Class: LogStruct::Formatter

Inherits:
Logger::Formatter
  • Object
show all
Extended by:
T::Sig
Defined in:
lib/log_struct/formatter.rb

Instance Method Summary collapse

Instance Method Details

#call(severity, time, progname, log_value) ⇒ String

Serializes Log (or string) into JSON

Parameters:

  • severity (String, Symbol, Integer)
  • time (Time)
  • progname (String, nil)
  • log_value (T.untyped)

Returns:

  • (String) 


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# File 'lib/log_struct/formatter.rb', line 185

def call(severity, time, progname, log_value)
  level_enum = Level.from_severity(severity)

  data = log_value_to_hash(log_value, time: time)

  # Filter params, scrub sensitive values, format ActiveJob GlobalID arguments
  data = process_values(data)

  # Add standard fields if not already present
  data[:src] ||= Source::App
  data[:evt] ||= Event::Log
  data[:ts] ||= time.iso8601(3)
  data[:lvl] = level_enum # Set level from severity parameter
  data[:prog] = progname if progname.present?

  generate_json(data)
end

#clear_tags! ⇒ void

This method returns an undefined value.

Add clear_tags! method to support ActiveSupport::TaggedLogging



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# File 'lib/log_struct/formatter.rb', line 37

def clear_tags!
  Thread.current[:activesupport_tagged_logging_tags] = []
end

#current_tags ⇒ Array<String>

Add current_tags method to support ActiveSupport::TaggedLogging

Returns:

  • (Array<String>) 


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# File 'lib/log_struct/formatter.rb', line 21

def current_tags
  Thread.current[:activesupport_tagged_logging_tags] ||= []
end

#generate_json(data) ⇒ String

Output as JSON with a newline. We mock this method in tests so we can inspect the data right before it gets turned into a JSON string.

Parameters:

  • data (Hash{T.untyped => T.untyped})

Returns:

  • (String) 


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# File 'lib/log_struct/formatter.rb', line 206

def generate_json(data)
  "#{data.to_json}\n"
end

#log_value_to_hash(log_value, time:) ⇒ Hash{Symbol => T.untyped}

Parameters:

  • log_value (T.untyped)
  • time (Time)

Returns:

  • (Hash{Symbol => T.untyped}) 


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# File 'lib/log_struct/formatter.rb', line 123

def log_value_to_hash(log_value, time:)
  case log_value
  when Log::Interfaces::CommonFields
    # Our log classes all implement a custom #serialize method that use symbol keys
    log_value.serialize

  when T::Struct
    # Default T::Struct.serialize methods returns a hash with string keys, so convert them to symbols
    log_value.serialize.deep_symbolize_keys

  when Hash
    # Use hash as is and convert string keys to symbols
    log_value.dup.deep_symbolize_keys

  else
    # Create a Plain log with the message as a string and serialize it with symbol keys
    # log_value can be literally anything: Integer, Float, Boolean, NilClass, etc.
    log_message = case log_value
    # Handle all the basic types without any further processing
    when String, Symbol, TrueClass, FalseClass, NilClass, Array, Hash, Time, Numeric
      log_value
    else
      # Handle the serialization of complex objects in a useful way:
      #
      # 1. For ActiveRecord models: Use as_json which includes attributes
      # 2. For objects with custom as_json implementations: Use their implementation
      # 3. For basic objects that only have ActiveSupport's as_json: Use to_s
      begin
        method_owner = log_value.method(:as_json).owner

        # If it's ActiveRecord, ActiveModel, or a custom implementation, use as_json
        if method_owner.to_s.include?("ActiveRecord") ||
            method_owner.to_s.include?("ActiveModel") ||
            method_owner.to_s.exclude?("ActiveSupport::CoreExtensions") &&
                method_owner.to_s.exclude?("Object")
          log_value.as_json
        else
          # For plain objects with only the default ActiveSupport as_json
          log_value.to_s
        end
      rescue => e
        # Handle serialization errors
        context = {
          object_class: log_value.class.name,
          object_inspect: log_value.inspect.truncate(100)
        }
        LogStruct.handle_exception(e, source: Source::LogStruct, context: context)

        # Fall back to the string representation to ensure we continue processing
        log_value.to_s
      end
    end

    Log::Plain.new(
      message: log_message,
      timestamp: time
    ).serialize
  end
end

#looks_like_backtrace?(array) ⇒ Boolean

Check if an array looks like a backtrace (array of strings with file:line pattern)

Parameters:

  • array (Array<T.untyped>)

Returns:

  • (Boolean) 


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# File 'lib/log_struct/formatter.rb', line 212

def looks_like_backtrace?(array)
  return false if array.empty?

