move example code to be above reconfiguring discussion; add clarity about silencers and filters; misc grammar changes - for backtrace cleaners

1 files changed, 16 insertions, 11 deletions

diff --git a/activesupport/lib/active_support/backtrace_cleaner.rb b/activesupport/lib/active_support/backtrace_cleaner.rb
index 0e6bc30fa2..8f8deb9692 100644
--- a/activesupport/lib/active_support/backtrace_cleaner.rb
+++ b/activesupport/lib/active_support/backtrace_cleaner.rb
@@ -1,12 +1,12 @@
 module ActiveSupport
-  # Many backtraces include too much information that's not relevant for the context. This makes it hard to find the signal
-  # in the backtrace and adds debugging time. With a BacktraceCleaner, you can setup filters and silencers for your particular
-  # context, so only the relevant lines are included.
+  # Backtraces often include many lines that are not relevant for the context under review. This makes it hard to find the 
+  # signal amongst the backtrace noise, and adds debugging time. With a BacktraceCleaner, filters and silencers are used to
+  # remove the noisy lines, so that only the most relevant lines remain.
   #
-  # If you need to reconfigure an existing BacktraceCleaner, like the one in Rails, to show as much as possible, you can always
-  # call BacktraceCleaner#remove_silencers! Also, if you need to reconfigure an existing BacktraceCleaner so that it does not
-  # filter or modify the paths of any lines of the backtrace, you can call BacktraceCleaner#remove_filters! These two methods
-  # will give you a completely untouched backtrace.
+  # Filters are used to modify lines of data, while silencers are used to remove lines entirely.  The typical filter use case
+  # is to remove lengthy path information from the start of each line, and view file paths relevant to the app directory 
+  # instead of the file system root.  The typical silencer use case is to exclude the output of a noisy library from the 
+  # backtrace, so that you can focus on the rest.
   #
   # ==== Example:
   #
@@ -15,13 +15,18 @@ module ActiveSupport
   #   bc.add_silencer { |line| line =~ /mongrel|rubygems/ }
   #   bc.clean(exception.backtrace) # will strip the Rails.root prefix and skip any lines from mongrel or rubygems
   #
+  # To reconfigure an existing BacktraceCleaner (like the default one in Rails) and show as much data as possible, you can 
+  # always call <tt>BacktraceCleaner#remove_silencers!</tt>, which will restore the backtrace to a pristine state.  If you 
+  # need to reconfigure an existing BacktraceCleaner so that it does not filter or modify the paths of any lines of the 
+  # backtrace, you can call BacktraceCleaner#remove_filters! These two methods will give you a completely untouched backtrace.
+  #
   # Inspired by the Quiet Backtrace gem by Thoughtbot.
   class BacktraceCleaner
     def initialize
       @filters, @silencers = [], []
     end
 
-    # Returns the backtrace after all filters and silencers has been run against it. Filters run first, then silencers.
+    # Returns the backtrace after all filters and silencers have been run against it. Filters run first, then silencers.
     def clean(backtrace, kind = :silent)
       filtered = filter(backtrace)
 
@@ -45,8 +50,8 @@ module ActiveSupport
       @filters << block
     end
 
-    # Adds a silencer from the block provided. If the silencer returns true for a given line, it'll be excluded from the
-    # clean backtrace.
+    # Adds a silencer from the block provided. If the silencer returns true for a given line, it will be excluded from 
+    # the clean backtrace.
     #
     # Example:
     #
@@ -57,7 +62,7 @@ module ActiveSupport
     end
 
     # Will remove all silencers, but leave in the filters. This is useful if your context of debugging suddenly expands as
-    # you suspect a bug in the libraries you use.
+    # you suspect a bug in one of the libraries you use.
     def remove_silencers!
       @silencers = []
     end