config: factor out exception_handler hook to a separate classexception-handler-refactoring

3 files changed, 43 insertions, 22 deletions

diff --git a/lib/pry.rb b/lib/pry.rb
index 4596ed2c..1c972b7d 100644
--- a/lib/pry.rb
+++ b/lib/pry.rb
@@ -21,6 +21,7 @@ require 'pry/syntax_highlighter'
 require 'pry/editor'
 require 'pry/history'
 require 'pry/color_printer'
+require 'pry/exception_handler'
 
 Pry::Commands = Pry::CommandSet.new unless defined?(Pry::Commands)
 
diff --git a/lib/pry/config.rb b/lib/pry/config.rb
index 6b7e4fcf..6fcf9920 100644
--- a/lib/pry/config.rb
+++ b/lib/pry/config.rb
@@ -7,7 +7,6 @@ class Pry
     # @return [Pry::Config]
     #   An object who implements the default configuration for all
     #   Pry sessions.
-    # rubocop:disable Metrics/AbcSize
     def self.defaults
       defaults = from_hash(
         input: Pry.lazy { lazy_readline(defaults) },
@@ -18,26 +17,7 @@ class Pry
         prompt_safe_contexts: Pry::Prompt::SAFE_CONTEXTS,
         print: Pry::ColorPrinter.method(:default),
         quiet: false,
-
-        # Will only show the first line of the backtrace
-        exception_handler: proc do |output, exception, _|
-          if exception.is_a?(UserError) && exception.is_a?(SyntaxError)
-            output.puts "SyntaxError: #{exception.message.sub(/.*syntax error, */m, '')}"
-          else
-            output.puts "#{exception.class}: #{exception.message}"
-            output.puts "from #{exception.backtrace.first}"
-
-            if exception.respond_to? :cause
-              cause = exception.cause
-              while cause
-                output.puts "Caused by #{cause.class}: #{cause}\n"
-                output.puts "from #{cause.backtrace.first}"
-                cause = cause.cause
-              end
-            end
-          end
-        end,
-
+        exception_handler: Pry::ExceptionHandler.method(:handle_exception),
         unrescued_exceptions: [
           ::SystemExit, ::SignalException, Pry::TooSafeException
         ],
@@ -113,7 +93,6 @@ class Pry
         exec_string: ""
       )
     end
-    # rubocop:enable Metrics/AbcSize
 
     def self.shortcuts
       Convenience::SHORTCUTS
diff --git a/lib/pry/exception_handler.rb b/lib/pry/exception_handler.rb
new file mode 100644
index 00000000..9b50fe80
--- /dev/null
+++ b/lib/pry/exception_handler.rb
@@ -0,0 +1,41 @@
+class Pry
+  # @api private
+  # @since ?.?.?
+  module ExceptionHandler
+    class << self
+      # Will only show the first line of the backtrace.
+      def handle_exception(output, exception, _pry_instance)
+        if exception.is_a?(UserError) && exception.is_a?(SyntaxError)
+          output.puts "SyntaxError: #{exception.message.sub(/.*syntax error, */m, '')}"
+        else
+          output.puts standard_error_text_for(exception)
+        end
+      end
+
+      private
+
+      def standard_error_text_for(exception)
+        text = exception_text(exception)
+        return text unless exception.respond_to?(:cause)
+
+        cause = exception.cause
+        while cause
+          text += cause_text(cause)
+          cause = cause.cause
+        end
+
+        text
+      end
+
+      def exception_text(exception)
+        "#{exception.class}: #{exception.message}\n" \
+        "from #{exception.backtrace.first}\n"
+      end
+
+      def cause_text(cause)
+        "Caused by #{cause.class}: #{cause}\n" \
+        "from #{cause.backtrace.first}\n"
+      end
+    end
+  end
+end