  # Check if most elements look like backtrace lines (file.rb:123 or similar patterns)
  backtrace_like_count = array.first(5).count do |element|
    element.is_a?(String) && element.match?(/\A[^:\s]+:\d+/)
  end

  # If at least 3 out of the first 5 elements look like backtrace lines, treat as backtrace
  backtrace_like_count >= 3
end

#process_values(arg, recursion_depth: 0) ⇒ T.untyped

Parameters:

  • arg (T.untyped)
  • recursion_depth (Integer) (defaults to: 0)

Returns:

  • (T.untyped) 


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# File 'lib/log_struct/formatter.rb', line 53

def process_values(arg, recursion_depth: 0)
  # Prevent infinite recursion in case any args have circular references
  # or are too deeply nested. Just return args.
  return arg if recursion_depth > 20

  case arg
  when Hash
    result = {}

    # Process each key-value pair
    arg.each do |key, value|
      # Check if this key should be filtered at any depth
      result[key] = if ParamFilters.should_filter_key?(key)
        # Filter the value
        {_filtered: ParamFilters.summarize_json_attribute(key, value)}
      else
        # Process the value normally
        process_values(value, recursion_depth: recursion_depth + 1)
      end
    end

    result
  when Array
    result = arg.map { |value| process_values(value, recursion_depth: recursion_depth + 1) }

    # Filter large arrays, but don't truncate backtraces (arrays of strings that look like file:line)
    if result.size > 10 && !looks_like_backtrace?(result)
      result = result.take(10) + ["... and #{result.size - 10} more items"]
    end
    result
  when GlobalID::Identification
    begin
      arg.to_global_id
    rescue
      begin
        case arg
        when ActiveRecord::Base
          "#{arg.class}(##{arg.id})"
        else
          # For non-ActiveRecord objects that failed to_global_id, try to get a string representation
          # If this also fails, we want to catch it and return the error placeholder
          T.unsafe(arg).to_s
        end
      rescue => e
        LogStruct.handle_exception(e, source: Source::LogStruct)
        "[GLOBALID_ERROR]"
      end
    end
  when Source, Event
    arg.serialize
  when String
    scrub_string(arg)
  when Time
    arg.iso8601(3)
  else
    # Any other type (e.g. Symbol, Integer, Float, Boolean etc.)
    arg
  end
rescue => e
  # Report error through LogStruct's framework
  context = {
    processor_method: "process_values",
    value_type: arg.class.name,
    recursion_depth: recursion_depth
  }
  LogStruct.handle_exception(e, source: Source::LogStruct, context: context)
  arg
end

#push_tags(*tags) ⇒ T.untyped

Parameters:

  • tags (Array<String>)

Returns:

  • (T.untyped) 


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# File 'lib/log_struct/formatter.rb', line 42

def push_tags(*tags)
  current_tags.concat(tags)
end

#scrub_string(string) ⇒ String

Parameters:

  • string (String)

Returns:

  • (String) 


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# File 'lib/log_struct/formatter.rb', line 47

def scrub_string(string)
  # Use StringScrubber module to scrub sensitive information from strings
  StringScrubber.scrub(string)
end

#tagged(*tags, &blk) ⇒ T.untyped

Add tagged method to support ActiveSupport::TaggedLogging

Parameters:

  • tags (Array<String>)
  • blk (T.proc.params(formatter: Formatter).void)

Returns:

  • (T.untyped) 


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# File 'lib/log_struct/formatter.rb', line 27

def tagged(*tags, &blk)
  new_tags = tags.flatten
  current_tags.concat(new_tags) if new_tags.any?
  yield self
ensure
  current_tags.pop(new_tags.size) if new_tags&.any?
end