[:quotaLimited]
      status_code = flags_and_payloads[:status]

      unless flags_and_payloads.key?(:featureFlags)
        raise StandardError, "Error flags response: #{flags_and_payloads}"
      end

      request_id = flags_and_payloads[:requestId]
      evaluated_at = flags_and_payloads[:evaluatedAt]

      # Check if feature_flags are quota limited
      if quota_limited&.include?('feature_flags')
        logger.warn '[FEATURE FLAGS] Quota limited for feature flags'
        flags = {}
        payloads = {}
      else
        server_flags = stringify_keys(flags_and_payloads[:featureFlags] || {})
        server_payloads = stringify_keys(flags_and_payloads[:featureFlagPayloads] || {})

        if errors_while_computing
          # Merge server results into locally-evaluated results so that flags which
          # failed server-side evaluation (already filtered out by get_flags) don't
          # overwrite valid locally-evaluated values.
          flags = stringify_keys(flags).merge(server_flags)
          payloads = stringify_keys(payloads).merge(server_payloads)
        else
          flags = server_flags
          payloads = server_payloads
        end
      end
    rescue StandardError => e
      @on_error.call(-1, "Error computing flag remotely: #{e}")
      raise if raise_on_error
    end
  end

  {
    featureFlags: flags,
    featureFlagPayloads: payloads,
    requestId: request_id,
    evaluatedAt: evaluated_at,
    errorsWhileComputingFlags: errors_while_computing,
    quotaLimited: quota_limited,
    status: status_code
  }
end

#get_feature_flag(key, distinct_id, groups = {}, person_properties = {}, group_properties = {}, only_evaluate_locally = false) ⇒ Object 



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# File 'lib/posthog/feature_flags.rb', line 154

def get_feature_flag(
  key,
  distinct_id,
  groups = {},
  person_properties = {},
  group_properties = {},
  only_evaluate_locally = false
)
  # make sure they're loaded on first run
  load_feature_flags

  symbolize_keys! groups
  symbolize_keys! person_properties
  symbolize_keys! group_properties

  group_properties.each_value do |value|
    symbolize_keys!(value)
  end

  response = nil
  payload = nil
  feature_flag = @feature_flags_by_key&.[](key)

  unless feature_flag.nil?
    begin
      response = _compute_flag_locally(feature_flag, distinct_id, groups, person_properties, group_properties)
      payload = _compute_flag_payload_locally(key, response) unless response.nil?
      logger.debug "Successfully computed flag locally: #{key} -> #{response}"
    rescue RequiresServerEvaluation, InconclusiveMatchError => e
      logger.debug "Failed to compute flag #{key} locally: #{e}"
    rescue StandardError => e
      @on_error.call(-1, "Error computing flag locally: #{e}. #{e.backtrace.join("\n")}")
    end
  end

  flag_was_locally_evaluated = !response.nil?

  request_id = nil
  evaluated_at = nil
  feature_flag_error = nil

  if !flag_was_locally_evaluated && !only_evaluate_locally
    begin
      errors = []
      flags_data = get_all_flags_and_payloads(distinct_id, groups, person_properties, group_properties,
                                              only_evaluate_locally, true)
      if flags_data.key?(:featureFlags)
        flags = stringify_keys(flags_data[:featureFlags] || {})
        payloads = stringify_keys(flags_data[:featureFlagPayloads] || {})
        request_id = flags_data[:requestId]
        evaluated_at = flags_data[:evaluatedAt]
      else
        logger.debug "Missing feature flags key: #{flags_data.to_json}"
        flags = {}
        payloads = {}
      end

      status = flags_data[:status]
      errors << FeatureFlagError.api_error(status) if status && status >= 400
      errors << FeatureFlagError::ERRORS_WHILE_COMPUTING if flags_data[:errorsWhileComputingFlags]
      errors << FeatureFlagError::QUOTA_LIMITED if flags_data[:quotaLimited]&.include?('feature_flags')
      errors << FeatureFlagError::FLAG_MISSING unless flags.key?(key.to_s)

      response = flags[key]
      response = false if response.nil?
      payload = payloads[key]
      feature_flag_error = errors.join(',') unless errors.empty?

