Class: RailsErrorDashboard::Services::BacktraceProcessor

Inherits:
Object
  • Object
show all
Defined in:
lib/rails_error_dashboard/services/backtrace_processor.rb

Overview

Pure algorithm service for backtrace processing Handles truncation and signature generation with no database access.

Class Method Summary collapse

Class Method Details

.calculate_signature(backtrace, locations: nil) ⇒ String?

Calculate a signature hash from backtrace for fuzzy similarity matching Extracts file paths and method names, ignoring line numbers, then produces an order-independent SHA256 digest.

Parameters:

  • backtrace (String, Array<String>, nil) —

    The backtrace

  • locations (Array<Thread::Backtrace::Location>, nil) (defaults to: nil) —

    Optional structured locations

Returns:

  • (String, nil) —

    16-character hex signature



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# File 'lib/rails_error_dashboard/services/backtrace_processor.rb', line 76

def self.calculate_signature(backtrace, locations: nil)
  # Try structured locations first (more reliable, no regex)
  if locations && !locations.empty?
    return signature_from_locations(locations)
  end

  return nil if backtrace.blank?

  lines = backtrace.is_a?(String) ? backtrace.split("\n") : backtrace
  frames = lines.first(20).map do |line|
    if line =~ %r{([^/]+\.rb):.*?in `(.+)'$}
      "#{Regexp.last_match(1)}:#{Regexp.last_match(2)}"
    elsif line =~ %r{([^/]+\.rb)}
      Regexp.last_match(1)
    end
  end.compact.uniq

  return nil if frames.empty?

  file_paths = frames.map { |frame| frame.split(":").first }.sort
  Digest::SHA256.hexdigest(file_paths.join("|"))[0..15]
end

.shorten_gem_path(line) ⇒ String

Shorten gem/ruby paths to remove user-specific prefixes. Preserves gem name + version for debugging.

Examples:

/home/user/.gem/ruby/3.4.0/gems/rack-3.2.6/lib/rack/head.rb:15
→ gems/rack-3.2.6/lib/rack/head.rb:15

/home/user/.local/share/mise/installs/ruby/4.0.2/lib/ruby/4.0.0/net/http.rb:1234
→ ruby/4.0.0/net/http.rb:1234

/home/user/myapp/app/controllers/users_controller.rb:10
→ app/controllers/users_controller.rb:10

Parameters:

  • line (String) —

    A single backtrace line

Returns:

  • (String) —

    The line with shortened path



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# File 'lib/rails_error_dashboard/services/backtrace_processor.rb', line 51

def self.shorten_gem_path(line)
  # Strip everything before /gems/ (gem code)
  if line.include?("/gems/")
    line.sub(%r{^.*/gems/}, "gems/")
  # Strip everything before /lib/ruby/ (Ruby stdlib)
  elsif line.include?("/lib/ruby/")
    line.sub(%r{^.*/lib/ruby/}, "ruby/")
  # Strip everything before /app/ (application code)
  elsif line.include?("/app/")
    line.sub(%r{^.*/app/}, "app/")
  # Strip everything before /lib/ for app lib code (but not gem/ruby paths already handled)
  elsif line.include?("/lib/")
    line.sub(%r{^.*/lib/}, "lib/")
  else
    line
  end
end

.truncate(backtrace, max_lines: nil) ⇒ String?

Truncate backtrace to a maximum number of lines and shorten gem paths.

Gem paths like:

/home/user/.local/share/mise/installs/ruby/4.0.2/lib/ruby/gems/4.0.0/gems/actionpack-8.1.3/lib/...

are shortened to:

gems/actionpack-8.1.3/lib/...

This saves significant disk space without losing debugging value (issue #115).

Parameters:

  • backtrace (Array<String>, nil) —

    The backtrace lines

  • max_lines (Integer) (defaults to: nil) —

    Maximum lines to keep

Returns:

  • (String, nil) —

    Truncated backtrace as a single string



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# File 'lib/rails_error_dashboard/services/backtrace_processor.rb', line 20

def self.truncate(backtrace, max_lines: nil)
  return nil if backtrace.nil?

  max_lines ||= RailsErrorDashboard.configuration.max_backtrace_lines

  limited_backtrace = backtrace.first(max_lines).map { |line| shorten_gem_path(line) }
  result = limited_backtrace.join("\n")

  if backtrace.length > max_lines
    truncation_notice = "... (#{backtrace.length - max_lines} more lines truncated)"
    result = result.empty? ? truncation_notice : result + "\n" + truncation_notice
  end

  result
end