1 files changed, 16 insertions, 10 deletions
diff --git a/lib/rack/show_exceptions.rb b/lib/rack/show_exceptions.rb
index ca86b2b2..843af607 100644
--- a/lib/rack/show_exceptions.rb
+++ b/lib/rack/show_exceptions.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
  require 'ostruct'
  require 'erb'
  require 'rack/request'
@@ -46,7 +48,7 @@ module Rack
      end
  
      def prefers_plaintext?(env)
-      !accepts_html(env)
+      !accepts_html?(env)
      end
  
      def accepts_html?(env)
@@ -55,7 +57,7 @@ module Rack
      private :accepts_html?
  
      def dump_exception(exception)
-      string = "#{exception.class}: #{exception.message}\n"
+      string = "#{exception.class}: #{exception.message}\n".dup
        string << exception.backtrace.map { |l| "\t#{l}" }.join("\n")
        string
      end
@@ -77,13 +79,13 @@ module Rack
            frame.function = $4
  
            begin
-            lineno = frame.lineno-1
+            lineno = frame.lineno - 1
              lines = ::File.readlines(frame.filename)
-            frame.pre_context_lineno = [lineno-CONTEXT, 0].max
+            frame.pre_context_lineno = [lineno - CONTEXT, 0].max
              frame.pre_context = lines[frame.pre_context_lineno...lineno]
              frame.context_line = lines[lineno].chomp
-            frame.post_context_lineno = [lineno+CONTEXT, lines.size].min
-            frame.post_context = lines[lineno+1..frame.post_context_lineno]
+            frame.post_context_lineno = [lineno + CONTEXT, lines.size].min
+            frame.post_context = lines[lineno + 1..frame.post_context_lineno]
            rescue
            end
  
@@ -93,7 +95,11 @@ module Rack
          end
        }.compact
  
-      TEMPLATE.result(binding)
+      template.result(binding)
+    end
+
+    def template
+      TEMPLATE
      end
  
      def h(obj)                  # :nodoc:
@@ -107,8 +113,8 @@ module Rack
  
      # :stopdoc:
  
-    # adapted from Django <djangoproject.com>
-    # Copyright (c) 2005, the Lawrence Journal-World
+    # adapted from Django <www.djangoproject.com>
+    # Copyright (c) Django Software Foundation and individual contributors.
      # Used under the modified BSD license:
      # http://www.xfree86.org/3.3.6/COPYRIGHT2.html#5
      TEMPLATE = ERB.new(<<-'HTML'.gsub(/^      /, ''))
@@ -363,7 +369,7 @@ module Rack
                  <% env.sort_by { |k, v| k.to_s }.each { |key, val| %>
                  <tr>
                    <td><%=h key %></td>
-                  <td class="code"><div><%=h val %></div></td>
+                  <td class="code"><div><%=h val.inspect %></div></td>
                  </tr>
                  <% } %>
              </tbody>