      logger.debug "Successfully computed flag remotely: #{key} -> #{response}"
    rescue Timeout::Error => e
      @on_error.call(-1, "Timeout while fetching flags remotely: #{e}")
      feature_flag_error = FeatureFlagError::TIMEOUT
    rescue Errno::ECONNRESET, Errno::ECONNREFUSED, EOFError, SocketError => e
      @on_error.call(-1, "Connection error while fetching flags remotely: #{e}")
      feature_flag_error = FeatureFlagError::CONNECTION_ERROR
    rescue StandardError => e
      @on_error.call(-1, "Error computing flag remotely: #{e}. #{e.backtrace.join("\n")}")
      feature_flag_error = FeatureFlagError::UNKNOWN_ERROR
    end
  end

  [response, flag_was_locally_evaluated, request_id, evaluated_at, feature_flag_error, payload]
end

#get_feature_flag_payload(key, distinct_id, match_value = nil, groups = {}, person_properties = {}, group_properties = {}, only_evaluate_locally = false) ⇒ Object 



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# File 'lib/posthog/feature_flags.rb', line 345

def get_feature_flag_payload(
  key,
  distinct_id,
  match_value = nil,
  groups = {},
  person_properties = {},
  group_properties = {},
  only_evaluate_locally = false
)
  if match_value.nil?
    match_value = get_feature_flag(
      key,
      distinct_id,
      groups,
      person_properties,
      group_properties,
      true
    )[0]
  end
  response = nil
  response = _compute_flag_payload_locally(key, match_value) unless match_value.nil?
  if response.nil? && !only_evaluate_locally
    flags_payloads = get_feature_payloads(distinct_id, groups, person_properties, group_properties)
    response = flags_payloads[key.downcase] || nil
  end
  response
end

#get_feature_payloads(distinct_id, groups = {}, person_properties = {}, group_properties = {}, _only_evaluate_locally = false) ⇒ Object 



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# File 'lib/posthog/feature_flags.rb', line 95

def get_feature_payloads(
  distinct_id,
  groups = {},
  person_properties = {},
  group_properties = {},
  _only_evaluate_locally = false
)
  flags_data = get_all_flags_and_payloads(
    distinct_id,
    groups,
    person_properties,
    group_properties
  )

  if flags_data.key?(:featureFlagPayloads)
    stringify_keys(flags_data[:featureFlagPayloads] || {})
  else
    logger.debug "Missing feature flag payloads key: #{flags_data.to_json}"
    {}
  end
end

#get_feature_variants(distinct_id, groups = {}, person_properties = {}, group_properties = {}, only_evaluate_locally = false, raise_on_error = false) ⇒ Object 



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# File 'lib/posthog/feature_flags.rb', line 69

def get_feature_variants(
  distinct_id,
  groups = {},
  person_properties = {},
  group_properties = {},
  only_evaluate_locally = false,
  raise_on_error = false
)
  # TODO: Convert to options hash for easier argument passing
  flags_data = get_all_flags_and_payloads(
    distinct_id,
    groups,
    person_properties,
    group_properties,
    only_evaluate_locally,
    raise_on_error
  )

  if flags_data.key?(:featureFlags)
    stringify_keys(flags_data[:featureFlags] || {})
  else
    logger.debug "Missing feature flags key: #{flags_data.to_json}"
    {}
  end
end

#get_flags(distinct_id, groups = {}, person_properties = {}, group_properties = {}) ⇒ Object 



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# File 'lib/posthog/feature_flags.rb', line 117

def get_flags(distinct_id, groups = {}, person_properties = {}, group_properties = {})
  request_data = {
    distinct_id: distinct_id,
    groups: groups,
    person_properties: person_properties,
    group_properties: group_properties
  }

  flags_response = _request_feature_flag_evaluation(request_data)

