lua_error.rb in wolverine-0.2.3

- old
+ new

@@ -1,31 +1,45 @@
 module Wolverine
+  # Reformats errors raised by redis representing failures while executing
+  # a lua script. The default errors have confusing messages and backtraces,
+  # and a type of +RuntimeError+. This class improves the message and
+  # modifies the backtrace to include the lua script itself in a reasonable
+  # way.
   class LuaError < StandardError
     PATTERN = /ERR Error (compiling|running) script \(.*?\): \[.*?\]:(\d+): (.*)/
     WOLVERINE_LIB_PATH = File.expand_path('../../', __FILE__)
 
-    def self.intercepts?(e)
-      e.message =~ PATTERN
+    # Is this error one that should be reformatted?
+    #
+    # @param error [StandardError] the original error raised by redis
+    # @return [Boolean] is this an error that should be reformatted?
+    def self.intercepts? error
+      error.message =~ PATTERN
     end
 
-    attr_reader :error, :file
-    def initialize(error, file)
+    # Initialize a new {LuaError} from an existing redis error, adjusting
+    # the message and backtrace in the process.
+    #
+    # @param error [StandardError] the original error raised by redis
+    # @param file [Pathname] full path to the lua file the error ocurred in
+    def initialize error, file
       @error = error
       @file = file
 
-      error.message =~ PATTERN
+      @error.message =~ PATTERN
       stage, line_number, message = $1, $2, $3
 
-
-      super(message)
-      set_backtrace generate_backtrace(file, line_number)
+      super message
+      set_backtrace generate_backtrace file, line_number
     end
 
+    private
+
     def generate_backtrace(file, line_number)
-      pre_wolverine = backtrace_before_entering_wolverine(error.backtrace)
-      index_of_first_wolverine_line = (error.backtrace.size - pre_wolverine.size - 1)
-      pre_wolverine.unshift(error.backtrace[index_of_first_wolverine_line])
+      pre_wolverine = backtrace_before_entering_wolverine(@error.backtrace)
+      index_of_first_wolverine_line = (@error.backtrace.size - pre_wolverine.size - 1)
+      pre_wolverine.unshift(@error.backtrace[index_of_first_wolverine_line])
       pre_wolverine.unshift("#{file}:#{line_number}")
       pre_wolverine
     end
 
     def backtrace_before_entering_wolverine(backtrace)
@@ -36,6 +50,6 @@
       line.split(':').first.include?(WOLVERINE_LIB_PATH)
     end
 
   end
 
-end
\ No newline at end of file
+end