导轨回溯消音器不起作用，而过滤器起作用

新的 Rails 4.2 设置。我想抑制长错误回溯。在下面的回溯日志中，第一行对我来说就足够了，接下来的 4 行可以删除

ActionController::RoutingError (No route matches [GET] "/user"):
  actionpack (4.2.1) lib/action_dispatch/middleware/debug_exceptions.rb:21:in `call'
  web-console (2.1.2) lib/web_console/middleware.rb:37:in `call'
  actionpack (4.2.1) lib/action_dispatch/middleware/show_exceptions.rb:30:in `call'
  railties (4.2.1) lib/rails/rack/logger.rb:38:in `call_app'

我添加了一个新的消音器backtrace_silencers.rb

# config/initializers/backtrace_silencers.rb
Rails.backtrace_cleaner.add_silencer { |line| line =~ /lib/ }

服务器重新启动后 - 没有任何反应，我仍然得到相同的回溯日志。 （每行匹配/lib/应该被删除：http://api.rubyonrails.org/classes/ActiveSupport/BacktraceCleaner.htm)

完整性检查：

> line = "actionpack (4.2.1) lib/action_dispatch/middleware/debug_exceptions.rb:21:in `call'"
=> "actionpack (4.2.1) lib/action_dispatch/middleware/debug_exceptions.rb:21:in `call'"
> line =~ /lib/
=> 19

但过滤器有效：

# config/initializers/backtrace_silencers.rb
Rails.backtrace_cleaner.add_filter { |line| line.gsub('lib', 'yeah!') }

现在回溯看起来像这样：

ActionController::RoutingError (No route matches [GET] "/user"):
  actionpack (4.2.1) yeah!/action_dispatch/middleware/debug_exceptions.rb:21:in `call'
  web-console (2.1.2) yeah!/web_console/middleware.rb:37:in `call'
  actionpack (4.2.1) yeah!/action_dispatch/middleware/show_exceptions.rb:30:in `call'
  railties (4.2.1) yeah!/rails/rack/logger.rb:38:in `call_app'

希望获得有关如何使消音器工作的建议。干杯!

这是因为https://github.com/vipulnsward/rails/blob/ecc8f283cfc1b002b5141c527a827e74b770f2f0/actionpack/lib/action_dispatch/middleware/debug_exceptions.rb#L155-L156

Since application_trace为空（这是因为错误不是来自用户代码而是来自路由错误），我们正在回退到framework_trace，它不会过滤它（它只过滤噪音）。

您可以通过创建自己的 log_formatter 来实现您的目标。在你的development.rb and/or test.rb add

config.log_formatter = SilentLogger.new
config.log_formatter.add_silencer { |line| line =~ /lib/ }

并在模型中仅使用方法创建简单的类call必需的。在那里您可以根据需要修改回溯。

class SilentLogger
  def initialize
    @silencers = []
  end

  def add_silencer(&block)
    @silencers << block
  end

  def call(severity, timestamp, progname, msg)
    backtrace = (String === msg) ? "#{msg}\n" : "#{msg.inspect}\n"

    return backtrace if @silencers.empty?

    @silencers.each do |s|
      backtrace = backtrace.split("\n").delete_if { |line| s.call(line) }
    end

    backtrace.join("\n")
  end
end