  # Only normalize if we have flags in the response
  if flags_response[:flags]
    # v4 format
    flags_hash = flags_response[:flags].transform_values do |flag|
      FeatureFlag.new(flag)
    end
    flags_response[:flags] = flags_hash
    # Filter out flags that failed evaluation to avoid overwriting cached values
    successful_flags = flags_hash.reject { |_, flag| flag.failed == true }
    flags_response[:featureFlags] = successful_flags.transform_values(&:get_value).transform_keys(&:to_sym)
    flags_response[:featureFlagPayloads] = successful_flags.transform_values(&:payload).transform_keys(&:to_sym)
  elsif flags_response[:featureFlags]
    # v3 format
    flags_response[:featureFlags] = flags_response[:featureFlags] || {}
    flags_response[:featureFlagPayloads] = flags_response[:featureFlagPayloads] || {}
    flags_response[:flags] = flags_response[:featureFlags].to_h do |key, value|
      [key, FeatureFlag.from_value_and_payload(key, value, flags_response[:featureFlagPayloads][key])]
    end
  end

  flags_response
end

#get_matching_variant(flag, distinct_id) ⇒ Object 



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# File 'lib/posthog/feature_flags.rb', line 986

def get_matching_variant(flag, distinct_id)
  hash_value = _hash(flag[:key], distinct_id, 'variant')
  matching_variant = variant_lookup_table(flag).find do |variant|
    hash_value >= variant[:value_min] and hash_value < variant[:value_max]
  end
  matching_variant.nil? ? nil : matching_variant[:key]
end

#get_remote_config_payload(flag_key) ⇒ Object 



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# File 'lib/posthog/feature_flags.rb', line 150

def get_remote_config_payload(flag_key)
  _request_remote_config_payload(flag_key)
end

#load_feature_flags(force_reload = false) ⇒ Object 



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# File 'lib/posthog/feature_flags.rb', line 63

def load_feature_flags(force_reload = false)
  return unless @loaded_flags_successfully_once.false? || force_reload

  _load_feature_flags
end

#match_feature_flag_properties(flag, distinct_id, properties, evaluation_cache, cohort_properties = {}) ⇒ Object 



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# File 'lib/posthog/feature_flags.rb', line 915

def match_feature_flag_properties(flag, distinct_id, properties, evaluation_cache, cohort_properties = {})
  flag_filters = flag[:filters] || {}

  flag_conditions = flag_filters[:groups] || []
  is_inconclusive = false
  result = nil

  # NOTE: This NEEDS to be `each` because `each_key` breaks
  flag_conditions.each do |condition|
    if condition_match(flag, distinct_id, condition, properties, evaluation_cache, cohort_properties)
      variant_override = condition[:variant]
      flag_multivariate = flag_filters[:multivariate] || {}
      flag_variants = flag_multivariate[:variants] || []
      variant = if flag_variants.map { |variant| variant[:key] }.include?(condition[:variant])
                  variant_override
                else
                  get_matching_variant(flag, distinct_id)
                end
      result = variant || true
      break
    end
  rescue RequiresServerEvaluation
    # Static cohort or other missing server-side data - must fallback to API
    raise
  rescue InconclusiveMatchError
    # Evaluation error (bad regex, invalid date, missing property, etc.)
    # Track that we had an inconclusive match, but try other conditions
    is_inconclusive = true
  end

  if !result.nil?
    return result
  elsif is_inconclusive
    raise InconclusiveMatchError, "Can't determine if feature flag is enabled or not with given properties"
  end

  # We can only return False when all conditions are False
  false
end

#shutdown_poller ⇒ Object 



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# File 'lib/posthog/feature_flags.rb', line 373

def shutdown_poller
  @task.shutdown
end

#variant_lookup_table(flag) ⇒ Object 



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# File 'lib/posthog/feature_flags.rb', line 994

def variant_lookup_table(flag)
  lookup_table = []
  value_min = 0
  flag_filters = flag[:filters] || {}
  variants = flag_filters[:multivariate] || {}
  multivariates = variants[:variants] || []
  multivariates.each do |variant|
    value_max = value_min + (variant[:rollout_percentage].to_f / 100)
    lookup_table << { value_min: value_min, value_max: value_max, key: variant[:key] }
    value_min = value_max
  end
  lookup_table
end