class ActiveSupport::BacktraceCleaner
Inspired by the Quiet Backtrace gem by thoughtbot.
These two methods will give you a completely untouched backtrace.
of the backtrace, you can call BacktraceCleaner#remove_filters!
BacktraceCleaner so that it does not filter or modify the paths of any lines
backtrace to a pristine state. If you need to reconfigure an existing
BacktraceCleaner#remove_silencers!, which will restore the
and show as much data as possible, you can always call
To reconfigure an existing BacktraceCleaner (like the default one in Rails)
bc.clean(exception.backtrace) # perform the cleanup
bc.add_silencer { |line| /puma|rubygems/.match?(line) } # skip any lines from puma or rubygems
bc.add_filter { |line| line.gsub(Rails.root.to_s, ”) } # strip the Rails.root prefix
bc = ActiveSupport::BacktraceCleaner.new
can focus on the rest.
is to exclude the output of a noisy library from the backtrace, so that you
app directory instead of the file system root. The typical silencer use case
information from the start of each line, and view file paths relevant to the
lines entirely. The typical filter use case is to remove lengthy path
Filters are used to modify lines of data, while silencers are used to remove
lines remain.
silencers are used to remove the noisy lines, so that only the most relevant
noise, and adds debugging time. With a BacktraceCleaner, filters and
under review. This makes it hard to find the signal amongst the backtrace
Backtraces often include many lines that are not relevant for the context
def add_filter(&block)
# Will turn "/my/rails/root/app/models/person.rb" into "/app/models/person.rb"
mapped against this filter.
Adds a filter from the block provided. Each line in the backtrace will be
def add_filter(&block) @filters << block end
def add_gem_filter
def add_gem_filter gems_paths = (Gem.path | [Gem.default_dir]).map { |p| Regexp.escape(p) } return if gems_paths.empty? gems_regexp = %r{\A(#{gems_paths.join('|')})/(bundler/)?gems/([^/]+)-([\w.]+)/(.*)} gems_result = '\3 (\4) \5' add_filter { |line| line.sub(gems_regexp, gems_result) } end
def add_gem_silencer
def add_gem_silencer add_silencer { |line| FORMATTED_GEMS_PATTERN.match?(line) } end
def add_silencer(&block)
# Will reject all lines that include the word "puma", like "/gems/puma/server.rb" or "/app/my_puma_server/rb"
for a given line, it will be excluded from the clean backtrace.
Adds a silencer from the block provided. If the silencer returns +true+
def add_silencer(&block) @silencers << block end
def add_stdlib_silencer
def add_stdlib_silencer add_silencer { |line| line.start_with?(RbConfig::CONFIG["rubylibdir"]) } end
def clean(backtrace, kind = :silent)
Returns the backtrace after all filters and silencers have been run
def clean(backtrace, kind = :silent) filtered = filter_backtrace(backtrace) case kind when :silent silence(filtered) when :noise noise(filtered) else filtered end end
def filter_backtrace(backtrace)
def filter_backtrace(backtrace) @filters.each do |f| backtrace = backtrace.map { |line| f.call(line) } end backtrace end
def initialize
def initialize @filters, @silencers = [], [] add_gem_filter add_gem_silencer add_stdlib_silencer end
def noise(backtrace)
def noise(backtrace) backtrace.select do |line| @silencers.any? do |s| s.call(line) end end end
def remove_filters!
need to see entire filepaths in the backtrace that you had already
Removes all filters, but leaves in the silencers. Useful if you suddenly
def remove_filters! @filters = [] end
def remove_silencers!
context of debugging suddenly expands as you suspect a bug in one of
Removes all silencers, but leaves in the filters. Useful if your
def remove_silencers! @silencers = [] end
def silence(backtrace)
def silence(backtrace) @silencers.each do |s| backtrace = backtrace.reject { |line| s.call(line) } end backtrace end